Fast Fourier transform approach to strain gradient crystal plasticity: Regularization of strain localization and size effect

Amirhossein Lame Jouybari, dr. Samir El Shawish and dr. Leon Cizelj from the Reactor Engineering Division at Jožef Stefan Institute published the research article “Fast Fourier transform approach to strain gradient crystal plasticity: Regularization of strain localization and size effect” in International Journal of Plasticity, which is a highly renowned international journal in the field of plastic deformation, damage and fracture behaviour of solids.

The paper proposes a novel Strain Gradient Crystal Plasticity (SGCP) model, called the strict MicroSlip SGCP model, and investigates its Fast Fourier Transform (FFT) implementation in an in-house code to simulate strain localization and size effects of polycrystalline aggregates under external loads. The proposed model is best suited for materials with strain-softening behavior, such as neutron-irradiated metals, which can lead to the formation of strain localization bands in crystal grains and stress concentrations at grain boundaries. The FFT implementation of the model includes special numerical strategies to accelerate the resolution of equilibrium problems relying on a fixed-point algorithm. The method is demonstrated to successfully and efficiently overcome numerical instabilities associated with strain localization, providing regularized strain localization bands independent of grid resolution and controlled by a single non-local model parameter.

Figure: Simulation result of 2D polycrystalline aggregate model with 200 grains at 0.01 applied tensile strain. (a) Distribution of cumulative shear strain at grid resolution of 60 × 60 voxels per grain. Insets (b) and (c) show an enlarged region of the same quantity at two grid resolutions. Insets (d) and (e) show the corresponding von-Mises stress and rotation angle at 60 × 60 voxels per grain.

Extending intergranular normal-stress distributions using symmetries of linear-elastic polycrystalline materials

Dr. Samir El Shawish from the Reactor Engineering Division at Jožef Stefan Institute published the research article “Extending intergranular normal-stress distributions using symmetries of linear-elastic polycrystalline materials” in Acta Mechanica, which is an international journal focused on theoretical and applied mechanics.

The paper presents a novel approach to model intergranular normal-stress distributions in linear-elastic polycrystalline materials when subjected to external forces. By leveraging symmetry-based arguments, this approach demonstrates that the stress distribution can be precisely reconstructed using only the first ten statistical moments. These moments are primarily influenced by three stress invariants and a few material invariants, reflecting the macroscopic polycrystalline isotropy and material linear behavior. This innovative technique facilitates the extension of known stress distributions under particular loading conditions to those under arbitrary conditions, and thus holds significant implications for probabilistic modeling of grain boundary damage in structural materials.

Figure: Intergranular normal-stress distributions (PDFs) for different loading conditions. A comparison is shown between PDFs obtained in simulations (black) and PDFs predicted by the new method (red) using N available distributions as input (bold black).

The EUROfusion Engineering Grant (EEG) was awarded to 16 candidates from a wide range of 55 different competence areas, interesting for development of fusion technologies. The EEG was also awarded to young researcher Aljoša Gajšek from the Reactor engineering division R4, under the mentorship of Dr. Boštjan Končar (JSI) and Dr. Marianne Richou (CEA), for research of boiling under extreme conditions, found in divertors of fusion reactors. The project includes upgrading the test section of the Thermal-hydraulics experimental laboratory for multiphase applications (THELMA) at R4 division. The aim of the project is to develop a physical model to describe boiling in divertor cooling conditions.

Previous week, between April 12 and 14, the EMUG (European MELCOR and MACCS User Group) meeting was held in Slovenia, organized by the Reactor Engineering Division, JSI in cooperation with the Paul Scherrer Institute from Switzerland. The meeting was attended in-person and virtually by 66 users and developers of the computer programs MELCOR, which is used to simulate severe accidents in nuclear power plants, and MACCS, which is used to simulate the impact of these accidents on the environment. Both programs, MELCOR and MACCS, are developed by the Sandia National Laboratories, USA for the US Nuclear Regulatory Commission.

Grain boundary stresses in elastic materials

Dr. Samir El Shawish and dr. Timon Mede from the Reactor Engineering Division at Jožef Stefan Institute published an article “Grain boundary stresses in elastic materials” in European Journal of Mechanics / A Solids.

In the paper a simple analytical model is proposed for computing intergranular normal stresses induced in elastic polycrystalline materials by uniform macroscopic loading. The model is derived in a perturbative manner, where at each succeeding order additional contributions to grain-boundary-normal stresses are included – from more to less relevant. The most important effects come from grain-boundary orientation (with respect to external stress), its type and the neighbourhood of bicrystal pair of grains. In the final iteration, grain boundary becomes a part of a 3D structure consisting of five 1D chains with arbitrary number of grains, which is embedded in a homogeneous and isotropic elastic medium. Imposing 1D Reuss and Voigt approximations on different length scales, the constitutive equations can be solved in general, i.e., for arbitrary uniform loading, grain-boundary type and choice of elastic polycrystalline material, and local grain-boundary-normal stresses expressed algebraically as a function of grain-boundary type, its inclination with respect to loading direction and material-elasticity parameters.

A comparison with finite element simulations shows that while the model is not accurate enough on the local scale to predict crack-initiation sites, the corresponding statistical distribution of normal stresses on grain boundaries of a chosen type agree extremely well with those obtained numerically. Such statistical knowledge of intergranular normal stresses is a necessary prerequisite in any local damage modelling approach, e.g., to predict the probability for intergranular stress-corrosion cracking or fatigue-crack initiation in structural materials.

Figure 1: A 2D sketch of perturbative model for grain-boundary stresses, consisting of two anisotropic grains of unit size, enclosing the grain boundary, and several isotropic buffer grains of variable length, composing one axial and two (four in 3D) transverse chains.

Figure 2: Statistical stress distributions PDF(σ_nn) evaluated on three different grain-boundary types in Fe for uniaxial tensile loading. An excellent agreement between simulation results (solid lines) and model predictions (dashed lines) is shown for all three cases.

Researchers from the EUROfusion consortium, including JSI researchers, used the Joint European Torus (JET) device to release a record 59 MJ of sustained fusion energy. The breakthrough achievement on JET, the world’s most powerful operational fusion facility based in Oxford, almost tripled the previous fusion energy record. These experiments are a major boost for Iter, the larger and more advanced version of JET. Iter is an experimental fusion reactor under construction in southern France. The EUROfusion consortium, co-funded by the European Commission, integrates 4800 researchers from 30 research organisations. 8 departments and more than 40 researchers from Jožef Stefan Institute are involved in EUROfusion consortium. Dr. Boštjan Končar, R4, SFA: »The achievement is also the result of many years of hard work by Slovenian researchers, especially in the field of neutron transport calculations, diagnostics, analyses and preparation of fusion experiments.”

Boštjan Zajec, Marko Matkovič, Nejc Kosanič, Jure Oder, Blaž Mikuž, Jan Kren and Iztok Tiselj from the Reactor Engineering Division at Jožef Stefan Institute published the article “Turbulent Flow over Confined Backward-Facing Step: PIV vs. DNS” in the Applied Sciences.

The paper compares the existing Direct Numerical Simulation (DNS) of the the flow over the backward-facing step with newly performed Particle Image Velocimetry measurements in the same flow configuration exhibiting a three-dimensional nature. This is the first time that our group performed PIV measurements while we gained many experiences with high-fidelity simulations in the last decades or so.

The experiment and the simulation were performed in an identical cross-section geometry with step expansion rate 2.25 and the square shape of the outlet duct. The experiment was performed in transparent test section, 1.2 m long, with 20 × 45 mm² cross-section upstream and 45 × 45 mm² downstream, while a three-times shorter domain was used in the DNS. Reynolds number is 7100 based on the hydraulic diameter of inlet part of the section. A 2D-2C PIV system with a single high-speed camera and a pulse laser was used for a series of two-dimensional measurements of the velocity field at several cross-sections from two different perspectives. Variables analysed in the experiment are time-averaged fluid velocities, velocity RMS fluctuations and two components of the Reynolds stress tensor. Comparison of the similarities, and especially the differences between the two approaches, PIV and DNS, elucidates uncertainties of both studies and answers the question on what kind of agreement is expected when two very accurate approaches are compared.

Figure 1: Left: Test loop configuration. Top-right: Schematic of the test-section, coordinate system and measurement planes z = 0 (green) and y = 0 (blue). In parentheses: dimensionless lengths. X-length of the measurement planes is around 25 cm. Bottom-right: raw image for PIV analysis in plane z = 0.

Figure 2: Time-averaged velocity field of in plane z = 0: components u and v (top pair), u_RMS,v_RMS, u’v’ (bottom triplet). PIV experiment: color-scale and blue contours. DNS—black contours.

Prof. dr. Leon Cizelj was elected as the president of the European Nuclear Society (ENS; www.euronuclear.org) for 2022 and 2023 at the proposal of the Nuclear Society of Slovenia. Amongst the most important ENS activities are international cooperation and networking of nuclear experts by organization of scientific conferences, expert consultations and communication on nuclear science and technology. The ENS associate more than 12 000 nuclear experts from the European community, United Kingdom and Israel, working in research, higher education, industry and regulatory bodies. Presidency of the association at a time when nuclear energy and related research are becoming an increasingly important element in ensuring a low-carbon future is a strong recognition of Slovenian nuclear researchers, professionals and to prof. Cizelj personally.

New experimental campaign - Investigation of Temperature Fluctuations in a Fully Developed Channel Flow

Dr. Mohit Sharma and colleagues have performed turbulent heat transfer experiments with the heated thin foil cooled with a turbulent flow of water in a square duct. The thickness of the foil is 25 µm. Temperature fields were measured at variable Reynolds numbers, cooling water temperatures, and foil heating powers. Figure 1. shows instantaneous temperature field on the heated foil obtained with Infrared camera. Several thousand instantaneous images are taken in each measurement to obtain time-averaged properties of the turbulence under the foil.

Fig.1: Instantaneous temperature field at the outlet window 200 mm × 20 mm.

On 19 May 2021, the Young Generation Network of the Nuclear Society of Slovenia (YGN NSS), in cooperation with the Reactor Engineering Division of the Jožef Stefan Institute, organized the 8th Young Generation Nuclear Conference YGNC. Due to the coronavirus pandemic, the conference was held virtually this year. At the conference, young nuclear experts from industry and research have presented their work. The audience was firstly addressed by Janez Kokalj, president of YGN NSS, dr. Tomaž Žagar, president of NSS, prof. dr. Leon Cizelj, head of the Reactor Engineering Division, and Jadwiga Najder, vice-president of the Young Generation Network of the European Nuclear Society (ENS YGN). The conference was divided into 5 sections covering the areas of fission, fusion, experimental thermal-hydraulics and severe accidents and together 12 young nuclear experts presented their work. There were also three invited lecturers - dr. Anže Jazbec, operator and shift supervisor at the TRIGA reactor at JSI, Alexandra Ovcharenko, key account director at JSC Rusatom Overseas and Alexander Renev, technical department Deputy director at JSC Rusatom Overseas. The conference was organized and led by Boštjan Zajec, Jan Kren and Janez Kokalj (Reactor Engineering Division, JSI). The conference was attended by around 40 participants from Slovenia and abroad. In their contributions, young nuclear experts presented the direction of development in the field of nuclear energy in Slovenia.

Dr. Samir El Shawish and dr. Timon Mede from the Reactor Engineering Division at Jožef Stefan Institute, in collaboration with dr. Jeremy Hure from Université Paris-Saclay, CEA (France) published the article “A single grain boundary parameter to characterize normal stress fluctuations in materials with elastic cubic grains” in the European Journal of Mechanics / A Solids.

The paper identifies a statistical correlation between the intergranular normal stresses in a polycrystalline aggregate and the corresponding grain boundary type. The latter has been shown to be well described by a single cleverly chosen macroscopic parameter, namely the local effective Young’s modulus, which represents the average stiffness of crystal boundary neighbourhood along the grain boundary normal direction and combines its geometrical aspect with material properties. It has been demonstrated that the newly introduced parameter of effective stiffness of the pair of grains enclosing the selected boundary, together with Zener elastic anisotropy index, enables an accurate prediction of normal stress fluctuations on any grain boundary type in a material with cubic crystal structure and thus the corresponding probability for occurrence of large stresses under external loading.

The analysis is based on numerical simulations of intergranular normal stresses performed with finite element method and assuming elastic continuum grains of cubic lattice symmetry. The distributions of normal stresses at individual grain boundary types are characterized by their first two statistical moments – the mean value and the standard deviation. The largest normal stresses most likely form on grain boundaries whose normals are oriented along the stiffest direction in both adjacent grains. They increase the likelihood for crack initiation, which can lead to material degradation and fatigue processes.

Figure: (a) Standard deviation of normalized INS distributions 𝑠(𝜎𝑛𝑛∕𝛴) as a function of grain boundary type characterized by its effective Young’s modulus 𝐸12 in 𝛾-Fe. (b) Probability density functions (PDF) of 𝜎𝑛𝑛∕𝛴 belonging to different grain boundary types – from the softest corresponding to (001)-(001) grain boundaries and 𝐸12 = 0.35 to the stiffest (111)-(111) grain boundaries and 𝐸12 = 1.

Janez Kokalj, dr. Mitja Uršič and dr. Matjaž Leskovar from the Reactor Engineering Division at Jožef Stefan Institute published the article »Modelling of premixed layer formation in stratified fuel–coolant configuration« in the journal Nuclear Engineering and Design.

In the recent fuel–coolant interaction experiments performed in the stratified configuration at the SES and PULiMS facilities (KTH, Sweden), a premixed layer of ejected melt drops in water was clearly visible and was followed by strong spontaneous steam explosions.

In the paper, a model for the premixed layer formation in stratified fuel–coolant configuration, based on the bubble formation and collapse mechanism is presented. The developed model was implemented into the MC3D code (IRSN, France) and validated against the experimental results.

The presented analyses demonstrate the model capability to describe the premixed layer formation in a qualitative agreement with the available experimental data. The indirect comparison of the simulated premixed layer with the SES S1 and PULiMS E6 experiments via the strength of vapour explosion shows underestimation in simulations’ explosion strength. This indicates possible contributions to the vapour explosion from the classical melt jet breakup and additional mixing during the explosion itself.

Figure: Comparison of steam explosion development for different trigger position. Red colour represent the pressure pulse.

Dr. Matej Tekavčič from the Reactor Engineering Division at Jožef Stefan Institute in collaboration with researchers from the Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf (Germany) published the article »Validation of a morphology adaptive multi-field two-fluid model considering counter-current stratified flow with interfacial turbulence damping« in the journal Nuclear Engineering and Design.

The paper considers simulations of an isothermal counter-current stratified flow case in the channel of the WENKA (Water Entrainment Channel Karlsruhe) experiment using a morphology adaptive multi-field two-fluid modelling framework. To model the turbulent flow conditions near an interface, the modelling framework was extended with a turbulence damping model. Two turbulence damping strategies were investigated: symmetric, with damping in both phases, and asymmetric with damping only in the gas phase.

The comparison shows that the asymmetric approach offers improved prediction of turbulent kinetic energy on the liquid side of the interface, but with a cost of diminished accuracy of the predicted velocity profiles on the gas side.

The NESTet conference is dedicated to education and training in nuclear technology. After several years of silence (the last NESTet was organized by the European Society of Nuclear Experts (ENS) in Berlin in 2016), we agreed at the ENS, ENEN and the Joint Research Center of the European Commission (JRC) to revive the conference.

The program committee discussed key conference topics, invited speakers and possible side events. We have also defined a timetable for receiving abstracts and papers.

The meeting was attended by prof. dr. Leon Cizelj, Head of the Reactor Engineering Division.

In 2010, the International Atomic Energy Agency (IAEA) set up a comitee of Certified Nuclear and Radiation Safety Experts (TSOs) to promote cooperation and exchange of information. The basis for the operation of the comitee is document TECDOC-1835 (Technical and Scientific Support Organizations Providing Support to Regulatory Functions). In 2012, a board of directors was established, which is responsible for the implementation of the comitee program.

The fifteenth meeting of the Governing Board was organized by the IAEA in Vienna, Austria, from 17. to 18. of February 2020. The meeting had eight sections: (1) the inauguration, (2) the TSO initiative to support technical and research capacity in administrative functions, ( 3) report on a national empowerment development and empowerment workshop in the Republic of South Africa, (4) support for the IAEA Plenipotentiary Assembly, (5) promotion of the plenary, (6) miscellaneous, (7) presentations of other organizations, conferences and plenary meetings, and (8) conclusion. The main highlights of the committee meeting were:

• Michel van Haesendonck (Bel V) and Carla Eible-Schwaeger (GRS) are the new chairs and co-chairs of the board
• a pilot workshop on the establishment of a TSO in the Republic of South Africa
• a pilot workshop is planned in Belarus and Bangladesh
• a tool for self - evaluation of TSO capacities is being developed and tested

TSO's next conference will be held in Russia in 2022.

The meetings of the Board of Directors of the TSO Assembly were attended by Mitja Ursic from the Reactor Engineering Division of the Jozef Stefan Institute. Approximately 20 representatives of IAEA members and IAEA representatives attended.

Part of the ENEN + (Attract, Retain and Develop New Nuclear Talents Beyond Academic Curricula) project is the development and implementation of a communication strategy to familiarize nuclear stakeholders with the challenges of modern nuclear education and training. An important part of these challenges is to reduce young people's interest in studying nuclear sciences and technologies.

At the workshop, representatives of the academic sphere discussed the possible avenues for attracting more young talents to study corrosive sciences and technologies with the communications industry experts in the nuclear industry about. Improving the public image of the nuclear industry and thus the attractiveness of jobs in this sector is an important part of this process.

The workshop, organized by FORATOM at its premises in Brussels, was attended by prof. dr. Leon Cizelj, Head of Reactor Engineering Division.

Within the framework of Horizon 2020, European fusion research combines the targeted 7-year (2014-2020) EUROfusion fusion program under the auspices of the EURATOM Treaty. Within EUROfusion, a large part of the activities is devoted to the development of the DEMO demonstration fusion power plant. The Department of Reactor Engineering, IJS, is involved in this area within the WPSAE (Nuclear Safety) and WPPMI (Plant Level System Engineering, Design Integration and Physics Integration) work packages.

Between 27.1. and 29/01/2020, a meeting of the WPSAE Workshop responsible for the safety of the DEMO reactor was held in Garching, Germany. The meeting was organized at EUROfusion headquarters in Garching. At the meeting, the coordinator and the individual partners presented the implementation status of the WPSAE work package program and the program plan for 2020. The Reactor Engineering Division is involved in the project in the field of generic safety report preparation for the DEMO reactor. The meetings were attended by prof. Leon Cizelj et al. Boštjan Končar from the Department of Reactor Engineering, JSI. Prof. Cizelj presented the security report of the chapter on external risks.

In parallel, dr. On 28/01/2020 Boštjan Končar also attended a meeting of the WPPMI project aimed at defining activities and scope of work in 2020. The following day, 29.1. 2020 a meeting with the EUROfusion Program Manager and the DEMO Project Manager in the role of JSI and the preparation of the program for the next research program 2021 - 2027 was also held.

As a part of Horizon 2020, european fusion research brings together a targeted 5-year (2014-2018) EUROfusion program under the auspices of the EURATOM Treaty. Due to the 7-year horizon of Horizon 2020, the program has been extended by two years until 2020, with the same annual funding volume. The main objectives of EU fusion research are related to research in support of the ITER fusion reactor and in the long term, the realization of the DEMO demonstration fusion power plant. The EUROfusion program is implemented by a consortium of fusion research units of EU Member States (30 in total), where the Jozef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The lead partner in the consortium is the Institute for Plasma Physics (IPP), Germany.

On 11 July 2019, a PPPT (Power Plant Physics & Technology) Project Management Meeting was held at the IPP in Garching, Germany, to discuss planned activities under the 9th EC OP in 2021-2027. The activities were presented in more detail by the WPP holders within the PPPT program: WPPMI (Plant Level System Engineering, Design Integration and Physics Integration), WPBB (Breeding Blanket), WPMAT (Materials), WPMAG (Magnet system), WPTFV (Tritium , Fuelling & Vacuum Systems), WPRM (Remote Maintenance Systems), WPDIV (Divertor), WPHCD (Heating and Current Drive Systems), WPPES (Plant Electrical Systems), WPBOP (Heat Transfer, Balance-of-Plant and Site), WPDC (Diagnostic and control), WPENS (Early Neutron Source Definition and Design), WPSAE (Safety and Environment).

On July 12, 2019, the DEMO Project Board met in the same location. The Project Committee oversees the implementation of the PPPT program, which is underway to develop the DEMO demonstration fusion power plant and support research. At the meeting, the members of the project committee were briefed on the contents of the meeting of the DEMO Steering Board, the recommendations of the Technical Advisory Group (TAG), the international cooperation, the substantive and financial progress of the project implementation and the review of the WPBOP, WPCS ( Containment structures) and WPHCD.

Both meetings were attended by dr. Matjaž Leskovar from the Department of Reactor Engineering, IJS, who is a member of the DEMO Project Board.

NURETH is the most important conference related to the nuclear reactor thermal-hydraulics. At the NURETH-18 internetional conference, 545 papers were presented as well as 3 pannel discussions and 17 technical keynote addresses. Main topics were:

• Fundamental thermal hydraulics
• Computational thermal hydraulics
• Verification and validation
• Safety of existing reactors
• Severe accidnets
• Thermal hydraulics in Advanced Reactors

This year's, 18th conference (conference is bianual) was hold in Portland, USA, between August 18. and 22. and was organized by American Nuclear Society and Oregon State University. Conference was attended by Janez Kokalj from the Reactor Engineering Division, »Jožef Stefan« Institute, with a presentation »Premixed layer formation modelling in stratified melt-coolant geometry (Janez Kokalj, Matjaž Leskovar, Mitja Uršič)«.

The SOTERIA project ("Safe Long Term Operation of Light Water Reactors Based on Improved Understanding of Radiation Effects in Nuclear Structural Materials") is a four-year European project that started on 1st of september 2015 under the auspices of EURATOM in Horizon 2020. The main objective of the project is to improve understanding the aging phenomena of steels used in the manufacture of reactor vessels and its internal components. Through research in the field of aging steel, this regulator and the operator will be provided with the key information that is necessary for the safe and long-term operation of existing European nuclear power plants. The project involves a number of European research centers (including the JSI) as well as industry partners. The project is coordinated by CEA, France.

On the workshop, the results of the last four years in the form of lectures and posters were presented. IJS is involved in the development of a crystal plasticity model for the mechanical description of neutron-irradiated stainless steels, as well as in the modeling of intercrystalline boundaries to simulate the occurrence of early damage or damage. cracks. At the workshop, IJS, in collaboration with the IRSN, CNRS and CEA, presented a comparison of crystal plasticity methods based on finite element and fast Fourier transforms used in simulations of irradiated stainless steel. The study was presented in the form of a poster entitled "Spatial discretization convergence analysis of CP-FEM and CP-FFT models employed for neutron-irradiated austenitic stainless steel."

The workshop organized by TECNATOM in Miraflores de la Sierra was attended by dr. Oriol Costa and Samir El Shawish from the Reactor Engineering Division of the Joseph Stefan Institute.

The European Atomic Energy Society (EAES) is an organization founded in 1954, uniting European research organizations in the field of nuclear energy. The current most important function of EAES is the exchange of information on nuclear research guidelines in the home countries of organizations. The EAES consists of the Council and the Working Group. The joint meeting of the Council and the Working Party, which is held regularly on a yearly basis, is called a combined meeting. The current combined session was chaired by Leon Cizelj, who was elected to that post with a one-year term at the previous session of June 2018.

At this session, the following topics were discussed:

• an overview of the nuclear energy situation in the EAEC Member States in 2018;
• use of nuclear technology in medicine;
• decommissioning of research reactors;
• preserving and improving knowledge in the field of nuclear energy in Europe.

In the presentation "Slovenia 2018 National Survey - Highlights", we presented the situation and activities in the field of nuclear energy in Slovenia in 2018. Leon Cizelj, as the President of the European Nuclear Education Network (ENEN) in the section on nuclear knowledge, presented: "Attracting & developing new nuclear talents: know-why or know-how? "

At the session, Dr. Joachim Knebel, Karlsruhe Institute of Technology (KIT, Germany), was elected President of the EAES for the next one-year term. The place and date of the next combined session in June 2020 in Norway was confirmed. The date of the next meeting of the Working Group in November 2019 in Riga (Latvia) was also determined.

During the session, the participants also visited the research reactor FRM II at the research center in Garching near Muenchen.

The meeting of the European Atomic Energy Society, held in Muenchen (Germany) from 1 to 5 June 2019, was organized by the German Karlsruhe Institute of Technology (KIT). We attended Prof.Dr. Leon Cizelj and dr. Ivo Kljenak.

ERCOFTAC (European Research Community on Flow, Turbulence and Combustion) brings together researchers from universities, research institutes and industries that deal with wide areas of fluid, turbulence and combustion research. Every two years ERCOFTAC organizes a workshop about Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES), which are the most accurate and demanding simulations of fluid flows.

In the area of ​​single-phase flows of fluids, a lot has been done in the recent years. Nevertheless, the development of numerical codes continues in the direction of greater precision of numerical methods and calculation optimization. At the same time, the constant increase in computational power improves the understanding of certain phenomena, especially in the field of heat transfer (eg, the very high Prandla number, convective jet cooling, etc.) , hydrodynamic instability (eg Rayleigh-Bénard convection, von Kármán's swirl paths, Kelvin-Helmoltz instability, etc.), the impact of surface treatment of walls on the flow of fluid, mechanical interaction of a liquid with a structure, etc. A large part of the research is currently focused on simulating two-phase flows that are more demanding and will play an important role in the development of accurate and reliable numerical methods in the coming decades, as well as a better understanding of the phenomena that we encounter every day both in nature and in various industrial processes, eg. from forecasting time and floods to improving the efficiency of heat transfer in nuclear power plants.

Meetings and workshops, held at the Carlos III University in Madrid between 5 and 7 June 2019, were attended by dr. Blaž Mikuž from the Jožef Stefan Institute for Reactor Engineering. The workshop was presented with a paper entitled "LES of a Taylor bubble and co-current turbulent pipe flow" in co-authorship with dr. E.M.A. Frederix and E.M.J. Komen from Nuclear Research and Consultancy Group (NRG), Netherlands.

The French energy company EDF (Électricité de France) annually organizes a meeting of users of the Code_Saturne and NEPTUNE_CFD Fluid Dynamics Programs. Code_Saturne is an open source program primarily intended for simulations of single-phase flows, while NEPTUNE_CFD is not freely accessible and is mainly designed for simulations of two-phase flows in nuclear engineering. EDF is one of the main developers of both programs. At R4 division, we are currently using NEPTUNE_CFD for simulations of heat and mass transfer in the vicinity of fragments of molten core.

About 200 participants from 25 organizations attended the meetings, most of them from EDF itself. At the meeting, the developers of both programs presented the innovations and repairs and the future of the development of programs. The major part of the meeting was aimed at presenting users of programs from various, mainly engineering fields, from the modeling of the flow in the nuclear reactor, to the study of air quality in settlements due to pollution along the roads. In addition to oral presentations, posters were also presented at the meeting.

The meeting, which took place on 7.5.2019 at EDF Lab Saclay near Paris, was attended by Matej Tekavčič, who presented a poster entitled "NEPTUNE_CFD simulations of heat transfer around a cylindrical core fragment in a sodium coolant."

The International Conference on Advances in Nuclear Power Plants (ICAPP 2019) was held between 12 and 15 May 2019 in Juan les Pins, France, organized by the French Nuclear Society. The main topic of ICAPP 2019 was to provide a key role for nuclear energy. 335 experts from 26 countries attended the meetings.

During the opening discussion and the 2 roundtables, the participants listened to the discussion on the state and future of the nuclear industry and the importance of research and nuclear energy for the decarbation of the energy sector. Three plenary sessions were organized to discuss new constructions, the future of the nuclear energy system, nuclear fuel and ensuring the sustainable use of nuclear energy. Additionally, 3 invited lecturers presented views on the evaluation of nuclear energy for the decarbonization of the energy sector and the use of nuclear power for space propulsion. In 6 technical sections and 1 poster section, 224 contributions in the following fields were presented: nuclear physics, thermo-hydraulics, operation and nuclear safety, fuel cycle, materials and technologies of thermal, rapid and modular reactors. In the framework of the conference, 42 Nuclear Socities from around the world signed the NICE future declaration, among other things, to double the public funds for research and development over the next 5 years.

The ICAPP 2019 Conference was attended by Rok Krpan and Mitja Uršič from the Reactor Engineering Division. At the conference they presented their work of the Scaling of experiments on the containment atmosphere mixing to nuclear power plant (Krpan, Tiselj, Kljenak) and the Investigation of the applicability of the MC3D code to vapor explosion in sodium (Uršič, Leskovar). In addition, Mitja Uršič, on behalf of the Slovenian Nuclear Society, participated in the signing of the NICE future declaration.

The CROSSING project (Crossing Borders and Scales - an interdisciplinary approach) establishes a strategic partnership between Helmholtz-Zentrum Dresden Rossendorf (HZDR) in Germany and the Jožef Stefan Institute (JSI). The purpose of the project is to extend the existing research activities to the sustainable and long-term cooperation of the two institutions. In addition to scientific topics, the project also includes the use and development of the research infrastructure of both organizations. Three scientific sub-projects range from the fields of living matter and material research, environmental chemistry, microbiological technologies and high-performance computing systems and computer simulations. Within the scope of the project, we are dealing primarily with the simulation and development of heat and mass transfer models in the two-phase, stratified gas and liquid streams at the Reactor Engineering Department (R4). In doing so, R4 cooperates with the related computer fluid dynamics section at HZDR, with which we have been individually involved in various European projects over the last ten years.

The purpose of the one-week working visit was to get a more detailed acquaintance and start work with the simulation tools they use on HZDR. These include, among other things, their own programs and extensions developed within the OpenFOAM tool, the GitLab source management system and the virtualization system at the Docker operating system level. During the visit, we also set up some initial examples of simulated flows, which will serve as the starting point for the development of models of heat and mass transfer in the continuation of the project.

ATLAS + is a four-year European project (June 1, 2017 - May 31, 2021) funded by the European Commission under Horizon 2020 (call 2017-2018). The project is aimed at developing advanced tools for assessing structural integrity for the safe and long-term operation of nuclear power plants. The project coordinator is the Technical Research Center of Finland (VTT).

The third session of the General Assembly marked the center of the project after two years of ongoing research activities. Leaders and representatives of (sub)work packages presented activities and status of results. The project continues on schedule without anticipated major delays in experimental and numerical part or results. In May 2019, a major milestone in WP1 (planning and performing the experiments) was achieved in the first large-scale test. The purpose of the test was to control the growth of the cracks through the wall in a ferrite nuclear tube under bending load. As anticipated, we successfully achieved limited growth of ductile cracks without catastrophic tube failure. In June, another milestone in work package 3 (growth of cracks due to mixing of the current) should be reached, in which the IJS is actively involved. These are the final results of the final computational fluid dynamics simulation (Large eddy simulations with conjugated heat transfer) in a flow mixer. The next General Assembly of the project will take place on May 27 and 28, 2020 in Miskolc, Hungary.

The third General Assembly of the ATLAS + project took place on 22-23 May in Manchester, United Kingdom, and was attended by Dr. Oriol Costa. The host institution was the University of Manchester, and representatives of the majority of partner institutions ATLAS + were present at the meeting.

CAMP (Code Applications and Maintenance Program) is the largest research program under the auspices of the U. S. NRC (Nuclear Regulatory Commission) since 1993. Within the framework of the CAMP research program, the development and exchange of experience regarding the RELAP5 and TRACE system programs, the PARCS neutron program and the SNAP graphical interface are under way. In the CAMP, based on an agreement with the U.S. NRC are involved administrative bodies, research organizations and industry representatives from more than 20 countries. The coordinator from SLovenia is the Jožef Stefan Institute (JSI). Nuclear Power Plant Krško and the Slovenian Nuclear Safety Administration are cooperating.

The CAMP Spring Meeting was split into a technical and programming part. In the technical part, the reports of some CAMP countries (Belgium, Czech Republic, Korea, Japan, Spain, Switzerland and Taiwan) were first presented and then status reports on the development of U.S. NRC programs followed: TRACE, PARCS, RELAP5 and SNAP. Finally, technical reports were presented (a total of 19). The IJS presented the contribution:

    Quantification of input uncertain parameters impact on station blackout in PWR (Andrej Prošek, Andrija Volkanovski).

Within the program part of the CAMP meeting, we discussed the need for further development of systems programs for the simulation of nuclear devices and proposals for contributions in kind, which are a requirement for all participants in the CAMP (for Slovenia one contribution annually, already proposed at the previous meeting for 2019). The new edition of the TRACE program is scheduled for autumn 2019.

This autumn CAMP meeting, which was held from 29-31. 5. 2019 at the Valencia University in Valencia, Spain, hosted the University of Valencia and the Spanish regulatory body for nuclear safety. The meeting was attended by 83 representatives from 15 countries, of which 44 particpants from the host country. From the JSI, Reactor Engineering Division, the meeting was attended by dr. Andrej Prošek.

From 24th to 26th of April, Oriol Costa Garrido (IJS representative), Iztok Tiselj (representative of the University of Ljubljana) and Leon Cizelj (president of ENEN - European Nuclear Education Network and representative of the JSI) attended the ENEN + project's working meeting. The three-year project ENEN +, funded by the European Commission as part of the Horizon 2020 program, aimed at encouraging the flow of young professionals in the fields of nuclear technology, medical physics and radiation protection. The bulk of the project's resources is devoted to the fund, where students can receive financial support for education abroad. Approximately two thirds of funds intended for student hosting are distributed after half of the project.

During the meeting, we discussed mechanisms to present nuclear technology to the widest possible range of secondary and higher education students, as well as working reports that should be prepared after the first 18 months of the project. Although the preparation of the planned work reports is somewhat behind schedule, the assessment is that the activities within the project take place approximately according to the plan.

In 2010, the International Atomic Energy Agency (IAEA) set up a panel of technical support ogranizations (TSOs) to promote cooperation and exchange of information. The basis for the work group is the document TECDOC-1835 (Technical and Scientific Support Organizations Providing Support to Regulatory Functions). In 2012, a Steering Committee was established, which is concerned with the implementation of the program of the group.

The fourteenth meeting of the Steering Committee was held by the IAEA in Vienna, Austria, from 11 to 12 April 2019. The meeting had nine sections: (1) opening, (2) feedback on the TSO 2018 conference in Brussels, (3) work TSO in China, (4) the TSO initiative to support technical and research capacity in administrative functions, (5) information on the International Conference "Effective Nuclear and Radiation Safety Regulatory Systems", (6) presentation of the IAEA Information Portal, (7) other, (8) presentation of the assembly of administrative bodies; and (9) conclusion. The main points of the meeting of the Committee were:

•     The choir is preparing a pilot workshop on the establishment of a TSO in the Republic of South Africa.
•     The choir develops a tool for self-evaluation of TSO capacities.
•     Every 4 years the choir prepares a conference. At the last conference in 2018, the need for effective and sustainable research, education and training was also expressed.
•     The NSC, the carrier of the TSO in China, was introduced. A part of the NSC is also a large R&D center.
•     The IAEA has set up a portal to more effectively review their material (https://nucleus-apps.iaea.org/nss-oui).

MELCOR software is one of the computer softwares used to independently verify the analysis of severe accidents. The MELCOR program can be obtained by participating in the U.S. International Research Program. NRC CSARP (Cooperative Severe Accident Research Program). Slovenia has been a member of the CSARP program since 2015. Within the framework of the CSARP research program, regional annual meetings for European users of the MELCOR program (EMUG - European MELCOR User Group) have been held for several years.

The eleventh meeting of European users of the MELCOR and MACCS programs was held by the Paul Scherrer Institute (PSI) in Brugg-Windisch, Switzerland, from April 3 to 5, 2019. On the first day of the meeting was a workshop for users of the MELCOR program. The second and part of the third day there was a meeting of MELCOR users. Mostly of the third day was dedicated to the meeting of MACCS users.

The meeting of MELCOR users this year was divided into three sections: (i) introductory presentations, (ii) applications for light water reactors, and (iii) applications for advanced reactors, fusion reactors and spent fuel pools. During the sections, the developers and users of the MELCOR program presented their activities. Dr. Mitja Uršič held the presentation:

    Leskovar, Uršič: Analysis of Severe Accident in Safety Upgraded Krško NPP with MELCOR 2.2.

Meetings of MELCOR users were attended by dr. Mitja Uršič from the Reactor Engineering Division from the Jožef Stefan Institute. It was attended by 53 users and developers of the MELCOR / MACCS program from 14 European countries and the USA.

European fusion research under the Horizon 2020 framework and the EURATOM treaty is joined by a targeted 7-year (2014-2020) fusion program EUROfusion. The European fusion program is aimed at research in support of the ITER fusion reactor and the long-term, development and realization of the demonstration fusion power plant. The EUROfusion program is implemented by a consortium of EU Member States' fusion research units (a total of 30), where the Jožef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The leading partner in the consortium is Max Planck Institute of Plasma Physics in Garching, Germany. The decision-making body of the consortium is the General Assembly.

In days 16.4. and 17..2019, the 25th General Meeting of EUROfusion took place in Frascati. The meeting was organized at the ENEA Research Center (Agenzia nazionale per le nuove technologie, l'energia e lo sviluppo economico sostenibile). In addition to the ongoing issues for the implementation of the fusion program (substantive and financial aspect), most of the time the meeting was dedicated to the presentation of the DTT project (Divertor Tokamak Test facility). DTT is a new tokamak fusion device, funded largely by the Italian government through the European Structural Funds. The DTT is expected to be built by 2025 at the Frascati Research Center. The main purpose of the device is to test different configurations of the diverter and the magnetic restraint, so it will be built very flexibly. The main goal is to support the development of the DEMO power plant and  find a plasma operation regime without unwanted plasma breaks, which are not allowed in the DEMO reactor. At the meeting, the heads of individual sections of the DTT project presented the course and project management, the technical characteristics of the plant and the plan for carrying out physical experiments on the device. The DTT was designed with the help of experts from the EUROfusion program in accordance with the needs of the DEMO power plant development program and will also be part of the infrastructure of future research programs.

The General Meeting of EUROfusion was attended by Dr. Boštjan Končar from the Department of Reactor Engineering, JSI.

NUGENIA (Nuclear Generation II & III Association) is an organization that unites (in particular) European stakeholders in the field of nuclear energy: research and technical security organizations, and nuclear power plant regulators and industry. NUGENIA was officially established in 2011. The main purpose of the organization is to direct and coordinate research in the field of nuclear energy.

As every year from 2014 onwards, NUGENIA was also organized this year. The forum, which is an opportunity to negotiate cooperation in research and to propose joint European projects, is usually attended by representatives of member organizations. At the NUGENIA forum there were more than 250 registered participants this time, which testifies to the importance of this event.

On the first day of the Forum, the themes in the field of nuclear energy dealing with a wider circle of stakeholders were discussed at plenary sessions:

• the role of nuclear energy in the energy mix and climate change,
• improving safety in nuclear power plants,
• earthquake control in nuclear power plants,
• digital transition in nuclear power plants,
• the competitiveness of nuclear energy and the role of innovation,
• modernization of nuclear power plants and instrumentation and control,
• research for the decommissioning of nuclear power plants.

 During the second day, the forum was divided into the following six separate technical sections:

• Improved safety
• Digital transition
• Dismantling
• Hazards & environment
• Component manufacturing
• Innovation & competitiveness of nuclear

During the third day of the Forum, the chairmen of individual technical sections at the plenary session gave a substantive review and synthesis of the presentation of the previous day. In addition, some general presentations on topics concerning a wider circle of stakeholders were again:

• the contribution of the International Atomic Energy Agency for Innovation in Advanced Water-Cooled Reactors,
• nuclear competitiveness,
• European nuclear policy,
• Euratom research programs.

In the afternoon of the third day, members of the technical field TA2 "Severe accidents" held separate meeting where they reviewed the state of the area and discussed the continuation of the research.

The Forum NUGENIA, held from 13 to 15 March 2019 in Paris, France, was attended by the head of the technical subsection NUGENIA TA2.3 "Containment" dr. Ivo Kljenak from the Reactor Engineering Division IJS.

NARSIS is a four-year European project of the Horizon 2020 Framework Program, the main objectives of which are to fill identified weaknesses in security analysis of external threats and propose recommendations for future legislation. The first three work packages are of a research nature, and the fourth and fifth are applicative in nature. The Jožef Stefan Institute, Reactor Engineering Division (IJS, R-4) participates in the first four work packages and in the sixth. The first work package is designed to characterize physical threats due to various external hazards and scenarios. The second work package is designed to assess the main critical components of the nuclear power plant. The third work package is intended for common risk and safety analyzes, and the fourth is a comparison of different safety approaches for safety assessment in the case of the actual reactor. The fifth work package is a tool to support the handling of serious accidents, and the sixth to disseminate the results achieved in the project.

The meeting was divided in two parts. First, a General Assembly was held where representatives of the participating organizations were informed by the coordinator after the quorum check on the current status of the project. In the second part, a plenary session took place, where the heads of work packages presented the work done in individual sections. On the last day, the Coordinator reported on the upcoming financial reporting to the European Commission. For the international workshop NARSIS, which will be held in Warsaw in September 2019, we prepared the lecture titles related to the content of the project. We also agreed on the next plenary meeting, which will be held immediately after the workshop and hosted by the University of Warsaw.

The NARSIS meeting, which took place from 19th to 21st March 2019 in Delft (Netherlands), was hosted by the Delft Technical University (TU Delft). It was attended by dr. Andrija Volkanovski and dr. Andrej Prošek.

ERMSAR (European Review Meeting on Severe Accident Research) are regular conferences on the topic of severe accident research at nuclear power plants. The series began with the first conference in 2005 in Aix-en-Provence (France). The first five conferences were organized in the framework of the SARNET (Severe Accident Research Network of Excellence), which was held under the 6th Framework Program of the European Commission (FP EC) from 2004 to 2008 and in the framework of the 7th FP EC 2009-2013 After the end of the  financing of the SARNET network, the conference is organized independently, but is informally linked to the NUGENIA (Nuclear Generation II & III Association) association.

This year's ERMSAR 2019 conference, organized by UJV Řež from the Czech Republic, was already the ninth in a row. The conference was attended by 184 participants, and it presented six plenary presentations and 64 papers. The following topics were discussed at the conference (the numbers in brackets represent the number of papers presented):

- In-vessel corium and debris coolability (18)
- Severe accident scenarios (15)
- Source term issues (9)
- Ex-vessel corium and debris coolability (7)
- Severe accident modeling and code development (6)
- Containment behavior, including H2 explosion risk (5)
- Emergency preparedness and impact on environment (4)

I. Kljenak participated in the conference as a member of the program committee as chair of the section "Containment behavior, including H2 explosion risk" and presented the report: Simulation of experiment on light gas layer erosion and small-scale MCTHBF containment experimental facility (R. Krpan, I. Kljenak, Houjun Gong, Ying Wang, Yuanfeng Zan, Pengzhou Li, E. Studer, A. Bentaib, N. Méchitoua), created as a result of the IJS collaboration, the Nuclear Power Institute of China (China), the Commissariat à l ' Energie Atomique et aux Energies Alternatives, Institute of Radioprotection and the Süret Nucléaire in Electricité de France (all France).

M.Leskovar presented the paper: Analysis of steam explosion duration in stratified configuration (M. Leskovar, V. Centrih, M. Uršič, J. Kokalj).

The next ERMSAR conference will be organized by the Karlsruhe Institute of Technology in Karlsruhe (Germany) in 2021, and for the year 2023 the organization was offered by the IJS in Slovenia.

The 9th Conference on Severe Accident Research ERMSAR 2019 (European Review Meeting on Severe Accident Research), held from 18 to 20 March 2019 in Prague (Czech Republic), was attended by dr. Ivo Kljenak and dr. Matjaž Leskovar from Reactor Engineering Division.

European fusion research under Horizon2020 brings together the targeted fusion program EUROfusion, under the auspices of the EURATOM Treaty. The EU's core objectives of fusion research are related to research in support of the ITER fusion reactor and, in the long term, the implementation of the demonstration fusion power plant DEMO. The EUROfusion program is implemented by a consortium of fusion research units of EU Member States where the Jožef Stefan Institute acts as a Slovenian coordinator and partner in the consortium.

The ITER external heating system - neutral beam injection system - will have to be tested before the ITER operation on the NBTF (Neutral Beam Test Facility), located in Padova, Italy. An experimental device, which will be a complete replica of the injector neutral injection system, will allow scientists to investigate complex physical and technological problems and test the concepts of operation before the neutral beam system is installed on ITER. In all aspects it is by far the largest such device ever built in the world. The NBTF test center includes two devices - SPIDER, negative ion source and MITICA, high-voltage injection of neutral rays. SPIDER is already built and MITICA will be completed in the next two years. The NBTF in Padova was built with the help of the European Agency for ITER (F4E), Japan, India and Italy. EUROfusion works as a partner in the provision of human resources in the design and operation of the device.

In the days of 25 to 26.3. In 2019, in Padova, at the Consorzio RFX institute, a working meeting was held related to the design and implementation of experiments on the NBTF. The NBTF Center and the long-term goals of operating and conducting experiments were presented at the meeting. The representative of ITER presented the importance of the test facility in Padova, while the leader of EUROfusion presented how and to what extent the European laboratories will be able to contribute to the operation of the NBTF. The envisaged level of integration between 2020 and 2030 co-financed by EUROfusion is 14 man years each year. There are many opportunities in which JSI can participate. The meeting was attended by dr. Boštjan Končar from the Reactor Engineering Division, JSI.

European fusion research under Horizon 2020 connects the targeted 5-year (2014-2018) fusion program EUROfusion, under the auspices of the EURATOM Treaty. Due to the 7-year period of the Horizon 2020, the program has been extended for two years by 2020, with the same annual funding volume. The EU's main objectives of fusion research are related to research in support of the ITER fusion reactor and, in the long term, the implementation of the demonstration fusion power plant DEMO. The EUROfusion program is implemented by a consortium of EU Member States' fusion research units (a total of 30), where Jožef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The leading partner in the consortium is the Institute of Plasma Physics (IPP), Germany.

In the days of 27th to 28th February 2019 in Espoo, Finland, a working meeting and a workshop on the perspective of the development of the DEMO reactor took place. At the meeting, the current status of the development of the DEMO reactor was presented, and above all, we focused on open topics that will need to be given greater emphasis in the 9th Framework Program for European Fusion Research. Such an area is, for example, technological and industrial development of the fusion fuel cycle (from the technology of purified lithium production to the process of tritium production in fertile lining). We discussed the materials of the first reactor wall, the technological capabilities of industrial production of low-activation steel, which transmits neutron damage above 20 dpa. On the second day of the meeting, good synergies of research and industry in the field of fusion were presented. A representative of the European Commission highlighted several areas of development of new technologies and patents that emerged from fusion and are now present in various fields of application (eg nuclear magnetic resonance). A special section was also devoted to the scenario and strategy of plasma control, since high plasma instability in the fusion power plant will not be allowed. The meeting was attended by dr. Boštjan Končar and dr. Matjaz Leskovar from the Reactor Engineering Department of the JSI.

On the 17th of December 2018, as a representative of the University of Ljubljana, prof. dr. Iztok Tiselj attended the first meeting of the partners of the joint study program SARENA. SARENA master's program (MSc in SAfe and REliable Nuclear Applications) is coordinated by IMT Atlantique University. Within the program also cooperate Lappeenranta Univ. of Technology, Madrid Technical University and the University of Ljubljana (Faculty of Mathematics and Physics). The progmram is co-financed by the EU through the Erasmus + program. In the program, 4 generations of 15 students will graduate with the degrees from two of the four participating universities.

Year 2018/19 is a preparatory year for the SARENA program. The first generation will enroll in the autumn of 2019. During the work meeting, the website of the program was opened, which will collect applications by the end of March 2019. This is followed by a selection of students who will be accepted for study and those who will receive EU scholarships.

European fusion research under Horizon 2020 brings together the targeted 5-year (2014-2018) fusion program EUROfusion, under the auspices of the EURATOM Treaty. Due to the 7-year period of the Horizon 2020, the program has been extended for two years by 2020, with the same annual funding. The EU's main objectives of fusion research are related to research in support of the ITER fusion reactor and, in the long term, the implementation of the demonstration fusion power plant. The EUROfusion program is implemented by a consortium of EU Member States' fusion research units (almost 30), where Jožef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The leading partner in the consortium is the Institute of Plasma Physics (IPP), Germany. The decision-making body of the consortium is the General Assembly.

On 17.12. and 18.12.2018, the 24th General Meeting of EUROfusion took place in Gothenburg, Sweden. The meeting was organized at the Chalmers Technical University. At the general meeting, the coordinator presented the status of program implementation and the content program for the years 2019 and 2020, which was also confirmed by the Assembly. Also at this meeting, an essential part of the discussion was devoted to the preparation of the fusion program for the 9th EURATOM framework program. Above all, we have adopted common positions regarding the new way of implementing and managing the program, which will be simpler in the forthcoming framework program.

The General Meeting of EUROfusion was attended by Dr. Boštjan Končar from the Reactor Engineering Division from JSI.

CAMP (Code Applications and Maintenance Program) is a research program under the auspices of the U.S. Nuclear Regulatory Commission (U.S. NRC) since 1993.
Within the framework of the CAMP research program, the development and exchange of experience in the field of computer programs RELAP5 and TRACE, the PARCS neutron program and the SNAP graphical interface are under way. In the CAMP, based on an agreement with the U.S. NRC, currently participates more than 20 countries. From Slovenia the Jožef Stefan Institute (JSI) is the coordinator (in addition to IJS, the Nuclear Power Plant Krško and the Slovenian Nuclear Safety Administration also participate).

The CAMP Fall Meeting was divided into two parts, technical and program. In the technical part, the U.S. NRC presented the development status of U.S. NRC computer programs TRACE, RELAP5, PARCS and SNAP. The reports of the four CAMP countries (Croatia, South Korea, Slovenia and Sweden) followed. The IJS presented the contribution:

    "Status of CAMP Activities in Slovenia" by Andrej Prošek.

Technical reports were presented in total 10. They were related to the use of computer programs RELAP5, TRACE and PARCS. Within the program part of the CAMP meeting, we discussed the need for further development of system programs for the simulation of nuclear devices and proposals for contributions in kind. The IJS proposed a contribution in kind for the year 2019 entitled "LOCAs with loss of an active emergency cooling system simulated by RELAP5" approved by the Technical Program Committee.

This year's CAMP fall meeting, held from 11-13 December 2018 at the headquarters of the U.S. NRC (Three White Flint North Facility), North Bethesda, Maryland, USA, was organized by the U.S. NRC. The meetings was attended by 47 representatives from 16 countries, one at a distance and 17 from the host country. From the JSI, Reactor Engineering Department, the meeting was attended by dr. Andrej Prošek.

The European Commission, in the framework of the SAFEST project (Severe Accident Facilities for Europe Safety Targets), co-finances the selected experiments in the area of ​​severe accidents in nuclear power plants at different experimental facilities in Europe. The SAFEST project  includes also the Steam Explosion Stratified (SES) facility, located at the Royal Institute of Technology (KTH) in Sweden, and is intended to investigate steam explosions in stratified conditions. A steam explosion can occur during a severe accident in a nuclear power plant when a molten corrium comes in contact with the cooling water.

Under the joint leadership of dr. Matjaž Leskovar from the Jožef Stefan Institute (JSI) Reactor Engineering Divison and dr. Erik De Malmazet of the Électricité de France (EDF) from France a group of experts from the IJS, EDF, the Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA) and the Institute of Radioprotection et de Sûreté Nucléaire (IRSN) from France and the Institute for Nuclear Technology and Energy Systems (IKE) from Germany developed an experiment on a steam explosion on the SES device, which was successfully executed in May 2016.

At the end of the SAFEST project, the CEA organized the final SAFEST seminar on experimental research in the field of severe accidents, which was held from 10-12 December 2018 in Cadarache, France, with about 40 participants. The seminar consisted of four sections: General Topics, Problem of melted corium in the reactor vessel, Problem of melted corium outside the reactor vessel, Other topics. At the seminar participants presented the results of the project and plans for the future.

The seminar was attended by dr. Matjaz Leskovar from the IJS who had a presentation with the title: E. De Malmazet (EDF), M. Leskovar (IJS) et al., Stratified Steam Explosion Phenomena: SAFEST SES-S1 test results and analysis.

European Atomic Energy Society Working Group Meeting

Lisbon, Portugal, 28. 11. - 1. 12. 2018

The European Atomic Energy Society (EAES) is an organization founded in 1954 and brings together European research organizations in the field of nuclear energy. The current most important function of the EAES is the exchange of information on nuclear research guidelines in the home countries of organizations. The EAES consists of the Council (member from the IJS is prof. dr. Leon Cizelj) and the Working Group (member from the IJS is doc. dr. Ivo Kljenak). The working group also has also a separated two-day meeting each year, usually in November or December.

On the first day of the Working Group meeting, mainly the next Combined meeting of the Council and the Working Group was prepared, which will be held from 1 to 5 June 2019 in Munich (Germany), organized by the Karlsruhe Institute of Technology. At that session the following topics will be discussed:

    experience in the decommissioning of the research reactors;

    the use of the nuclear technology in the medicine;

    how to maintain knowledge in the field of nuclear energy in Europe.

On the second day of the meeting, we visited a laboratory of the following units at the IST Tecnico Lisboa Institute, a member of the University of Lisbon:

    Institute of Systems and Robotics

    Institute for Plasma and Nuclear Fusion

At the meeting we also discussed the issue of countries from which there are no EAES member organizations. We have found that it is particularly important to convince representatives of organizations to attend EAES meetings at least once. After the first participation at the meeting, representatives of organizations discover the benefits of EAES membership and regular meetings attendance.

The meeting of the European Atomic Energy Society Working Group, held in Lisbon, Portugal, on 29th and 30^th of November 2018, was organized by the Portuguese Institute IST Tecnico Lisboa. It was attended by dr. Ivo Kljenak from the IJS Reactor Engineering Divison.

16th Multiphase Flow Conference & Short Course, 13.-16.11.2018, HZDR, Dresden

Knowing the multiphase flows of fluids is important in various fields, such as electricity generation, nuclear reactor technology, food processing, and chemical, automotive and aviation industries. The purpose of the 16th conference and the short course on the multiphase flow is to bring together experts in the field of measurement and modelling of multiphase flows, as well as promoting the discussion and exchange of knowledge about the multiphase flow. The short course, which took place the first and half of the second day of the meeting, dealt with both the basics of multiphase flows modelling as well as a general overview of experimental methods. There was also a tour of the experimental laboratories for studying the multiphase flows of the HZDR Institute (Helmholtz Zentrum Dresden Rossendorf), where the meeting took place.

The conference and short course, which took place from 13th to 16th November 2018 in the organization of the HZDR Institute in Dresden, was attended by Matej Tekavčič, who at the conference presented a paper entitled "Three-dimensional simulations of liquid waves and isothermal vertical churn flow with interFoam «.

Prof. dr. Iztok Tiselj, the first Slovenian nuclear expert to hold a lecture at the American Nuclear Society

American Nuclear Society Winter Meeting 2018 lasted from 11th to 15^th of November 2018. Three special conferences were held at the General Conference: "Embedded Topical Meeting: Advances in Thermal Hydraulics", "Advances in Nuclear Nonproliferation Technology and Policy Conference" and "Technology of Fusion Energy".

The general part of the conference was marked by the efforts to revive US nuclear energy, where most of the speakers, as the best opportunity, see small modular reactors. In the field of nuclear thermal hydraulics most of the presentations was about computationally complex three-dimensional simulations of single phase and two-phase flows occurring in nuclear reactors.

Prof. dr. Iztok Tiselj from the Jožef Stefan Reactor Engineering Division and Head of the Department of Nuclear Engineering at the Faculty of Mathematics and Physics at the University of Ljubljana held on November 15th, a one-hour lecture within the "Advances in Thermal Hydraulics" meeting. The lecture entitled "Direct Numerical Simulation and Wall-Resolved Large Eddy Simulation in Nuclear Thermal Hydraulics" was co-authored by dr. Cedric Flageul, associate of the research division of the French energy giant EDF (“Electricite de France”) who was post-doc in the Reactor Engineering Division and the doctoral student Jure Oder. The topic of the lecture were the most detailed physical models and the most accurate numerical methods that we use today for turbulent flow simulations, namely the use of direct numerical simulation (DNS) and large eddy simulation (LES) in the field of nuclear engineering. The extraordinary accuracy of these models/methods also requires a lot of computational power, and therefore their use in industry is today still very rare. This two methods are besides experiments today a key method for researching the basic mechanisms of turbulent heat and mass transfer.

 The mentioned research is a part of the research project started this year at the of Reactor Engineering DIvision, where we will accurately predict the transfer of heat in annular geometry with these calculation methods and experiments. Three-quarters of the funds for the project are contributed by the ARRS, and a quarter by the Krško Nuclear Power Plant. We thank everyone for the support. Prof. Tiselj is the first Slovenian nuclear expert to hold a lecture at the American Nuclear Society.

The proposed research program "Fusion Technologies" was selected for funding in the public tender of the Slovenian Research Agency. The research that is carried out since 2005 by the researchers associated within the Slovenian Fusion Association, is focused on the development of fusion reactor components and systems, structural materials, plasma-wall interaction in fusion devices, neutron transport studies and modelling of fusion-relevant plasma. The research is closely linked to the EUROFusion program (Horizon 2020) aimed at supporting the ITER reactor and the development of the demonstration fusion power plant DEMO. The program "Fusion Technologies", which will be led by dr. Boštjan Končar from the Reactor Engineering Division of JSI, is highly interdisciplinary and includes several departments of JSI (R4, F2, F4, F8 in K7), Faculty of Mechanical Engineering and the Faculty of Electrical Engineering from University of Ljubljana.

ENEN and NEA signed MOU to foster nuclear education and training

On 31st October 2018 the European Nuclear Education Network (ENEN) and the Nuclear Energy Agency (NEA) have signed a Memorandum of Understanding (MoU) to co-operate in the field of nuclear education, training and knowledge transfer – an increasingly important concern for NEA member countries. The MoU aims to advance the ENEN and NEA's common aim of improving existing educational activities in the nuclear field, and maintaining the capability and expertise necessary to ensure the continued safe and efficient use of nuclear technology. ENEN and the NEA will cultivate joint efforts to develop education tools, approaches, methods and opportunities that will help foster the development of the next generation of nuclear scientists.

The Memorandum of Understandingwas signed by Mr. William D. Magwood, Director-General of the OED-NEA, and Prof. Leon Cizelj, President of ENEN.

(source: https://www.oecd-nea.org/)

The Steering Committee is the highest committee advising the Director General of the OECD / NEA (Nuclear Energy Agency). It consists of senior representatives of governments of OECD / NEA member countries, often directors of nuclear regulatory authorities.

The Steering Committee organized a discussion on the challenges and opportunities in personnel development that are necessary for the safe management and development of nuclear technologies. This topic has been on the agenda of nuclear decision makers for at least two decades. Unfortunately, despite considerable efforts at this time, there was no significant progress. That is why the Steering Committee invited four experts (ENEN, UK, USA and Korea) to give an assessment of the situation and possible measures for urgent improvements in the near future.

The discussions were attended by Prof. dr. Leon Cizelj, Head of the Reactor Engineering Division.

The EURATOM Program Committee is composed of representatives of all the Member States of the European Community. The Committee advises and directs the European Commission services in the preparation of research project tenders in the field of nuclear fission.

The meeting was mainly aimed at coordinating the program of work of project calls in 2019. The relatively lively discussion of committee members brought a greater number of requirements to supplement the program. The expert services will prepare the program's amendments, which will then be discussed and presumably also accepted by the Program Committee at its next meeting on 5. 11. 2018.

The fission part of the EURATOM Program Committee meeting was attended by prof. dr. Leon Cizelj, Head of the Reactor Engineering Division.

The association of 18 German research centers, the »Helmholtz Association«, seeks to strengthen joint research in Europe - especially in Eastern, Central and Southern Europe - through its new funding program, the »Helmholtz European Partnering« (HEP). Institutional partnerships with Helmholtz centers in targeted research areas should contribute to the launch of new projects and the sustainable development of local research systems. In the first HEP call, out of 12 applications, three projects were selected, including the CROSSING project (Crossing borders and scales - an interdisciplinary approach), which establishes a strategic partnership between Helmholtz-Zentrum Dresden Rossendorf (HZDR) in Germany and the Jožef Stefan Institute (JSI ) in Slovenia. The project is three-year, with the option of renewal for two years, with an annual allocation of 250.000 €.

On the basis of individual cooperation, especially in the framework of European projects in the last ten years, the CROSSING project aims at extending existing research activities to a sustainable and long-term strategic partnership between the two institutions. In addition to scientific topics, the project also includes the use and development of the research infrastructure of both organizations. Three scientific workpackages range from the fields of live matter and material research, environmental chemistry, microbiological technologies and high-performance computing systems and computer simulations: WP1 - correlative microscopy, WP2 - nanoparticles in the earth, WP3 - high performance computational simulations of two-phase systems and machine learning. The fourth workpackage is infrastructure one, WP4 - networking and infrastructure development. The projects are highly interdisciplinary, as they connect different research disciplines and different size systems of treatment, from atomic level to macroscopic world.

In days 25.10. and 26.10.2018 an initial meeting of the CROSSING project took place in Dresden, attended by a wider JSI delegation, led by the director and representatives of various departments of the JSI, participating in the project. At the meeting, we discussed and defined the financial, staffing and content frameworks of the project, which will start on January 1, 2019. On the first day of the meeting, we also visited the research infrastructure of the HZDR - Ion Beam Center (IBC), TOPFLOW thermohydraulic center and the computer center for high-performance computing. The second day of the meeting was aimed at presenting five candidates for the young leader of two of the three research workpackages. The young leader of the WP1 dr. Rok Podlipec from the F5, JSI and as the young leader of the WP3, the HZDR candidate was selected.

From the Reactor Engineering Division, JSI, the CROSSING meeting was attended by dr. Boštjan Končar.

The International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operation and Safety (NUTHOS) has been in place for more than 20 years, and so far in the countries of North-East Asia: PR China (including Taiwan), Japan and the Republic of Korea. The conference focuses primarily on thermo-hydraulics, that is, the flow of liquids and the transfer of heat and mass in nuclear power plants.

The presentations on this year's NUTHOS conference focused on the following areas:

- Thermo-hydraulics of the containment,

- advanced reactors,

- reactors with liquid metals,

- experimental thermo-hydraulics,

- computational fluid dynamics,

- severe accidents,

- two-phase flows and heat transfer,

- power plant management,

- Approaches on several scales and with different physics.

Participation at the conference was interesting mainly due to the mass participation of Chinese researchers and experts. China is currently the state in which the most of new nuclear power plants are being build and where research in the field of nuclear energy is the most intensive and covers a broad area.

My overall assessment of the content of the papers is that the prediction of phenomena in experimental installations and systems of nuclear power plants in which fluid flow, heat transfer and mass transfer is present, and which is based on numerical solving of the basic equations and additional constitutional relations is still not satisfactory, although this would be expected due to the development of computer technology. In particular, this target is remote for nuclear systems in the right power plants. For this reason, it is necessary to continue this type of research, which takes place at the JSI within the framework of European projects and programs and ARRS projects. In this regard, one should not rely solely on the further development of computer technology, but it is necessary to develop physical models based on the phenomenological understanding of the phenomena under consideration.

At the conference I presented the paper: "Experiment on light gas layer erosion and a small-scale MCTHBF containment experimental facility" by H.Gong, Y. Wang, Y. Zan, P.Li (all Nuclear Power Institute of China, China) I. Kljenak (IJS), E.Studer (CEA, France), A.Bentaib (IRSN, France) and N.Mechitoua (EdF, France).

On the last day of the conference, I attended a professional excursion to the Hayiang nuclear power plant, where are planed six units of nuclear reactors Westinghouse AP1000. The first unit is already connected to the grid, while the second unit is scheduled for the next year.

The NUTHOS-12 Conference (12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operation and Safety), which took place from 14 to 18 October 2018 in Qingdaou (PR China), was attended by dr. Ivo Kljenak from the Reactor Engineering Division, IJS.

Expert meeting on OECD / NEA ROSAU project proposal, OECD / NEA, Paris, France, 20. - 21. 9. 2018

The Organisation for Economic Co-operation and Development (OECD) brings together 34 Member States and is known as the organization of elite economies. Several specialized agencies operate within the OECD, including the Nuclear Energy Agency (NEA). The mission of the OECD/NEA is to support Member States through international cooperation in maintaining and further developing the scientific, technical and legal basis for the safe, environmentally friendly and economical use of nuclear energy for peaceful purposes. NEA activities comprise several areas. In the field of nuclear safety and governance, the Committee on Safety of Nuclear Installations (CSNI) operates within the framework of which several working groups are operating. The main task of the Working Group on Analysis and Management of Accidents - WGAMA - is to improve the understanding of physical processes and addresses the security concerns of existing and advanced reactors.

Argonne National Lab (ANL) from the United States at the CSNI meeting in December 2017 presented a proposal for the OECD/NEA ROSAU (Reduction of Severe Accident Uncertainties) project. CSNI has approved the implementation of a WGAMA Expert Meeting, which would bring together the content of the project and verify the interest of individual countries to participate in the project. The expert meeting was held from 20. -21. 9. 2018 at the OECD/NEA in Paris. At the meeting, ANL presented the background of the proposed 5-year ROSAU project in the amount of USD 9.9 million, the content of the project, proposed experiments, timetable and costs per year. The project encompasses topic spreading and cooling of the melt of the core, which in the case of a severe accident in a nuclear power plant and the failure of the reactor vessel flows into the flooded reactor cavity is divided into two experimental sets:

•     Experiments (6) underwater melt spreading,
•     Experiments (5) on the molten core cooling and molten core concrete interaction.

Accompanying analytical activities are also foreseen. OECD/NEA presented the standard rules of cost sharing such joint projects: 50% of the costs are covered by the experiments conducting country, the remaining costs shall be covered by the participating countries in the project in proportion to the gross domestic product of the country, but not less than 1,5% and not more than 10% . The contribution of Slovenia (1.5%) would thus be 150,000 USD. Exceptionally, countries may also agree to a different cost sharing, for example, enable the country to participate with an appropriate contribution in kind. The following countries presented their interest in participating in the project (covering project costs): USA, Japan, the Czech Republic, Sweden, Belgium, China, France, Spain, Germany and Korea. Previously, the following countries expressed their interest, but did not attend the meetings: United Arab Emirates, Russia, Canada. The OECD/NEA will prepare a cooperation agreement and will send it to countries willing to cover the costs of the project. The initial meeting of the ROSAU project is expected to be from 29. - 30. 1. 2019 at the OECD / NEA in Paris.

The meeting of experts on the proposal of the OECD/NEA ROSAU project was attended by dr. Matjaž Leskovar from the Reactor Engineering Division (R4) and he actively participated in expert discussions. He explained that the IJS R4 is interested in participating in the project, but that it can contribute only with analytical activities.

The Canadian Nuclear Safety Commission (CNSC) and Canadian Nuclear Laboratories (CNN) jointly organized the "2018 International Severe Accident Management Conference" on the initiative of the Working Group on Analysis and Management of Accidents (WGAMA), which works in the framework of the Committee on Safety of Nuclear Installations (CSNI) at Nuclear Energy Agency (NEA), Organization for Economic Co-operation and Development (OECD). At the conference, which took place in Ottawa, Canada, from 15-18. 10. 2018 on the premises of the old town hall, participated around 200 participants from 22 countries. The conference discussed the following topics:

• Post-Fukushima improvements of the requirements, principles, strategies and procedures for severe accidents management,
• Equipment for severe accidents management,
• Human factors in the accidents conditions,
• The use of research results and development to enhance the effectiveness of accidents management.

The main conclusion of the conference is that human error contributes significantly to the development of a severe accident, and that it is therefore necessary to improve the participation of nuclear professionals and experts in the field of social sciences.

The conference was attended by dr. Matjaž Leskovar from the Reactor Engineering Division (R4) and presented a presentation entitled: M. Leskovar, M. Uršič, Analysis of the Krško NPP Safety Upgrade Influence on SAMGs with MELCOR, which was accepted with interest.

International IAEA Conference for TSOs, Brussels, Belgium, 15-18. 10. 2018

International Conference for TSOs for nuclear safety with the full name »International Conference on Challenges Faced by Technical and Scientific Support Organizations (TSOs) in Enhancing Nuclear Safety and Security: Ensuring Effective and Sustainable Expertise«  was in its fourth (4th) execution organized under the auspices of the IAEA in cooperation with the Belgian Bel V. The conference is devoted to presenting the importance of scientific and technical capacity support in the decisions of regulators, which contribute to the improvement of nuclear and radiation safety and innovative proposals for the development, maintenance and enhancement of such capacities.

Several other activities took place simultaneously during the conference. A presentation of the authorized experts, members of ETSON, was held, where IJS was represented by Tadej Holler. Traditionally, the conference held the ETSON award event, at which Tadej Holler participated with contribution entitled "Temperature Conditions effect on hydrogen-air flame propagation and the ENACCEF2 experimental facility," co-authored with colleagues from IRSN, CNRS / IRSN and LEI. At the same time, the general assembly and the board of directors of the ETSON Association took place, which was attended by prof. dr. Leon Cizelj.

The conference, which was attended by 290 participants was co-organized by the IAEA and Bel V in Brussels, Belgium, from 15. to 18. October 2018. From the Reactor Engineering Department of Institute "Jožef Stefan" the conference was attended by Tadej Holler and the head of the department prof. dr. Leon Cizelj.

Initial ASCOM project meeting and 8th meeting of ASTEC Users Club, 7. - 11. October 2018, Aix-en-Provence, France

ASTEC is a system computer code that enables the simulation of all phases of a potential severe accident in a light-water nuclear power plant, from the occurrence of a loss-of-coolant accident, through the degradation and melting of the reactor core, up to the behaviour of hydrogen and fission products in the containment. The program is developed by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) from France. At the JSI, the ASTEC program was used to perform a number of simulations since 2005, mainly in the framework of the SARNET project (Severe Accident Research Network of Excellence, 2004-2008 in 2009-2013) and CESAM project (Code for European Severe Accident Management, 2013-2017).

After the end of the CESAM project, the IRSN organized the ASCOM project, which will take place without funding from the European Commission, and invited the users of the ASTEC Program from previous projects to participate. The ASCOM project started on 1st October 2018 and will last until 30th September 2022. Although the project is not funded, the JSI's interest in participating is in access to the ASTEC program free of license fees, including user support. In the framework of the project, the JSI will mainly perform simulations of hydrogen combustion in the containment experimental facilities. The program will also be used to participate in the comparative calculation of the simulation of the accident in the generic model of the containment facility, which is carried out within the SAMHYCO-NET project (also in the IRSN organization). And, last but not least, with the ASTEC program, we will continue simulating the potential loss of coolant accidents and losses of cooling in the spent fuel pool of the nuclear power plant in Krško.

Since 2006 IRSN has been occasionally organizing meetings of ASTEC Users Club (approximately every two years), where ASTEC users present the results of simulations (carried out within or outside of European projects). At this meeting, dr. Ivo Kljenak presented the simulations of hydrogen combustion in the expanded experimental device THAI, which is located at Becker Technologies (Germany), in the presentation: "Simulation of THAI Hydrogen Combustion Experiments". The performed simulations represent the continuation of the JSI research within the CESAM project.

The initial meeting of the ASCOM project and the 8th meeting of the ASTEC Users Club, organized by the Institute of Radioprotection et de Sûreté Nucléaire (IRSN) from France from 7th to 11th October 2018 in Aix-en-Provence (France), was attended by the dr. Ivo Kljenak from the Department of Reactor Engineering IJS.

3rd SOTERIA project General Assembly meeting, Helsinki, Finland, 9.-10.10.2018

The SOTERIA project (»Safe long term operation of light water reactors based on improved understanding of radiation effects in nuclear structural materials«) is a four-year European project launched on 1.9.2015 under the auspices of Horizon 2020 EURATOM program. The main objective of the project is to improve understanding the phenomena of steel aging used for the production of reactor pressure vessels and its internal components. With the research in the field of steel aging, key information about this phenomenon will be provided to regulator and operator, which are necessary for the safe and long-term operation of existing European nuclear power plants. Many European research centers (including IJS) and industrial partners are involved in the project. The project coordinator is CEA, France.

At the 3rd meeting of the General Assembly, we verified the status of the project after 36 months of operation according to the set goals. We identified some minor delays in issuing internal reports, but there are no significant deviations from the set path. The JSI participates on the project in the development of the crystalline plastic model for the mechanical description of irradiated stainless steels and in the modeling of intercristal boundaries, in order to simulate early cracks. The JSI submitted a technical and financial report within the deadline; chapters for the internal and final content report were also contributed.

The meeting, organized by VTT in Helsinki, was attended by dr. Samir El Shawish from the Reactor Engineering Division.

8th working meeting of the SESAME project, TUD, Delft, the Netherlands

Project SESAME is a project within the European project Horizon 2020. The three main objectives of the SESAME project are: the development and validation of advanced numerical approaches for the design and safety evaluation of advanced reactors; achievement of a new or extended validation base by creation of new reference data; and establishment of Best Practice Guidelines. Project results are expected to be used in the planning and improvement of fourth generation reactors such as ASTRID, MYRRHA, ALFRED and SEALER. The project is divided into 7 work packages. 23 organizations from the European Union and two organizations from the USA are involved in the project.

In the first, common part of the meeting, organizations that prepare experimental facilities and the simulations of these, present progress in the facilities construction, experimental work and analysis of the simulation results. The meeting continued with joint and distributed work by individual work packages.

The meeting took place from 2nd to 4th of October at the premises of the TUD organization in Delft in the Netherlands. The meeting was attended by Jure Oder as a representative of the Reactor Engineering Division. In the first part of the meeting, he presented results of a direct numerical simulation of liquid sodium through a backward step with a heater.

NARSIS Project meeting, Karlsruhe, Germany, 18-20.9.2018

NARSIS (New Approach to Reactor Safety ImprovementS) is a four-year European project of the Horizon 2020 Framework Program, of which the main objectives are to fill identified weaknesses in the security analysis of external threats and to propose recommendations for future legislation. The first three work assemblies are of a research nature, and the fourth and fifth are applicative. The Jožef Stefan Institute, Reactor Engineering Division (IJS, R-4) participates in the  first four and in the sixth work assembly. The first working set is intended to characterize physical threats due to various external threats and scenarios. The second work unit is designed to assess the main critical components of the nuclear power plant. The third set of work is intended for common risk and safety analyses, and the fourth is intended for a comparison of different security approaches for safety assessment in the case of an actual reactor. The fifth working group is intended for tools to support the handling of serious accidents, and the sixth to disseminate the results achieved in the project.

The meeting was divided into two parts. Firstly, the General Assembly was held, where representatives of the participating organizations were informed by the on the current state of the project and the way the documents are exchanged. The coordinator reported on the forthcoming financial reporting to the European Commission and the planned meeting and workshop in 2019. In the second part, a plenary session was held where the heads of work units presented the work done in individual sections. A discussion on the tools that are planned for use as part of the NARSIS project was followed. On the last day, a debate was held on open issues and the exchange of data between individual work packages.

The NARSIS meeting, which was hosted from september 18. - 20. in Karlsruhe Institute of Technology (KIT) was attended by dr. Andrija Volkanovski and dr. Andrej Prošek.

ETSON association JSP section summer workshop

Within the framework of the European Technical Safety Organizations Network (ETSON) is also a section for younger employees of ETSON (JSP) members. The JSP section regularly organizes summer workshops with the purpose of exchanging experiences, identifying good practice and networking.

This year's summer workshop was organized by the Romanian RATEN ICN. The title of the workshop was "Radioactive waste management, environmental protection and decommissioning." The summer workshop consisted of three parts. In the first part, ETSON members introduced themselves. The presentation of the Jožef Stefan Institute (JSI) with an emphasis on the role of the JSI as an authorized agent, research in the field of nuclear technology and integration into the international space was prepared by dr. Mitja Uršič. The second part was devoted to presentations, discussions and workshops on radioactive waste management, storage and disposal of radioactive waste, practices in the decommissioning of facilities and the transport of radioactive materials. The third part was intended for technical visits to the double TRIGA reactor, hot cells and radioactive waste processing plant. The workshop also hosted a meeting of delegates and representatives of JSP. Dr. Mitja Uršič, JSP delegate for the JSI also participated at the meeting.

Workshop, held between September 3rd and 7th, 2018 in RATEN ICN, Mioveni, Romania, was attended by dr. Mitja Uršič from Reactor Engineering Division. The meetings were also attended by representatives of JSP from the following members of ETSON: Romanian RATEN ICN, French IRSN, Belgian BelV, Russian SEC NRS, Italian ENEA, Lithuanian LEI, German GRS, British Wood RSD, Czech CV Rez and Finnish VTT. The workshop was also attended by representatives of the Romanian Administrative Authority.

18th UIT Summer School on Advanced experimental techniques in heat and mass transfer  

"UIT Summer School" is a course organized by the Italian Association of Experts in Thermodynamics UIT (Unione Italiana Termofluidodinamica) and is intended primarily for Ph.D. students. It covers the field of multiphase flows, heat transfer and related measurements. The course is carried out in two years, this year with the main theme of the course being the experimental method used to measure these phenomena. Next year the emphasis will be on numerical treatment. Approximately 20 participants attended the course.

The course was organized for the 18^th time by the UIT and hosted by the university conference center la Certosa di Pontignano near Siena (Italy). It was held between September 2^nd  and 8^th 2018. It was attended by Boštjan Zajec.

Computational Fluid Dynamics for Nuclear Reactor Safety (CFD4NRS), Shanghai, PR China, 4.9.2018 – 6.9.2018

The last two decades have witnessed an increasing use of three dimensional (3D) CFD and CMFD simulation techniques in nuclear reactor technology, in recognition of the fact that a number of important thermal-hydraulic phenomena cannot be predicted to the required accuracy and spatial resolution using traditional one-dimensional system codes. Requirements for validation of models used in CFD codes with the results of appropriate experiments prompted a joint OECD/NEA and IAEA initiative to form groups of experts with the specific task of addressing the maturity of CFD codes for NPP applications. Computational Fluid Dynamics for Nuclear Reactor Safety (CFD4NRS) workshop are intended to:

1. Set down Best Practice Guidelines for the use of CFD simulation techniques.
2. To document the validation database on which the level of maturity of CFD codes may be judged.
3. To catalogue the extensions needed to current CFD codes to enable them to perform trustworthy multi-phase simulations.
4. Review the methods for uncertainty quantification of CFD.

This was already seventh CFD4NRS workshop and was hosted by the Shanghai Jiao Tong University in PR China from 4 to 6 September 2018. Experimentalists and nuclear safety researchers using CFD codes in various applications of nuclear power plants exchanged their views on improving the experiments and validating CFD programs. Various authors presented their work in the fields of single-phase and multi-phase heat transfer, free-surface flows, condensation and turbulent mixing. The topics discussed refer to security problems in nuclear power plants such as pressurized thermal shock, critical heat flux, pool heat exchangers, spent fuel pool issues, boron dilution, hydrogen distribution in containments, design optimization...

The seventh version of the workshop was attended by Rok Krpan, a member of the Reactor Engineering Division of Jožef Stefan Institute.

Participation in the course of the SOTERIA project, PUV - Polytechnic University of Valencia, Spain, 3.-7.9.2018

The SOTERIA project (»Safe long term operation of light water reactors based on improved understanding of radiation effects in nuclear structural materials«) is a four-year European project, launched on 1.9.2015 under the auspices of EURATOM in Horizon 2020. The main objective of the project is to improve understanding the phenomena of steel aging used for the production of reactor pressure vessels and its internal components. With the research in the field of steel aging, key information about this phenomenon will be provided to regulator and operator, which are necessary for the safe and long-term operation of existing European nuclear power plants. Many European research centers (including IJS) and industrial partners are involved in the project. The project coordinator is CEA, France.

As the project approaches the last year of operation, a course was organized within the framework of the WP6 »Dissemination, exploitation, training and end-user assessment« course in order to inform the public, especially students and professionals at the beginning of the career path, about the most important results of the project. At the same time, the purpose of the course was to link the groups of experimenters and theoreticians involved in modeling. The course had three sections that followed the structure of the project: reactor pressure vessels (»RPV«), internal structure of the reactor (»internals«) and multi-level modeling. In addition to the lectures, the course also offered interactive sections where we tested the operation of a computer platform, in which various tools, (simplified) models and databases are integrated with which the user becomes acquainted with the basic mechanisms and the effects of various parameters on steel aging.

The course, organized by TECNATOM, S.A. in Valencia, was attended by dr. Samir El Shawish of the Reactor Engineering Division, Jožef Stefan Institute.

Analysis to Support Implementation in Practice of Articles 8a-8c of Directive 2014/87/Euratom Workshop, 4th-5th July  2018, Luxembourg

The Energy Directorate of the European Commission ordered a study at ETSON on the implementation of the European Nuclear Safety Directive from 2014 into national legislation. The focus of the project is the implementation of the post-Fukushima safety requirements and measures. The project is coordinated by the German GRS; the IJS also participates as an ETSON members.

The purpose of the first workshop was to review the work done so far for the following work packages:

1. “Review and assessment of international and European guidance documents”, run by German GRS,
2. “Assessment of approaches and methodologies set in place at national Levels for the Implementation of the EU Safety Directive ", led by the French IRSN,
3. “Performing a detailed study of the safety upgrades and existing reactors performed in selected Member States" conducted by the Department of Reactor Engineering.

Within the third work package, prof. dr. Leon Cizelj presented the draft report: “L. Cizelj, A. Prošek, A. Volkanovski, M. Uršič, Implementation and Practice of Articles 8a-8c of Directive 2014/87 / EURATOM - Reactor Safety Upgrades in Slovenia”.

Prof. dr. Leon Cizelj, head of the Reactor Engineering Division, and dr. Mitja Uršič attended the Workshop, which took place on 4th and 5th July 2018 in Luxembourg. The representatives of the Energy Directorate of the European Commission, ETSON representatives (JSI, German GRS, French IRSN, Belgian Bel V, Lithuanian LEI, Slovak VUJE, Czech CV Rez, Hungarian MTA-EK, Romanian RATEN ICE and Finnish VTT ), a representative of the OECD / NEA, representatives of the administrative authorities (the Netherlands, Germany, Belgium, Sweden, Slovakia, Romania), representatives of the EC JRC and the representative of the industry (ENISS) also attended the workshop.

CSARP / MCAP Meeting and MELCOR Users Workshop, Rockville, Maryland, USA, 4. – 15. 6. 2018

After a severe accident in the Fukushima nuclear power plant, nuclear safety standards have been increased. Consequently, severe-accident analyses are becoming an integral part of safety reports. To verify the analysis of severe accidents independently the MELCOR computer program is used, which can be obtained through participation in the U.S. NRC international cooperative research program CSARP (Cooperative Severe Accident Research Program). Slovenia has been a member of the CSARP program since the end of 2015, and has participated in it also in the period 1998-2005. As part of the CSARP research program, the CSARP/MCAP (MELCOR Code Assessment Program) is taking place every year in the USA. Because the use of the program is spread all over the world, the yearly meetings are also takin place in Europe (EMUG - European MELCOR User Group) and Asia (AMUG - Asian MELCOR User Group).

This year's CSARP / MCAP meeting took place in Rockville, Maryland, USA from 5th to 8th June 2018. Participants from 21 countries attended the meeting.  At the meeting the U.S. NRC, which runs CSARP program, MELCOR developers from Sandia National Laboratories, Albuquerque, New Mexico, USA, and CSARP partners presented their activities. The meeting was divided into the following sections:

• Severe accidents research - activities, computer programs and experiments,
• Reactor analyses and analyses of the spent fuel pool,
• Corium cooling,
• Specific topics in the field of severe accidents,
• Application and evaluation of the MELCOR program.

After the meeting, from 11th to 15th June, the workshop for users of the MELCOR program took place. The workshop was held in the form of lectures by MELCOR developers and participants' exercise on their computers.

Meetings and workshop were attended by dr. Matjaž Leskovar from the Jožef Stefan Institute Reactor Engineering Division, who is the Slovenian coordinator for cooperation within the CSARP research program. At the CSARP meeting, he chaired the section "Severe Accident Research: Computer Programs and Experiments", and at the MCAP meeting, he held a presentation entitled "Overview of MELCOR Activities in Slovenia".

SAMHYCO-NET second meeting, Karlsruhe, Germany, 3rd – 7th June 2018

The SAMHYCO-NET project is an in-kind project, created on the initiative of the “Institute of Radioprotection et de Sûreté Nucléaire (IRSN)” from France. The purpose of the project is the cooperation of research organizations in the field of hydrogen and carbon monoxide risk during a severe accident in a nuclear power plant. The content of the project involves the use of passive autocatalytic recombiners to reduce the amount of hydrogen, combustion of hydrogen and carbon monoxide in the nuclear power plant containment and simulate a severe accident scenario in a generic model of a containment involving the generation and combustion of hydrogen and carbon monoxide.

At the meeting, the participants presented their intended contributions with which they intend to participate in the project. A number of participating institutions will make available existing experimental results, while some will undertake new experiments only for the purposes of this project. Consequently, one of the results of the cooperation on the project will be the access to a lot of new experimental results from the field of hydrogen and carbon monoxide combustion. IJS intends to participate in the SAMHYCO-NET project by co-operating in simulating a serious accident in the generic model of containment and by continuing the simulations of hydrogen combustion experiments in experimental containment facility, which are carried out in cooperation with the Nuclear Research and Consultancy Group (NRG) from Netherlands for several years. At the meeting Tadej Holler, from IJS R4 division, presented the current and planned activities of the JSI in the field of computer simulations of hydrogen combustion.

The next meeting of the project is scheduled for April 2019 at IRSN headquarters in Fontenay-aux-Roses, France.

12th International Conference of the Croatian Nuclear Society - Nuclear Option for CO2 Free Energy Generation

The two-year international conference "Nuclear Option for CO2 Free Energy Generation" is organized by the Croatian Nuclear Society (HND). The conference covers the following areas related to the use of nuclear power: nuclear reactor technology, reactor physics, fuel cycle, nuclear safety, radioactive waste management and disposal, operational experiences, environmental impact, public relations and legislation.

At this year's conference, seven invited lecturers discussed the following topics: the design of new small modular reactors, the improvement of safety in existing power plants, the elimination of nuclear power plant faults, operational experiences, compliance with the Paris Agreement, the thorium cycle and the disposal of radioactive waste. A roundtable discussion on challenges and opportunities in knowledge management took place. Discussions were also held on the progress in the development of small modular reactors, with an emphasis on opportunities for Europe. At the conference, 86 contributions were presented, among them two from the Reactor Engineering Division:

• Prošek, M. Uršič, Review of design extension experiments and analyzes for non-degraded core, and
• Uršič, M. Leskovar, V. Centrih, Study on premixture formation during fuel-sodium interaction.

The 12th international conference, held between June 3 and 6, 2018 in Zadar, Croatia, was attended by dr. Mitja Uršič from the Reactor Engineering Division. About 130 experts from around the world attended the meetings.

Spring 2018 CAMP meeting, Ottawa, Canada, 28.5. - 30.5.2018

CAMP (Code Applications and Maintenance Program) is the largest research program under the auspices of the United States Nuclear Regulatory Commission (U.S. NRC) since 1993. Within the framework of the CAMP research program, the development and exchange of experience on system software RELAP5 and TRACE, neutronics program PARCS and graphical interface SNAP take place. In the CAMP, based on an agreement with the U.S. NRC, administrative bodies, research organizations and industry representatives from more than 20 countries are involved. Coordinator for Slovenia is the "Jožef Stefan" Institute (JSI) (in addition to JSI, Krško Nuclear Power Plant and the Slovenian Nuclear Safety Administration are participating).

The CAMP Spring Meeting was divided into two parts, namely technical and program part. In the technical part, the development of the RELAP5 and TRACE programs was first presented. Then, several CAMP countries (Belgium, Canada, Spain, South Korea, Slovenia) presented their reports. The JSI presented the contribution:

• "Status of CAMP activities in Slovenia" (Andrej Prošek, Janez Kokalj).

The status reports on the NRC programs TRACE, PARCS, RELAP5 and SNAP followed. Finally, technical reports were presented.

Within the program part of the CAMP meeting, we discussed the need for further development of computer programs and tools for simulation of nuclear installations, as well as proposals for contributions in kind, which are a requirement for all participants in the CAMP.

This year's CAMP Spring Meeting, which was held from 28 - 30 May 2018 in Ottawa, Canada, was organized by the Canadian Nuclear Safety Agency (CNSC). Approximately 30 representatives attended the meetings. Janez Kokalj attended the meeting from the JSI, Reactor Engineering Division.

BEPU 2018 Conference, Lucca, Italy, 13.05. - 19.05, 2018

The BEPU-2018 International Conference (Best Uncertainty Plus Assessment) covers developments, applications and advancements in simulation programs and methods for calculating uncertainties in nuclear safety and technology. The last such type of conference was organized by the American Nuclear Society of America (American Nuclear Society) in Washington in 2000 and 2004. The first two conferences were limited to the field of thermo-hydraulics. This year's conference included a much broader spectrum of calculation uncertainty, among which methods of uncertainty in CFD (Computational Fluid Dynamics), structural analysis, reactor physics, and the uncertainty of other more complex simulations in the field of nuclear technology. The BEPU-2018 conference was held in the Italian city of Lucca by the local organization NINE (Nuclear and Industrial Engineering), and sponsored by ANS, the IAEA (International Atomic Energy Agency) at the NEA (Nuclear Energy Agency).

The conference program covered 6 different technical areas. There were 5 plenary sessions with 13 invited lectures and about 30 parallel technical sessions with more than 100 oral presentations. In six days of the conference, 6 different panel discussions were also held. Informal meetings at the conference were also important.

The conference in Lucca was attended by dr. Boštjan Končar from the Reactor Engineering Division, JSI. At the conference he presented the contribution entitled »BEPU application to CFD benchmark« by the authors of A. Prošek, ​​B. Končar and M. Leskovar.

WP5 Workgroup SOTERIA Project meeting, EDF Lab Les Renardières, France, 17-18 May 2018

The SOTERIA project (»Safe long term operation of light water reactors based on improved understanding of radiation effects in nuclear structural materials«) is a four-year long European project launched on 1.9.2015 under the auspices of EURATOM in Horizon 2020. The main objective of the project is to improve the understanding of aging of steels used for the production of reactor pressure vessels and its internal components. With the research in the field of steel aging, key information which are necessary for the safe and long-term operation of existing European nuclear power plants, will be provided to the regulators and operators. Many European research centers (including IJS) and industrial partners are involved in the project. The project coordinator is CEA, France.

At the meeting of the WP5 workgroup, which deals with modeling and simulations, the work results of the first 30 months of the project were presented. The IJS participates in the project in

• developing a model of crystalline plasticity for a mechanical description of neutron irradiated steels and
• modeling of intercrystalline borders to simulate early damage or cracks.

At the meeting, the IJS together with IRSN, CNRS and CEA presented a comparison of two methods - the finite element method and the fast Fourier transform method - in the case of a tensile load of an irradiated polycrystalline aggregate. The title of the presentation was: »Intergranular stress calculation and irradiated stainless steel model using FEM and FFT approaches«.

The meeting, organized by the EDF in Les Renardierès, was attended by dr. Samir El Shawish of the Reactor Engineering Division from Jožef Stefan Institute.

GA-21 EUROfusion, Sofia, Bolgaria, 10.04.-12.04., 2018

European fusion research under Horizon 2020 brings together the targeted 5-year (2014-2018) fusion program EUROfusion, under the auspices of the EURATOM Treaty. The main objectives of the EU's fusion research are related to support of the ITER fusion reactor and, in the long term, the realization of the demonstration fusion power plant. The EUROfusion program is implemented by a consortium of EU member states' fusion research units (29 in total), where the Jožef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The leading partner in the consortium is the Institute of Plasma Physics (IPP), Germany. The decision-making body of the consortium is the General Assembly.

On April 11 and 12, 2018, 21st meeting of the General Assembly of EUROfusion took place in Sofia, Bolaria. The meeting was organized by Institute INRNE, Sofia. At the meeting, we became acquainted with the status of the Italian proposal of the I-DTT device, designed to test alternative diverter configurations. The location for I-DTT is already selected, the experimental facility will be built in the area of ​​the Frascati Research Center, in the province of Lazio. The Italian representative presented the proposed parameters and research objectives of the device. If the planning and construction of I-DTT will progress according to the foreseen plan, this device could become part of the European fusion program in the next research framework programme FP9, and a certain amount of financial resources will be reserved for this purpose. The EUROfusion program will be extended until the end of Horizon 2020. The formal decision of the European Commission is expected to be adopted during the Bulgarian Presidency of the European Union. For the years 2019 and 2020, the EC already envisaged 159 Mio EUR and 169 Mio EUR, of which 60 Mio EUR for DT and TT experimental campaigns on the European JET Tokamak. We also confirmed the new head of the EUROfusion administrative unit, Emilio Genengeli, ENEA. Regarding Brexit, the British representative informed the Assembly that the British government had adopted a government document in January this year, which for the first time clearly shows the willingness to continue the activities under the Euratom Treaty. The general assembly of EUROfusion was attended by Dr. Boštjan Končar from the Reactor Engineering Division, JSI.

22nd meeting of SNETP Management Board, Brussels, 24.1.2018

The European Technology Platform for Sustainable Nuclear Energy SNETP, joins more than 117 nuclear stakeholders from all European nuclear countries. Among the key objectives of the platform is the preparation of strategic development documents, especially for research and development in the field of 2nd and 3rd generation reactors, 4th generation and cogeneration of heat and electricity with nuclear reactors. In the framework research programs, the European Commission co-finances projects that relate to strategic development priorities prepared and mutually coordinated by stakeholders of the platform.

The Governing Board took note of preparations for the registration of SNETP in the legal form of the international non-profit association AISBL under Belgian law. The establishment and the start of operations are expected in the second half of 2018.

The meeting, hosted by the Belgian Nuclear Research Institute - SCK-CEN, was attended by prof. dr. Leon Cizelj, head of Reactor Engineering Division.

General Assembly, Governing Board and 15th Anniversary of ENEN, Brussels, Belgium, 28.2.-2.3.2018

More than 60 ENEN members represent the majority of European universities and research institutes that educate in the field of safe use of nuclear energy. In the 15 years of its existence, the association succeeded to develop standard curricula, mutual recognition of credits, a relatively large exchange of students and teachers, and several pilot training schemes.

On the 15th anniversary, a number of high-ranking guests attended the colloquium, which discussed the challenges and opportunities for education and training in nuclear science and technology. We agreed that all stakeholders in the future should focus more intensively on attracting, developing and retaining new talent in nuclear careers.

The Governing Board and the Assembly discussed about the current state of transfer of activities from ENEN registered in France to ENEN AISBL, which we registered as an international non-profit association in Belgium. Currently, all business is carried out through ENEN, and the transfer to ENEN AISBL is planned in June 2018.

ENEN association awards the title of European magister of nuclear technology to nuclear engineering graduates, who have completed their study at ENEN member university in the amount of 300 ECTS (5 years), while at least 20 ECTS have been obtained through studies or research work in other ENEN members. Over the course of ten years, more than 150 young graduates have received this title.

General assembly, governing board meeting and celebration of the 15th anniversary of the association, held on the 1st and 2^nd March were organized in Brussels by ENEN and it was attended by prof.dr. Leon Cizelj, head of the Reactor Engineering Division and President of ENEN.

Initial meeting of the ENER / D3 / 2017-209-2 project, Luxembourg, Luxembourg, 18-19 February 2018

The Directorate-General for Energy of the European Commission commissioned the association of authorized nuclear safety experts - ETSON to study the implementation of the european nuclear safety directive from 2014 in the national legislation. The focus of the project is on the implementation of the post-Fukushima security requirements and measures.

The project is co-ordinated by the German GRS, and in addition to the other ETSON members, the JSI-R4 also participates as a leader of the work package " Performing a detailed study on the safety upgrades in existing reactors performed in selected Member States ". Slovenia is currently the leader in this field in Europe.

The meeting, organized by the Directorate-General for Energy in Luxembourg, was attended by prof. dr. Leon Cizelj, Head of the Reactor Engineering Division, JSI.

Seminar "Euratom Nuclear Fission Research and Training: What Are the New Needs?" and the General Assembly of the SNETP, Brussels, Belgium, 20. - 22. 2. 2018

The European Commission organized a seminar on needs in nuclear research and education, in which it sought to obtain, the opinions and ideas of stakeholders on the substantive priorities for the 9th framework program. Prof. dr. Leon Cizelj, head of the Reactor engineering division and president of the ENEN Committee, was invited as a moderator of the discussions on education and training.

The SNETP Assembly get acquainted with the preparations for registering SNETP in the legal form of the international non-profit association AISBL under Belgian legislation and confirmed the following steps in this process. The establishment and the start of operations are expected in the second half of 2018.

The events, organized by the European Commission and SNETP in Brussels, were attended by prof. dr. Leon Cizelj, head of the Reactor engineering division, JSI.

Final Meeting of WPDC (Diagnostic & Control), Garching, Germany, 20.12.2017

The WPDC (Diagnostic & Control) project is one of the European Fusion Development Association's strategic missions to achieve the long-term goal of building the DEMO demonstration fusion power plant by the year 2050. The WPDC project aims to provide an integrated concept for the design of diagnostic and control systems in the DEMO power plant.

At the closing meeting for 2017, the representatives of the partner organizations in the project presented the results of their work in 2017 by individual fields. The JSI participates on the project in the WP2 work package "System engineering and design integration", whereby system engineering is performed by the subcontractor Cosylab d.d. and the design integration and the associated engineering calculations are performed by the Reactor Engineering Division. At the meeting, Cosylab d.d. and the JSI separately presented their results and contributions. The JSI presented the analysis of the influence of the thermal-electric current on the mechanical stresses in the divertor. At the meeting, we also agreed to define in detail the specification of works for the year 2018 in the coming weeks.

Meeting held on 20.12. at Garching, was organized by the project manager Wolfgang Biel, and was attended by dr. Samir El Shawish from Jožef Stefan Institute Reactor Engineering Division.

GA-20 EUROfusion, Barcelona, ​​Spain, 18-19 December, 2017

European fusion research under Horizon 2020 brings together the targeted 5-year (2014-2018) fusion program named EUROfusion, under the auspices of the EURATOM contract. The EU's main objectives of fusion research are related to support of the ITER fusion reactor and, in the long term, the implementation of the demonstration fusion power plant. The EUROfusion program is implemented by a consortium of Member States' fusion research units (29 in total), where the Jožef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The leading partner in the consortium is the Institute of Plasma Physics (IPP), Germany. The decision-making body of the consortium is the general assembly.

On 18.12. and on 19.12.2017, the 20th meeting of the General Assembly of EUROfusion took place in Barcelona, ​​Spain. The meeting was organized at the headquarters of the ITER European Agency (F4E). At the meeting, we discussed the report of the Expert Group on the European program of breeding blankets. The main purpose of the expert group was to harmonize the Test Blanket Module Test (TBM) program in ITER, coordinated by F4E and the project of development of breeding blankets for DEMO reactor - Work Package Breeding Blanket (WPBB), which is in the EUROfusion program. The Group has made several technical and program recommendations in the direction of program consistency. The main changes to the TBM program for ITER include the incorporation of a water-cooled coating into the test program and the financial and personnel participation of EUROfusion in the TBM program. The Assembly approved the proposed amendments. Part of the EUROfusion program also includes smaller fusion devices in Europe. At the meeting were presented the progress of the COMPASS tokamak upgrade in the Czech Republic and the status of the EDIPO Testing Device in Switzerland, aimed at testing high magnetic fields, above 10 T. Dr. Boštjan Končar from the Reactor Engineering Division, IJS, attended the General Meeting of the EUROfusion.

Working meeting within the H2020 project ANNETTE, Halden, Norway, 10.12.-12.12.2017

The ANNETTE project (Networks for Nuclear Education and Transfer of Expertise) is aimed at promoting coordinated participation of all nuclear stakeholders in the planning and delivery of education and training. The project, which has 24 partners, is co-financed by the European Commission under Horizon 2020 (EURATOM Fission).

The meeting was dedicated to the planning and final division of work between partners in the Work Package 5, which is dedicated to education in the field of nuclear safety culture. The role of the associates of the Jožef Stefan Institute in the project is to coordinate cooperation with technological platforms and other professional associations in Europe, as well as beyond its borders.

The meeting, organized by the Uppsala University at the premises of the Norwegian Energy Institute IFE, was attended by prof. dr. Leon Cizelj, Head of the Reactor Engineering Division.

EUROSAFE Forum, TSO Cafe, Governing Board and General Assembly of ETSON, Paris, France, 5.11.-8.11.2017

The EUROSAFE Forum was held on 6th and 7th of November in 2017. It was organized by IRSN in Paris and is intended primarily for authorized experts in nuclear and radiation safety. Leading partners are Bel V ​​(Belgium), GRS (Germany) and IRSN (France), while the IJS is one of the partners. About 300 participants took part in the conference. In the first plenary session of the conference, the emphasis was on the harmonization of nuclear regulations in Europe, the challenges of nuclear safety in France and the response to the health crisis in the onset of the Ebola virus in Guinea. During the conference, the presentation of authorized experts, members of ETSON, where the IJS was presented, by Ms. Tanja Klopčič. In the second part of the conference, the main topics were nuclear safety and security, radioactive materials management and radiation safety.

On the 8.of November the ETSON organized several meetings at the IRSN (Fontenay aux Roses). Prof. dr. Leon Cizelj attended the meeting of the Management Board and the General Assembly. The ETSON Association was established with the aim of expert networking of accredited experts for nuclear and radiation safety. The association brings together experts from the Member States of the European Community, Japan, Russia and Ukraine.

ANS Winter Meeting, Washington, USA, 28.10.-2.11.2017

Each year, the American Nuclear Society organizes two major conferences called the Summer and Winter Meetings. The winter meeting in 2017 was dedicated primarily to the status and perspectives of the nuclear energy in the US and around the world, and in this connection also with prospects and opportunities for young people who are choosing a career path.

It is customary to conduct a number of accompanying meetings during the conference. For us interesting meetings were held by Nuclear Engineering Department Heads Organization and the Committee on International Cooperation.

Conference and accompanying meetings were attended by prof. dr. Leon Cizelj, head of the Reactor Engineering Division.

ENEN+ meeting for work packages WP1 and WP2 Budapest,

Hungary, 30. 11. - 1. 12. 2017

The ENEN+ project entitled "Attract, Retain and Develop New Nuclear Talents Beyond Academic Curricula" belongs to the portfolio of Horizon 2020 EURATOM projects. The main purpose of the ENEN+ project is to contribute to the revitalization of the interests of younger generations for occupations in the nuclear sector. For this purpose, the following main activities are foreseen:

• Attract new talents to careers in nuclear.
• Develop the attracted talents beyond academic curricula.
• Increase the retention of attracted talents in nuclear careers.
• Involve the nuclear stakeholders within EU and beyond.
• A revitalized interest in nuclear professions through the establishment of a mobility fund and the voluntary accreditation of nuclear education and training.

The 22 partners of the ENEN + project will focus mainly on professions and experts in the fields of nuclear technology and safety, the disposal of radioactive waste, radiation protection and nuclear applications in medicine. Among the partners are European universities and research institutes, industry (Westinghouse, Tecnatom, EDF) and international organizations (ENS, FORATOM, IAEA, NUGENIA, EFOMP), and from Slovenia “Jožef Stefan” Institute and the Faculty of Mathematics and Physics of the University of Ljubljana. The project is coordinated by ENEN, led by prof. dr. Leon Cizelj from the Reactor Engineering Division from the “Jožef Stefan” Institute.

The ENEN + project meeting for the WP1 "Attract new nuclear talents in secondary schools" and WP2 "Increase attraction and retention of new talents among undergraduate students" took place at Budapest University of Technology and Economics, Institute of Nuclear Techniques from 30.11.-1.12. 2017. At the meeting, the participants in the project agreed on the implementation of the planned activities and on concrete assignments. The meeting was attended by dr. Matjaz Leskovar from the Reactor Engineering Division from the “Jožef Stefan” Institute.

Fall 2017 CAMP Meeting,

University of Michigan, MI, Ann Arbor, USA, 28 - 30. 11. 2017

CAMP (Code Applications and Maintenance Program) is a research program under the auspices of the US NRC (Nuclear Regulatory Commission) since 1993. Within the framework of the CAMP research program, the development and exchange of experience regarding the RELAP5 and TRACE system software programs, the PARCS neutron program and the SNAP graphic interface are under way. In the CAMP, based on an agreement with the U.S. NRC currently participates in more than 20 countries. “Jožef Stefan” Institute (JSI) is the coordinator for Slovenia (besides the IJS, the Nuclear Power Plant Krško and the Slovenian Nuclear Safety Administration also participate).

The CAMP Autumn Meeting was divided into two parts: technical and programmatic. In the technical part, the U.S. NRC presented the development status of U.S. NRC computer programs TRACE, RELAP5, PARCS and SNAP. Reports of nine CAMP member countries (Finland, Croatia, South Korea, Canada, Poland, Slovenia, Sweden, Switzerland and Taiwan) followed. The IJS presented the contribution:

• "Status of CAMP Activities in Slovenia" by Andrej Prošek.

18 technical reports were presented, related to the use of computer programs RELAP5, TRACE and PARCS. Within the program part of the CAMP meeting, we discussed the need for further development of system programs for the simulation of nuclear facilities and proposals for contributions in kind. JSI proposed a contribution in kind for the year 2018 entitled "Semiscale S-NC-02 and S-NC-03 natural circulation tests performed by RELAP5 / MOD3.3 Patch 5", which was approved by the technical program committee.

This year's CAMP autumn meeting, held from 28-30 November 2017 at the University of Michigan, Ann Arbor, USA, was organized by the University of Michigan, the Department of Nuclear Engineering and Radiological Science under the auspices of the U.S. NRC. Nearly 50 representatives from 16 countries attended the meetings, of which one third from the host country. From the JSI, Reactor Engineering Division, the meeting was attended by dr. Andrej Prošek.

Third meeting on MITHYGENE-ETSON hydrogen deflagration benchmark

Paris, France, 22nd and 23rd November 2017

As part of the French MITHYGENE project, active since 2013, joined by members of ETSON, the ENACCEF2 experimental device was designed and built, offering unique possibilities for studying accelerating and quenching of the flame. Some of the hydrogen combustion experiments carried out in the project will also be used as a measure (combustion benchmark) for a comparative study of the calculation codes used in safety analyzes of hydrogen combustion in nuclear power plants containments. ETSON is a European association of certified experts for nuclear (and radiation) Safety. Several working groups and committees work within the association.

At the third meeting, the partners presented and analyzed the results of simulations of the second part, where the results of the experiments were not known in advance. The results for IJS were contributed from Ivo Kljenak and Tadej Holler. The results of first were obtained using ASTEC system code, while the second acquired the results using the ANSYS Fluent CFD code.

IRSN will as the project coordinator in cooperation with its partners, issue a benchmark report on the hydrogen combustion study in the ENACCEF2 experimental facility in January 2017. Prior to this, the partners will contribute possibly improved second phase results, taking into account the known results of the experiments.

The third meeting for the MITHYGENE-ETSON combustion benchmark, which was again hosted by IRSN at its premises in Fontenay-aux-Roses on the outskirts of Paris, took place on 22 and 23 November 2017. As a representative of the Jožef Stefan Institute, Tadej Holler from the Reactor Engineering Division.

2nd meeting of the General Assembly of the SOTERIA project, Madrid, Spain, 6-8 November 2017

The SOTERIA project ("Safe long-term operation of light-water reactors based on a better understanding of radiation effects in nuclear structural materials") is a four-year European project launched on 1.9.2015 under the auspices of Horizon 2020 EURATOM project. The main objective of the project is to improve understanding the phenomena of steel aging used for the production of pressure pipelines and its internal components. With the research in the field of steel aging, key information will be provided to regulators and operators, which are necessary for the safe and long-term operation of existing European nuclear power plants. Many European research centres (including IJS) and industrial partners are involved in the project. The project coordinator is CEA (France).

At the 2nd meeting of the General Assembly, we verified the status of the project after 24 months of operation according to the goals set. We identified some minor delays in issuing internal reports, but no significant deviations from the scheduled plans were detected. The SOTERIA project received a positive assessment from the European Commission for the first 18 months of work. The JSI participates on the project in the development of a crystalline plastic model for the mechanical description of neutron-irradiated stainless steels and for the modelling of inside crystal borders to simulate the formation of early damage and cracks. At the meeting, the IJS presented two studies: the analysis of the accuracy of cohesive finite elements in the Abaqus program (titled Grain boundary modelling with cohesive zone approach) and the analysis of stress fields in large, realistic polycrystalline aggregates (titled: "Stress fields in large polycrystalline aggregates «) carried out by the JRC.

The meeting, organized by CIEMAT in Madrid, was attended by dr. Samir El Shawish from Reactor Engineering Division.

SAMHYCO-NET Kick-Off Meeting, Fontenay-aux-Roses, France

The SAMHYCO-NET project is an in-kind project, created on the initiative of the Institute of Radioprotection et de Sûreté Nucléaire (IRSN) from France. The purpose of the project is to involve research organizations in the field of hydrogen risk during a severe accident in a nuclear power plant. The project initiative followed the unsuccessful proposal of the SAMHYCO project for the European Commission's Horizon 2020 call. The project's content is part of the content foreseen in the SAMHYCO project: the use of passive autocatalytic hydrogen recombiners for lowering of the hydrogen concentration, the combustion of hydrogen in the nuclear power plant and the simulation of hydrogen combustion in the generic model of the containment chamber.

The initial meeting of the project was attended by representatives of the following organizations: NRG (Netherlands), Forschungszentrum Juelich (Germany), Becker Technologies (Germany), JAEA (Japan), Nagaoka University of Technology (Japan), MRI (Japan), CIEMAT (Spain), SSTC NRS (Ukraine), LEI (Lithuania), University College of Southeast Norway (Norway), KIT (Germany), Shanghai Jiao Tong University (China), JSI (Slovenia), CNRS (France) and EDF (France). At the meeting, all participants confirmed the intention to participate in the project, and presented what our (expected) contributions would be. Warsaw Institute of Technology (Poland) and PSI (Switzerland) will also participate in the project.

JSI intends to participate in the SAMHYCO-NET project by continuing simulations of hydrogen combustion experiments in experimental containment devices, which have been successfully carried out in cooperation with the Nuclear Research and Consultancy Group (NRG) from the Netherlands for many years. At the meeting, dr. Dirk Visser from NRG presented a joint presentation:

Hydrogen Deflagration Modelling (E. M. Komen, T. Holler, I. Kljenak, D. Visser).

The next project meeting is scheduled for June 2018 at the Karlsruhe Institute of Technology (Germany).

The SAMHYCO-NET Kick-Off Meeting, held on 18 and 19 October 2017 in Fontenay-aux-Roses (France), organized by the Institut de Radioprotection et de Sûreté Nucléaire (France), was attended by dr. Ivo Kljenak from the Reactor Engineering Division, JSI.

ENEN+ Kick-Off Meeting and ENEN Association Board of Governors Meeting, Brussels, Belgium, 2.-4. 10. 2017

ENEN+ Project entitled »Attract, Retain and Develop New Nuclear Talents Beyond Academic Curricula« belongs to the portfolio of EURATOM Horizon 2020 projects. The main purpose of ENEN + is to contribute to the revitalization of the interests of younger generations for occupations in the nuclear sector. For this purpose, the following activities are planned:

• Attract new talents for the nuclear professions.
• Develop new talents beyond academic curricula.
• Retain more new talents in nuclear professions through enhanced mentoring and mobility support.
• Include nuclear stakeholders in the European Community and abroad.
• A revitalized interest in nuclear professions through the establishment of a mobility fund and the voluntary accreditation of nuclear education and training.

The 22 partners of the ENEN + project will focus mainly on professions and experts in the fields of nuclear technology and safety, the disposal of radioactive waste, radiation protection and nuclear applications in medicine. Among the partners are European universities and research institutes, industry (Westinghouse, Tecnatom, EDF) and international organizations (ENS, FORATOM, IAEA, NUGENIA, EFOMP), and from Slovenia the Jožef Stefan Institute and the Faculty of Mathematics and Physics of the University of Ljubljana. The project is coordinated by ENEN, led by prof. dr. Leon Cizelj.

The kick-off meeting of the ENEN+ project took place at the premises of the European Commission in Brussels from October 2nd to October 3^rd 2017. At the meeting, the leaders of individual work packages and tasks presented the planned activities and discussed them with their partners. The kick-off meeting was attended by dr. Matjaž Leskovar and prof. dr. Leon Cizelj from the Reactor Engineering Division of Jožef Stefan Institute.

The next day was the meeting of the board of directors of ENEN, president of which is prof. dr. Leon Cizelj.

CSARP / MCAP meeting and MELCOR users workshop

After a severe accident in the Fukushima nuclear power plant, nuclear safety standards have been tightened. Thus, severe accident analyzes are becoming an integral part of the safety reports. To independently verify the analysis of severe accidents, the MELCOR computer program is mostly used. It can be obtained through participation in the U.S. NRC international cooperative research program CSARP (Cooperative Severe Accident Research Program). Slovenia has been a member of the CSARP program since the end of 2015, and has participated in it already before, in years between 1998 and 2005. As a part of the CSARP research program, the CSARP/MCAP meeting (MELCOR Code Assessment Program) is being held every year in the USA. Because of the wide use of the program, for many years also regional summer meetings for European (EMUG - European MELCOR User Group) and Asian (AMUG - Asian MELCOR User Group) MELCOR users have been held.

This year's CSARP/MCAP meeting was held in Bethesda, Maryland, USA between 12. and 15. September, 2017. Before the meeting, on September 11, was a workshop for the MELCOR users. About 50 participants from 22 countries participated at the workshop and at the meeting. The workshop was in the form of lectures by MELCOR developers and exercises for the participants on their computers. The workshop focused on a new models and capabilities of the MELCOR program. At the CSARP / MCAP meeting, the U.S. NRC, which runs the CSARP, MELCOR developers from Sandia National Laboratories, Albuquerque, New Mexico, USA, and CSARP partners presented their activities. The meeting was divided into the following sections:

• Severe accidents research - activities, computer programs and experiments,
• Reactor and spent fuel pool analysis,
• Fukushima and severe accident management,
• Fission product scrubbing research,
• MELCOR applications and assessment.

The meeting was attended by Dr. Matjaž Leskovar from the Reactor Engineering Division, Jožef Stefan Institute, who is the Slovenian coordinator for cooperation within the CSARP research program.

NURETH-17 Conference, 3. - 8. September 2017, Xi'an, Kitajska

From 3rd to 8th September 2017 two of our colleagues attended the 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics NURETH-17, organized by the Xi'an Jiaotong University and represents the most important global conference in the field of nuclear thermohydraulics.

At the conference, we presented or co-authored three articles:

• Quantification of the Discontinuity of the Temperature Variance Dissipation Rate at a Fluid-Solid Interface: A Wall-Resolved Large Eddy Simulation of Turbulent Channel Flow with Conjugate Heat Transfer. , Cedric Flageul, Iztok Tiselj, Sofiane Benhamadouche, Martin Ferrand (EDF R & D).
• Direct Numerical Simulations of Sodium Flow Over a Backward Facing Step, Jure Oder, Iztok Tiselj
• Design and Pre-Evaluation of a Backward Facing Step Experiment with Liquid Metal Coolant, Wadim Jaeger, Thomas Schaub Hahn, Wolfgang Hering, Ivan Otic (KIT), Afaque Shams (NRG), Jure Oder, Iztok Tiselj

The first one was created in the framework of our cooperation with Electricite de France (EDF) and the other two in the framework of the EU project H2020 SESAME. In addition, Iztok Tiselj led one of the sessions on the topic of computational fluid dynamics. The conference was also an opportunity for informal meetings with partners from our international research groups and for inclusion in new international project initiatives.

International Conference on Structural Mechanics in Reactor Technology (SMiRT), 20. - 25. Avgust 2017, Busan, South Korea

The international conference on Structural Mechanics in Reactor Technology (SMiRT) is a biennial conference organized since 1971 by the International Association for SMiRT (IASMiRT). The IASMiRT is a non-profit organization based in Berlin founded by Professor Thomas A. Jaeger. The participants of the conference become automatically part of the association and have the right to attend and vote in the general assembly organized during the conference.

About 610 abstracts were initially submitted to the 24th SMiRT conference. A total of 478 papers were orally presented during 10 technical sessions, 2 state of the art sessions and 10 special sessions organized in 7 parallel tracks. In total, 506 registered participants joined the conference mostly from Korea, Japan, China, UK, Germany and France. It was agreed during the general assembly that IASMiRT will change its registration country from Germany to USA, becoming thus an American organization. The reason for this being that full tax exempt of SMiRT conferences is no longer possible under German law.

The SMiRT 24 conference was hosted by the Korean Nuclear Society and the Korean Pressure Vessel and Piping association in Busan, South Korea from 20th to 25th of August, 2017. The conference was attended by Dr. Oriol Costa, research assistant of the Reactor Engineering Division of Jožef Stefan Institute. He presented a joined paper with the Finish research institute, VTT in the technical session of Characterization of Loads.

Presentation of the Reactor Engineering Division, JSI to the URSJV

On Wednesday, August 23, 2017, employees of the Reactor Engineering Division, JSI visit the URSJV (Uprava Republike Slovenije za jedrsko varnost – Slovenian Nuclear Safety Administration) to present their work and strengthen their contacts with the URSJV.

At the beginning, prof. Leon Cizelj, head of the Reactor Engineering Division, described the division's mission, key areas of activity and ongoing projects. He emphasized the role of authorized nuclear safety organizations in terms of their funding, independence, professionalism, research activity, the impartiality of their choice by the holder of the authorization and other parameters that are important for the quality work of the authorized organizations. The division members are active in education both within ENEN (European Nuclear Education Network) and at the Department of Reactor Engineering at the Faculty of Mathematics and Physics. He emphasized the international involvement of the department and the cooperation with various organizations, and sought to find comparability and differences with other authorized organizations in the world. He set his presentation as a challenge for further debate.

Presented was the research of the employees of the division in the following areas:

 - nuclear thermodynamics,

 - fatigue materials related to the aging of equipment,

 - probabilistic safety analyses, their input data and their use,

 - simulations of severe accidents with core melting and related experiments,

 - heat transfer and mechanical loads in individual components of the fusion power plant.

For many of the aforementioned research areas, the Reactor Engineering Division is the only organization in Slovenia that is working on it.

In conclusion, we all agreed that knowledge, including research by the division, is an important factor in ensuring nuclear safety so far and should remain so in the future. With regard to strategic guidelines, what to explore and where to get financing for this, further cooperation of all stakeholders will be needed.

Source: URSJV website http://www.ursjv.gov.si/en/info/novica/article/4597/5976/

Second MITHYGENE-ETSON hydrogen deflagration benchmark meeting,

Paris, France, June 16, 2017

As part of the French project MITHYGENE, active since 2013, and joined also by the ETSON members, an experimental device ENACCEF2 was designed and built. It offers unique possibilities for study of acceleration, deceleration and flame quenching. Some of the hydrogen combustion experiments within the project will be used also as a combustion benchmark for comparative study of calculation codes used in safety analysis of hydrogen combustion in nuclear power plants containments. ETSON is a European Technical Safety Organization Network. There are several working groups and committees in the framework of the association.

At the second meeting, the participating partners presented and analyzed the results of the open phase work simulations. From JSI, the results were contributed by Ivo Kljenak and Tadej Holler. The first one obtained his results using so-called system code ASTEC, while the other one used a computational fluid dynamics program ANSYS Fluent.

The last meeting will be held again at the IRSN in Paris and is foreseen for November 22 and 23, 2017. On this meeting, the results of the second phase will present, where the experimental results will not be known in advance.

The second MITHYGENE-ETSON combustion benchmark meeting was hosted by IRSN in in Paris on June 16, 2017. As a representative from Jožef Stefan Institute, it was attended by Tadej Holler from the Reactor Engineering Division.

Lecture at the regional course for the DEVCO Directorate

Yerevan, Armenia, 26-28 April 2017

Within the framework of the Instrument for Nuclear Safety Cooperation (INSC) funded by the European Commission within the DEVCO Directorate, we are involved in the training of members of nuclear regulatory authorities and their authorized experts in third countries.

Most courses were conducted at home in cooperation with the ICJT. This time exceptionally, we also helped implementing the regional course in Yerevan, Armenia.

At a course organized by the coordinator of the ITER Consult project in Yerevan, Armenia, lectured also prof. Dr. Leon Cizelj, Head of the Reactor Engineering Division, JSI .

Meeting for the preparation of the SET action plan for the nuclear energy

Brussels, Belgium, 13.7.2017

Strategic Energy Technologies (SET) Plan is one of the European Union's most important strategic documents in the field of energy development and research. It is prepared by the European Commission and it is confirmed by the Steering Committee, composed of the Member States representatives.

In 2016, the European Commission undertook a renewal of the SET Plan. For this purpose, it has prepared the position paper, which was given in a wide public debate for all members and stakeholders. An action plan is under preparation now, for which the bases are preparing by working groups. At this meeting, the group for nuclear energy made all the necessary arrangements for the European Commission to prepare an action plan.

The meeting, organized by the SET Plan secretariat in Brussels, was as the president of the ENEN attended by prof. Dr. Leon Cizelj, Head of the Reactor Engineering Division.

Invited lecture at the Nuclear 2017 conference

Pitesti, Romania, 23.-26.5.2017

The Nuclear 2017 conference, the annual conference of Romanian nuclear experts, was attended by about 200 experts, mainly from Romania. Prime Minister Sorin Grindeanu and Research Minister Serban Valeca also visited it.

At a conference held at the Romanian Nuclear Research Institute RATEN-ICN near the city of Pitesti in Romania, Prof. Dr. Leon Cizelj, Head of the Reactor Engineering Division, had an invited lecture entitled "The role of ENEN in attracting, developing and retaining nuclear talents".

Meeting of the ETSON Management Board and ETSON General Assembly

Frascati, Italy, June 25-27 2017

Nearly ten years ago, ETSON was established with the aim of professional networking of accredited nuclear and radiation safety experts working in the Member States of the European Community. During this time, our colleagues from Japan, Russia and Ukraine joined us. Members of ETSON must be authorized experts in the country in which they are registered, they must implement a long-term research program in the field of nuclear safety and must operate as a non-profit organization.

Among the most important activities of ETSON are joint research projects, exchange of experience, cooperation in the human resources development, assistance to national administrations in harmonizing nuclear safety requirements and helping to establish a nuclear safety infrastructure in the countries that are just choosing the nuclear power.

The regular semi-annual meetings of the ETSON Management Board and the ETSON General Assembly held an overview of the performed work of the association in the first half of year 2017 and outlined the work in the second half of 2017. Particular attention was paid to the consideration of strategic objectives and ways to achieve them, as well as the participation of the ETSON Management Board at the international conference Nuclear Energy for New Europe in September 2017 in Bled.

The meeting, organized by ENEA in Manchester, was attended by prof. Dr. Leon Cizelj, Head of the Reactor Engineering Division, JSI.

18. Meeting of the General Assembly of EUROfusion Culham, United Kingdom, July 13 - July 15, 2017
 

European fusion research in the frame of the Horizon 2020 are united together in the targeted 5-year (2014-2018) fusion program EUROfusion, which is under the auspices of the EURATOM Treaty. The basic objectives of the EU fusion research are related to support of the ITER fusion reactor and in the long run, towards the demonstration fusion power plant. The EUROfusion program is implemented by a consortium of 29 fusion research units of EU members, where the Jožef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The leading partner in the consortium is the Institute of Plasma Physics (IPP), Germany. The decision-making body of the consortium is the General Assembly.

On July 13 and 14, 2017, the 18th meeting of the General Assembly of EUROfusion at the Culham Center for Fusion Energy (CCFE) took place in Culham, Great Britain. The first day of the assembly was attended also by the Director of the European Agency Fusion for Energy - F4E, who presented the progress of the ITER project with an emphasis on the activities that the F4E Agency conducts with the EUROfusion consortium. The largest activities are the development of the source of the neutral particles MITICA in Padova and the ITER breeding blanket test model. Also, both European organizations work together to develop diagnostics for the Japanese tokamak JT60-SA. Among the most important points at the General Meeting, the proposal for the reorganization of the DEMO project management and the strategy for communication with the public within the framework of the EUROfusion program was presented. After the meeting, GA members visited the Joint European Torus (JET) fusion device, which is currently in the process of upgrading and preparing for the most important experimental operation with deuterium and tritium. The General Assembly meeting of the EUROfusion was attended by Dr. Boštjan Končar from the Reactor Engineering Division, JSI.

Fermi course: Leading a nuclear business. Competence development for academic teachers, Uppsala, Sweden, 29th - 30th May 2017

On 29th and 30^th of May 2017 dr. Tiselj attended a workshop for teachers in the field of education in nuclear engineering organized by INBEx (Institute for Nuclear Business Excellence) in cooperation with the ENEN (European Nuclear Education Network) association. The course was organized at the University of Uppsala by a former professor of the university and later associate of Vattenfall (owner of Swedish nuclear power plants) company and today’s INBEx Director of the Institute, Dr. Jan Blomgren.

The participants (8 teachers) divided into two independent team of operators of nuclear power plants for two days. For the period of six years, they had to provide for the efficient, safe and socially acceptable operation of the plant under the uncertain conditions of the deregulated electricity market. With confronted unexpected technical, economic and societal challenges (all based on real experiences of various plants around the world), the professors experienced the complexity of decision-making based on incomplete information and the various opinions of experts, public, regulators and employees.

According to attendee, participation in this workshop can help someone make better decisions and impact on improving communication between stakeholders in the nuclear energy industry

Spring 2017 CAMP Meeting,  Warsaw, Poland, 22.-24. 5. 2017

CAMP (Code Applications and Maintenance Program) is the largest research program conducted under the auspices of the United States federal Nuclear Regulatory Commission U.S. NRC since 1993. As part of the CAMP the development and exchange of experience on system software RELAP5 and Trace, software for neutron calculations PARCS and graphical interface SNAP took place. Based on an agreement with the U.S. NRC several administrative authorities, research organizations and industry representatives from more than 20 countries are cooperating in the CAMP program. Participants from Slovenia (JSI, Krško Nuclear Power Plant, and the Management Board of the Slovenian Nuclear Safety) are coordinated by the »Jožef Stefan« Institute.

CAMP Spring Meeting was divided into two parts, a technical and programming part. In the technical part at first were presented reports of some CAMP Member States (Belgium, Czech Republic, Croatia, Canada, Poland and Spain), which was followed by the status report on the software development of the U.S. NRC: TRACE, PARCS, RELAP5 and SNAP. In the end, the technical reports (16 in total) were presented. JSI presented a paper:

• "RELAP5 and TRACE Simulation of Hot Leg Break LOCA Experiment on LSTF" (Andrej Prošek).

Within the framework of the programming part of the meeting discussion was about the need for further development of computer programs and tools for the simulation of nuclear installations and proposals of contributions in kind, which are required for all participants in the CAMP (for Slovenia one contribution, the contribution for 2017 was already proposed at the previous meeting ). The new edition of the TRACE program is scheduled for summer 2017.

This year's spring CAMP meeting, which took place from 22. - 24. 5. 2017 in Warsaw, Poland, was organized by the Polish Agency for Atomic Energy in cooperation with the U.S. NRC. The meeting was attended by approximately 60 representatives from 16 countries, including 20 from the host country. From JSI’s Reactor Engineering Division Dr. Andrej Prošek attended the meeting.

Within the framework of the OECD (Organization for Economic Cooperation and Development) operates NEA (Nuclear Energy Agency), which, inter alia, through various projects in the field of nuclear energy enables and encourages cooperation between research organizations of member states.

NEA proposes to establish a framework NEST (Nuclear Education, Skills and Training), part of which would include projects that would aim to educate new generations of professionals in the field of nuclear energy by the interconnection of research organizations. In the context of project, (mostly) doctoral students from research organizations would spent a certain time in other organizations also involved in the project. Therefore, membership in the NEST would allow and facilitate research organizations the exchange of young professionals. NEST is designed primarily long-term and is expected to become operational in the second half of 2017 or first half of 2018. Annual contributions of membership in NEST should be of the order of 40,000 EUR, but then certain part of the cost of alliances would be also financed from these funds.

At the initial meeting, the representatives of Belgium, Canada, Czech Republic, France, Germany, Hungary, Italy, Japan, South Korea, Poland, Russian Federation, Slovakia, Slovenia, Spain, Turkey, the United Kingdom and the United States expressed the interest of the membership in NEST. Most of the representatives express interest, however we have to previously obtain the opinion of governments and stakeholders in the field of nuclear energy in our own countries. The final decision must be notified within 60 days. During this period, the JSI will inquired about the possibilities of obtaining funds for the membership in NEST among the Slovenian stakeholders.

The initial meeting of the frame NEST, hosted by OECD / NEA between 11th and 12th of May 2017 in Paris (France), was attended by Prof. Leon Cizelj as President of ENEN (European Nuclear Education Network) and Dr. Ivo Kljenak as a representative of the JSI and Slovenia.

17th EUROfusion General Assembly Meeting, Cadarache, France, 10.-12.04.2017

European fusion research under Horizon 2020 combines target-oriented 5-year (2014-2018) EUROFusion program, which takes place under the auspices of the EURATOM Treaty. The basic objectives of the EU fusion research are related to support of the ITER fusion reactor and in the long-term, the realization of demonstration fusion power plant. The EUROFusion program is performed by a consortium of fusion research units of the EU countries (in total 29), where the Jozef Stefan Institute acts as a Slovenian coordinator and partner in the consortium. The leading partner in a consortium is the Institute of Plasma Physics (IPP), Germany. Decision-making body of the consortium is General Assembly.

In the days between 10.04. and 12.04.2017 the 17th General Assembly EUROfusion Meeting was held in Cadarache, France, organized by CEA (Le Commissariat à l’énergie atomique et aux énergies alternatives). At the meeting we discussed and approved the revised EUROfusion program budget for the year 2017, which this time includes funds for the implementation of the experimental campaigns on smaller tokamaks, funding for education and training programs and resources for the "Enabling Research" projects. The General Meeting approved the first phase of the PEX (Plasma exhaust) program. We have acquainted the contents of the second phase of the PEX program, at which point a controversial debate was developed on the classification of the Italian proposal for a new fusion device for testing alternative divertor configuration DTT (Divertor Test Tokamak). The second day of the meeting was devoted to a discussion with the director of ITER, Mr. Bigot. He presented to the Assembly the current status of the construction of the experimental reactor. The discussion was intended primarily for more effective cooperation between EUROfusion program and the ITER organization. For this purpose, a new proposal for the coordination and integration between EUROfusion activities directly related to the ITER was presented. Members of the GA visited the construction site of ITER and production facility of the poloidal superconducting magnets and cryostat assembly components, where the production of technological components is already underway. EUROfusion General Assembly Meeting was attended by Dr. Boštjan Končar from the Reactor Engineering Division, JSI.

OECD-NEA PIRT for SFP in LOCA, Pariz (Francija), 03-05.04.2017 

Nuclear Energy Agency (NEA), which operates within the Organization for Economic Cooperation and Development (OECD) has currently 29 member countries and was established on 1 February 1958. The main mission of the agency is to assist its members in the conservation and development of the environment, which will offer the scientific, technological and legal basis for the safe, environmentally friendly and economically justified use of nuclear energy for peaceful purposes through international cooperation. Another important role of the agency is to create a credible assessments and responses to key questions about nuclear energy and to provide support to individual member governments in the decisions that are related to nuclear energy policy.

On the Fukushima events, the Committee on the Safety of Nuclear Installations (CSNI), which operates within the NEA, responded with a variety of activities in support of the adoption of the new decisions. The result of one of these activities was the preparation of the report "Status Report on Spent Fuel Pools Under Loss-of-Cooling and Loss-of-Coolant Accident Conditions," which summarizes current knowledge about such accidents. The report recommends implementing a methodology Phenomena Identification and Ranking Table (PIRT) in order to systematically identify the events, which are of great importance to nuclear safety and on which the available knowledge is inadequate.  It is a methodology that in the first phase identifies key events related to a particular topic, so SFP, and in the second phase, based on the vote of the group of experts of the workgroup members, identifies the importance of individual phenomena and evaluates the reliability of the voting results, thus enabling the creation of priorities for further consideration. JSI has joined the workgroup only in the second phase of the report preparation.

The first day of the meeting, the discussion was about the second PIRT report draft, which already represents a solid approximation of the final report. On the second day, we focused on the selection and evaluation of identified phenomena, which for the case of an incident with a loss of cooling and / or loss of coolant require priority attention. On the third day, we focused on open issues, conclusions and recommendations and we prepared a time plan for further work.

The fourth final workgroup meeting, which was organized by the IRSN on 3-5.4.2017 at the OECD conference center in Paris, was attended by Reactor Engineering division associate dr. Marko Matkovič. At the meeting there were 23 registered and nominated representatives of various organizations.

Meeting of European MELCOR users, Madrid, Spain, 6-7.4.2017

After the severe accident in the Fukushima nuclear plant, standards for nuclear safety have tightened. Thus, the analysis of severe accidents are becoming an integral part of the safety reports. For independent verification of analyses of severe accidents MELCOR computer program is uses in the world primarily. It can be obtained by participating in the U.S. NRC international research program CSARP (Severe Accident Research Cooperative Program). Slovenia is a member of the program CSARP since the end of 2015 and  has already cooperate in the years 1998-2005. As part of the CSARP research program place, a joint meeting CSARP / MCAP (MELCOR Code Assessment Program) is in the US every year. Due to the prevalence of the program, a regional annual meeting of the European (EMUGE - European MELCOR User Group) and Asian (AMUG - Asian MELCOR user Group) MELCOR users has been held for several years. The first annual meeting EMUGE was organized in 2008 at the Paul Scherrer Institut in Switzerland.

EMUGE ninth meeting was held at the CIEMAT in Madrid between the 6th and 7th April 2017. It was attended by 42 users and developers of the MELCOR from 14 European countries and the USA. The meeting was divided into five sections, in which developers and users of the program presented their activities:

• Introductory presentations,
• Development and application of models,
• Experiments and application for the gas-cooled fast reactor,
• Application for the light-water reactors
• Fusion applications.

 Participants also viewed the PECA experimental device dedicated to aerosols behaviour. The meeting was attended by Dr. Matjaž Leskovar from Reactor Engineering Division from the Jožef Stefan Institute, who is the Slovenian coordinator for cooperation in the framework of the CSARP research program.

ENEN Management Board and General Assembly Meeting, Manchester, United Kingdom, 28.2.-03.04.2017

More than 60 members of the ENEN Association represents the majority of European universities and research institutes providing education in the field of safe use of nuclear energy. In more than a decade of existence, the association succeeded developing standard curricula, mutual recognition of ECTS points, relatively extensive exchange of students and teachers and a number of pilot schemes for training.

Management Board (2.3.) focused primarily on preparations for the association’s electoral assembly, which followed 3.3. The General Assembly accepted the report for year 2016 and plans for 2017. Again were elected the president - prof. dr. Leon Cizelj – and vice-president - prof. dr. Filip Tuomisto – with one-year term.

Before the Management Board meeting with the help of representatives of the IAEA work meeting with the presidents of regional networks for nuclear education was carried out: dr. Youngmi Nam (ANENT), prof. Aucyone da Silva (LANENT), prof. Andrey Kosilov (STAR-NET), and Professor. Kenji Takeshita (JUNET-GNHRD). After the General Assembly a work meeting of the European project EUJEP-2 was carried out.

Management Board meeting, General Assembly and other supporting events that took place in the University of Manchester, UK, were attended by prof. Leon Cizelj, head of the Reactor Engineering Division.

NUGENIA Forum and General Assembly, Amsterdam, 27.-29.3.2017

NUGENIA (Nuclear Generation II & III Association) is an organization that brings together (mostly) European stakeholders in the field of nuclear energy: research and technical-safety organizations and managers and producers of nuclear power plants. NUGENIA was officially founded in 2011. The main purpose of the organization should be directing and coordinating research in the field of nuclear energy. System is that smaller groups are proposing the project on the NUGENIA website with a brief overview of the project itself. Other NUGENIA members then have the opportunity to express an interest in participating. In addition, project proposals, which will be confirmed as eligible by NUGENIA, should have a greater chance of a successful application to the calls of the European Commission.

The General Assembly has formally closed associations business in 2016 and outlined the main points of the program in 2017. They have also elected new members of the Executive Committee.

The Forum, which was attended by about 150 people this year, presented to the participants in three parallel sessions the already done work in the funded projects by the NUGENIA Association portfolio and, of course, preparations for new projects.

General Assembly and NUGENIA Forum was attended by Prof. Dr. Leon Cizelj, head of the Reactor Engineering Division.

EUROSAFE Conference Program Committee, meeting with Mr. William Magwodom, Director of the OECD / NEA

Paris, France, 31.1.-2.2.2017

The EUROSAFE FORUM conference is organized each year by the three major European organizations for scientific and technical support to the nuclear regulatory authorities: French IRSN, German GRS and Belgian BelV. The conference is scheduled to take place on 6 and 7.11. in Paris.

Program Committee meeting was devoted to defining the basic program of the conference and some innovations in the form and content of the conference.

Attendance at the meeting of the EUROSAFE Conference Program Committee was also an oportunity for Prof.Dr. Leon Cizelj as the President of the ENEN Association for a conversation with Mr. William Magwoodom, Director of the OECD / NEA. Prof. dr. Leon Cizelj also met Mr. Philippe Correa, Director of the Institut national des sciences et techniques nucléaires (INSTN), which operates within the CEA.

The meeting of the EUROSAFE FORUM 2017 Conference Program Committee, which was organized by the French member of ETSON, IRSN, was attended by Prof.Dr. Leon Cizelj, head of the Reactor Engineering Division.

SAFETY CULTURE NUSHARE WORSHOP, Madrid, Spain, 24-17.1.2017

NUSHARE project is aimed at raising awareness and educating decision-makers about nuclear safety culture. It is designed for three categories of decision-makers: politicians and opinion leaders, regulatory authorities and technical support organizations and operators and power plants suppliers.

This workshop was intended for experts of nuclear regulatory body and authorized experts for radiation and nuclear safety. The most important content was support for the interpretation and understanding of nuclear safety culture to the general public and simulation of management of nuclear power plants. In the management of nuclear power plants simulations the workshop participants formed Management Boards with few members and then with decisions about carried and non-carried out investments and reactions to minor defects or irregularities in our facilities verified what consequences could our management and decision-making strategies have after several years of operation.

The workshop, organized by the ENEN Association on the premises of the Consejo de Seguridad Nuclear in Madrid, was attended by prof. Leon Cizelj, head of the Reactor Engineering Division in the role of President of ENEN.

MITHYGENE-ETSON hydrogen deflagration benchmark kickoff meeting, Orleans, France, 21/03/2017

Within the French project MITHYGENE active from 2013, with ETSON members joined, an experimental device ENACCEF2 was designed and built that offers unique opportunities to study the acceleration, deceleration and choking of flames. Some hydrogen combustion experiments carried out within the project will be used as combustion benchmark for a comparative study of computational codes used in safety analyses of hydrogen combustion in the containments of nuclear power plants. ETSON is the European Association of authorized experts for nuclear (and radiation) safety. Within the association several working groups and committees are operating.

At the initial meeting the cooperating partners dealt with the details of planned experiments, one of which will be open and the results of two experiments will be available after delivered results of simulations, and experimental devices ENACCEF2 itself, which was also visited. Participating partners presented computational codes, which they intend to use. The timeframes of a comparative study were also presented, in which the calculations of open experiments with the before known experimental results will be followed by the blind tests calculations without experimental results. Next meeting, at which calculations and comparison of the results of the first phase will be presented, is scheduled for the end of May or beginning of June 2017.

Kickoff meeting for MITHYGENE-ETSON combustion benchmark, which was in collaboration with the IRSN hosted at ICARE from the CNRS, took place in Orleans, on the March 21^st 2017. Tadej Holler from the "Jožef Stefan" Institute’s Reactor Engineering Division attended the meeting.

4^th NUGENIA-SARNET TA2 review meetings on in- and ex-vessel corium behaviour, Puerto de la Cruz, Spain, 2.3.-10.3.2017

NUGENIA (NUclear GENeration II & III Association) is an association dedicated to the research and development of nuclear fission technologies, with a focus on Generation II and III nuclear plants. It gathers stakeholders from industry, research, safety organisations and academia, committed to develop joint R&D projects in the field. NUGENIA builds on the past success of European Commission-supported networks SARNET, NULIFE and SNETP. The work of NUGENIA is organised in seven technical areas, within a general scope defined by the Strategic Research Agenda published by SNETP, the European stakeholder forum for nuclear technology.

The NUGENIA Review Meeting was for technical area 2 “Severe Accidents” and was devoted to sub-areas TA2.1 “In-vessel corium and debris coolability” and TA2.2 “Ex-vessel corium interactions and coolability”. At the meeting the partners presented the status of current research activities and future plans, and proposals for future projects were presented and discussed. A special session was devoted to the 7.FP EU IVMR (In-Vessel Melt Retention Severe Accident Management Strategy for Existing and Future NPPs) project.

The review meeting was jointly organized by KIT from Germany and CEA from France in Puerto de la Cruz in Spain from 2.3.-10.3.2017. It was attended by Dr. Matjaž Leskovar from the Reactor Engineering Division of the Jožef Stefan Institute (JSI-R4). He had a presentation entitled:

Leskovar, T. Skobe: “Analysis of Oxidation Influence in Ex-Vessel Steam Explosion with Metal Corium + Current status of JSI FCI R&D and FCI topics that JSI considers important in future”.

SESAME project is a project in the context of the European project Horizon 2020. The three main objectives of the project are: development and validation of advanced numerical approaches for the design and safety evaluation of advanced reactors; achievement of a new or extended validation base by creation of new reference data; and establishment of best practice guidelines, verification and validation methodologies, and uncertainty quantification methods. Project results are expected to be used in the design and improvement of fourth generation reactors. Explicitly exposed were the reactor ASTRID, MYRRHA, ALFRED and SEALER. The project is divided into 7 work packages. 23 organizations from the European Union and 2 organizations from the United States are cooperating.

In the first part of the meeting, organizations preparing experimental facilities (under any of the work package) presented the progress in production and measurements. The second part of the meeting began the following day. Participants were divided into two groups for the work packages 1 and 2 and for the work packages 3 and 5. In the third part of the meeting, which began on the third day, the participants met again together for the packages 6 and 7. The first one is dedicated for the learning materials for the simulation of fluid mechanics preparation, the other for the project administration. Later the Project Management Board was held, followed by General Assembly of the project. On the latter, payments, certain changes regarding the financing of certain partners and changes that allow cooperation with American partners have been agreed.

The meeting was held from 6. to 8. March in the premises of the NRG organization in Petten, Netherlands. The meeting as a representative of the Reactor Engineering Division attended Jure Oder. At a meeting of the work package 1: Fluctuation and vibration he presented the results achieved in the last six months.

Workgroup WP5 Soteria project meeting, EDF Lab Les Renardières, France, March 6. - 8. 2017

SOTERIA project (»Safe long term operation of light water reactors based on improved understanding of radiation effects in nuclear structural materials«) is a four-year European project, which began on September 1st 2015 under the auspices of the EURATOM program Horizon 2020. The main objective of the project is to improve understanding of the aging phenomena of steels, which are used for the pressurized water reactor vessels and its internal components. With the research in the field of steel aging regulators and operators will have key information required for safe and long-term operation of the existing European nuclear power plants. The project involves a number of European research centres (including JSI) as well as industrial partners. The project coordinator is CEA, France.

At the Workgroup WP5 meeting, which deals with the modelling and simulations, the results of the work in the first 18 months of the project were presented. JSI is involved in:

• development of a crystal plasticity model for mechanical description of stainless steels irradiated with neutrons and,
• modelling of intergranular boundaries, to simulate the formation of early damage or cracks.

At the meeting the JSI, together with IRSN and CNRS presented a comparison of the two methods - the finite element method and the Fast Fourier Transform method - in the case of tensile stress of irradiated polycrystalline aggregate. The title of the presentation was: »Polycrystalline simulations of irradiated stainless steel: FEM versus FFT«.

The meeting in Les Renardierès was organized by EDF from March 6. - 8. 2017 and was attended by Dr. Samir El Shawish from the Institute "Jozef Stefan" Reactor Engineering Division.

6th International Symposium and Seminar on Global Human Resource Development for Safety, Security and Safeguards, Tokyo Institute of Technology, Tokyo, Japan

The 6th International Symposium and Seminar on Global Human Resource Development for Nuclear Safety, Security and Safeguards is a traditional event that was held by Tokyo Institute of Technology in the framework of Academy for Global Nuclear Safety and Security Agent project with cooperation of International Atomic Energy Agency (IAEA), World Nuclear University (WNU), European Nuclear Education Network (ENEN), University A&M Texas, Japan Atomic Energy Agency (JAEA) and Institute of Nuclear Materials Management (INMM) Japan. This event took place from February 20th to March 3. 2017 on the Tokyo Institute of Technology in Tokyo, Japan. Academy for Global Nuclear Safety and Security Agent Management Board started with the seminar on 15. 2. 2017.

The event is intended primarily for networking of international students from Academy for Global Nuclear Safety and Security Agent with students and professors from recognized universities in the world as well as Japanese of national and international nuclear organizations decision-makers.

International Symposium and Seminar was divided into three parts. In the first public part, which took place from February 20th to 22nd 2017 plenary session were conducted with lectures of representatives of different international and Japanese institutions, which work in the field of the nuclear energy. The second part of the seminar included a visit to Hiroshima University, Radiation Effects Research Foundation (RERF), Hiroshima Peace Memorial Museum and MONJU Fast Breeder reactor. From 28.2. to 03.03.2017 for the public closed part of the seminar with lectures of representatives of Japanese corporations and professors from the Tokyo Institute of Technology.

Lectures topic were reports of the accident at Fukushima Daiichi, the future of nuclear energy, education in the field of nuclear energy, severe accidents in nuclear power plants, the safety assessment and decision-making in the event of accidents and safety improvements in future nuclear power plants.

The symposium was attended by 27 students and young researchers from different countries. From the Jožef Stefan Institute the seminar was attended by Rok Krpan from the Reactor Engineering Division (R4). First part of the seminar was attended also by prof. Leon Cizelj, head of the Reactor Engineering Division in the role of President of ENEN, which during the days before the seminar participated in the Management Board of "Academy for Global Nuclear Safety and Security Agent".

The international symposium and seminar on global nuclear human resource development for safety, security and safeguards (IS3S) is a yearly activity coordinated by the Academy for Global Nuclear Safety and Security Agent of the Tokyo Institute of Technology. The aim of this activity is to enhance the international relations of students and young professionals in the nuclear field (Japanese and foreign). The IS3S is organized within the program of nuclear studies of the Academy which aims at developing nuclear human resources in the fields of safety, security and safeguards (non-proliferation), i.e. to develop global leaders with a scientific background in the nuclear physics and engineering fields which are able to tackle global issues, efficiently communicate with the society as well as with peers in the international nuclear community.

The 5^th IS3S was divided in three parts. Four (4) plenary sessions were delivered in 3 days including 27 speeches by renowned nuclear department heads of universities worldwide and international and domestic nuclear agencies. The topics of the plenary sessions included nuclear energy in the future and non-proliferation issues, nuclear education and training and nuclear research and development. In the following 4 days, field education activities were carried out such as radiation level measurements in Tokyo and in the Fukushima prefecture area and visits to the Rokkasho reprocessing plant and the Onagawa nuclear power plant. Back into Tokyo, the seminar continued with 4 lecture sessions delivered in 2 days by 9 prominent professionals in the fields of safeguards systems, nuclear security culture, nuclear terrorism and forensics as well as cyber security of nuclear facilities. The last two days of the seminar were dedicated to student sessions where groups of students and young professionals prepared oral presentations of topics lectured during the symposium and seminar.

Forty-seven (47) students and young professional were invited to the 5^th IS3S-5. The students came from the Academy (12), the TokyoTec nuclear engineering program (3), Japanese young professionals from national agencies and electric companies (6) and overseas students and young professionals (26) from USA (8), Malaysia (5), Korea (3), Vietnam (2), Russia (2), Lithuania (2), Austria (1), Romania (1) and Slovenia (1). Oriol Costa was the Slovenian representative in the 5^th IS3S, held during February 21^st and March 3^rd. The European representatives were selected through the European Nuclear Education Network.

ASAMPSA_E (Advanced Safety Assessment : Extended PSA) is a 3 years European project within EC 7th framework programme (FP7) dedicated to the assessment of the consequences of combination of extreme external events on the safety of Nuclear Power Plants.

The Fukushima nuclear accident in Japan resulted from the combination of two correlated extreme external events (earthquake and tsunami). The consequences (flooding in particular) went beyond what was considered in the initial NPP design. The project ASAMPSA_E aims at identifying good practices for the identification of such events with the help of Level 1 and Level 2 PSA and for the definition of appropriate criteria for decision making in the European context. The Jožef Stefan Institute is contributing to five out of six work packages within the project.

The ASAMPSA_E Technical Meeting was held in Vienna during the 08-12 September 2014, and dr. Andrija Volkanovski attended it. The meeting was hosted by the University of Vienna. The purpose of the meeting was to specify the content of deliverables and the distribution of work in WP21 (Initiating events modelling), WP22 (Introduction of hazards in Level 1 PSA and WP3 (General issues regarding extended PSA). The representatives of project beneficiaries were present on the meeting. Participants from JANSI(Japan) and NRC(USA) were present on the meeting and made presentations on developments considering introduction of external hazards in PSA.

MULTIMETAL (Structural performance of multi-metal component) is a 3 years European project within EC 7^th framework programme (FP7) dedicated to the integrity assessment of dissimilar metal welds, i.e., welds that join components made out of different kind of steels in nuclear power plants primary systems.

The project includes an important mechanical and fracture testing campaign of specimens containing dissimilar metal welds with the aim to characterize properties’ gradients along the weld. Three different mock-ups, of characteristic dissimilar welds in European power plants, have been fabricated but testing of the second mock-up specimens has just started. This mock-up was delivered with 10 months delay affecting a considerable number of related project deliverables. The project is currently in the 29^th month. Project partners wish to ask for a 1 year extension of the project and important efforts are currently dedicated to catch up with the project   initial schedule. Numerical simulations of homogenous (one material) fracture specimens were successfully performed. Now, new matrices of 2D and 3D simulations of heterogeneous (weld) specimens of mock-ups 1 and 3 have been set up and a new Round Robin exercise will compare results among partners and numerical codes used to perform the finite element calculations. IJS-R4 is   involved in four different work packages within MULTIMETAL project, mainly related to numerical simulations, and is leading the one dealing with training, mobility and knowledge management.

The 6^th Executive Committee Meeting of project MULTMETAL was held in Studsvik, Sweden during June 12^th and 13^th,2014 and Oriol Costa attended it. The host institution was Studsvik (STU) and participants came from AREVA GmbH (Germany), AREVA NP SAS (France), VTT (Finland), EDF-Energy (UK), EDF-R&D (France), JRC (The Nederland), BZF (Hungary), CEA (France) and IJS (Slovenia).

NUGENIA (NUclear GENeration II & III Association) is an association dedicated to the research and development of nuclear fission technologies, with a focus on Generation II and III nuclear plants. It gathers stakeholders from industry, research, safety organisations and academia, committed to develop joint R&D projects in the field. NUGENIA builds on the past success of European Commission-supported networks SARNET, NULIFE and SNETP. The work of NUGENIA is organised in seven technical areas, within a general scope defined by the Strategic Research Agenda published by SNETP, the European stakeholder forum for nuclear technology.

The NUGENIA Review Meeting was for technical area 2 “Severe Accidents” and was devoted to sub-areas TA2.1 “In-vessel corium and debris coolability” and TA2.2 “Ex-vessel corium interactions and coolability”. At the meeting the partners presented the status of current research activities and future plans, and proposals for NUGENIA and HORIZON 2020 were presented and discussed.

The review meeting was jointly organized by KIT from Germany and CEA from France in Santa Cruz de Tenerife in Spain from 17.-21.2.2014. It was attended by Dr. Matjaž Leskovar from the Reactor Engineering Division of the Jožef Stefan Institute (R4 JSI). He presented the status of fuel-coolant interaction (FCI) activities at R4 JSI and gave a technical presentation entitled: M. Leskovar, V. Centrih, “Influence of Zirconium Content on Steam Explosion Energetics – Comparison of SERENA and ZREX experiments”. The partners agreed to prepare two FCI related project proposals, one for NUGENIA+ and one for HORIZON 2020, with R4 JSI participating.    

On June 21st 2013 Jožef Stefan Institute conferred the title Emeritus Scientist of the Jožef Stefan Institute to three former employees of the Institute.

The titles were conferred for important merits in the field of research and education and for the transfer of knowledge to younger generations of researchers. Following the conclusions of the Scientific Council of the Institute this award was presented to the founder and long-time head of Reactor Engineering Division prof. dr. Borut Mavko.

The award was also conferred to prof. dr. Boris Žemva and prof. dr. Raša Pirc.

The International Atomic Energy Agency (IAEA) has been organizing a series of technical meetings on the topic of Best Estimate approach in licensing-type safety analysis. The main purpose of these meetings is to provide an international forum for exchanging results and discussing the current issues related to the use of Best Estimate plus Uncertainty (BEPU) approach in safety analysis. More specifically, the focus is set on deterministic safety analysis using BEPU and on probabilistic safety analysis.

The latest IAEA Technical Meeting on BEPU Methods in Safety Analysis was organized by the IAEA together with the San Piero a Grado Nuclear Research Group (GRNSPG). The participants that attended the meeting represented 18 countries, thus providing a good opportunity to exchange experience and compare national practices related to accident analysis. The agenda of the meeting consisted of national presentations, discussions, and working group sessions focusing on the key issues of applying the BEPU methodology for plant licensing. During this technical meeting, a visit was organized to the GRNSPG headquarters, where the Nuclear Power Plant Technology Knowledge Management System (NUTEMA) facility was presented and a short demonstration was given. The goal of the NUTEMA project is to develop an integrated system that is capable of managing the knowledge required for nuclear power plant design, licensing, operation and safety.

The technical meeting concluded with a session presenting the working groups recommendations and proposals for future actions regarding the application of BEPU methodology for licensing safety analysis.

The meeting was held in Pisa, Italy, during the period of 10^th-14^th June, 2013, and was attended by Ovidiu-Adrian Berar.