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If China’s experimental reactor is a success it could lead to commercialization and help the nation meet its climate goals. If China’s experimental reactor is a success it could lead to commercialization and help the nation meet its climate goals.

Nuclear power’s role as a reliable, baseload, low-carbon source and its importance in achieving clean energy goals are being increasingly recognized with growing urgency around decarbonization of the global energy systems. However, to deliver a long-term sustainable solution, it is essential to develop innovative nuclear technologies for improving the fuel utilization and reducing the nuclear waste disposal challenge. Zero Power Reactors (ZPR) are an essential initial step for developing new nuclear technologies because they allow for testing and refinement in a safe environment before large-scale deployment. This paper discusses the design of a ZPR experiments for the development of iMAGINE, a novel chloride-based molten salt reactor technology. The paper presents a detailed analysis of the neutronic design for the shutdown and control systems of an experimental ZPR based on the iMAGINE molten salt reactor technology. The study concludes that a split-core design with a lower corner reflector as an extension of the lower annular reflector offers the most robust ZPR configuration, offering optimum operational margins and maneuverability. This design ensures safety, regulatory compliance, and sufficient control and shutdown performance for the successful development of the iMAGINE technology.

The Crab (Calibrated nuclear Recoils for Accurate Bolometry) project aims to precisely characterize the response of cryogenic detectors to sub-keV nuclear recoils of direct interest for coherent neutrino-nucleus scattering and dark matter search experiments. The Crab method relies on the radiative capture of thermal neutrons in the target detector, resulting in a nuclear recoil with a well-defined energy. We present a new experimental setup installed at the TRIGA Mark-II reactor at Atominstitut (Vienna), providing a low intensity beam of thermal neutrons sent to the target cryogenic detector mounted inside a wet dilution refrigerator Kelvinox 100. After the presentation of all components of the setup we report the analysis of first commissioning data with CaWO 4 detectors of the Nucleus experiment. They show stable operation of the cryostat and detectors on a week-scale. Due to an energy resolution currently limited to 20 eV we use neutron beam induced events at high energy, in the 10 to 100 keV range, to demonstrate the excellent agreement between the data and simulation and the accurate understanding of external background. Thanks to these data we also propose an updated decay scheme of the low-lying excited states of 187 W. Finally, we present the first evidence of neutron-capture induced coincidences between BaF 2 γ -detectors installed around the dewar and the inner cryogenic detector. These promising results pave the way for an extensive physics program with various detector materials, like CaWO 4 , Al 2 O 3 , Ge and Si.

The work aims to develop a monitor that tracks structural changes in materials as they occur. Long-term on-line measurement of such changes is useful in the nuclear power engineering, where reactor vessel materials are subjected to intense neutron irradiation and embrittle with prolonged irradiation. This paper describes studies where a tension of the order of tensile strength is applied to a wire-shaped specimen so that the wire material undergoes plastic deformation. A short current pulse is then applied through the wire, which causes embrittlement of the wire. Both processes are measured by means of changes in the natural frequency of a pre-tensioned wire, which serves as a test sample. Experimental results are presented for different ratios of wire pre-tension and short pulse energy, as well as for their cyclic repetition.

Background: Thurso/Caithness in the United Kingdom has gone through a lot of changes and transitions in the last decades. The decision to build a nuclear reactor test facility in the 1950’s in Dounreay/Caithness UK, as well as the current phase of decommissioning impacted not only the technology development but also the social fabric of the community and individuals within it. This study aimed to explore the lived experiences of people impacted by the nuclear project at Dounreay. The results will form the basis for the discussion about locating future experimental or development facilities, possibly at historic sites. This study employed an exploratory qualitative research approach based on the constructivist grounded theory methodology. Constructivist grounded theory applies a systematic, inductive, iterative, and comparative approach to investigate the meanings behind people’s experiences. It was chosen as the method to explore an under-researched area: the host community for nuclear research in Thurso/Caithness. Purposeful snowball sampling from March 2023 till November 2023 through gatekeepers, media and social media was used. 19 participants including 10 women and 9 men in the age range 36–71 took part. The semi-structured interviews were conducted via phone or online platforms. Participants fondly recalled the hey-day when the Dounreay site was built and the population increased rapidly. They shared memories of how the town of Thurso/Caithness was thriving then which had a huge impact on individuals’ opportunities to receive a very good education, earn a good salary, indirect benefits beyond the nuclear project, and a cosmopolitan sense of community. However, the changes over time and the process of decommissioning had more complex implications for individuals as well as for the community. The work opportunities are still favourable. However, this study also highlights new challenges such as decaying infrastructure, a lack of hope of prosperity, and a feeling of being forgotten. This unique study highlights how a politically driven project impacts a community fundamentally. We identified two themes: mostly positive nostalgic views and Changes and Challenges for the community.

The nuclear power system has faced a challenging issue of significantly improving the characteristics of nuclear fuel breeding while maximizing the advantages of the technology of vessel-type pressurized water reactors used extensively in nuclear power. This is possible via switching to supercritical coolant parameters. An increase in production of fissile nuclides, as compared with traditional pressurized water reactors, is achieved by switching to a harder neutron spectrum due to reducing greatly the coolant density and using a dense fuel lattice. A necessary condition for the VVER-SKD design development is the establishment of an experimental base. A multipurpose test research reactor, MTRR-SCW, is the potential testing ground for the reactor technology, and for new structural and fuel materials and fuel rods. The paper presents the key characteristics of the MTRR-SCW reactor, as well as the potential MTRR-SCW applications at different stages of its operation (testing and research). A concept is proposed at the initial stage for the reactor phased rise to power, which will make it possible to justify the efficiency of the MTRR-SCW fuel with increased linear loads through experiments in the independent central loop channel. This concept also involves phased validation and study of the joint operation of the reactor plant and the steam turbine plant as part of the MTRR-SCW nuclear power plant. At the research stage of operation, safe operating limits need to be determined, and the choice of normal operating modes for the VVER-SKD power reactor justified, and experimental studies need to be undertaken to investigate the behavior of structural materials and fuel compositions as part of experimental fuel rods for the advanced light-water reactor cores with different neutron spectra. Long-term irradiation of experimental fuel rods is planned to be carried out in the MTRR-SCW’s independent peripheral loop channel, and experimental simulation of emergency processes to be performed in the reactor’s central loop channel. This paper deals with the issues to be addressed prior to starting the VVER-SKD power reactor design. Issues have been identified that can be fully or partially solved at effective facilities, as well as the applications for the MTRR-SCW prototype reactor. The paper presents the key characteristics of the MTRR-SCW reactor, and describes in detail the concept for the phased development of the research reactor capabilities and phased rise to power.

The failure mode of the nuclear reactor main pipeline is often the first break and then leakage, i.e., Leak-Before-Break (LBB). If the LBB analysis technique of the pipeline is used in the design, the double-end shear fracture accident of the pipeline can be avoided. In this paper, it is assumed that an annular penetration crack already exists in the pipeline, and the tip-opening displacement of the crack and the leakage rate of the pipeline under high pressure are calculated by using LBB theoretical analysis. Then, according to the assumed conditions, the LBB test design of the pipeline under high pressure is carried out, and the crack tip opening displacement δ and the leakage rate Q of the pipeline under high pressure are measured through the experiments.

Results of experiments to test the modes of plutonium and neptunium displacement re-extraction with a nitrate solution of uranium (VI) are presented. The developed method of plutonium displacement re-extraction was tested at the refining extraction and crystallization facility of JSC SChC as part of the comprehensive program “Development of equipment, technologies, and scientific research in the field of nuclear energy use in the Russian Federation”. Due to a high accumulation of plutonium in the fuel of fast reactors, the main task of plutonium re-extraction consists in ensuring the re-extract ratio of Pu / (Pu + U) specified by the manufacturers of oxide fuel. According to the results of the performed tests, the developed method of plutonium displacement re-extraction with a solution of uranyl (VI) nitrate allows uranium, plutonium, and neptunium to be re-extracted in the ratio specified by fuel manufacturers. In this case, the completeness of plutonium extraction into the re-extract and its purification according to the proposed method are comparable to the results obtained in the process of reductive plutonium re-extraction.

This study presents an in-depth analysis of the polonium evaporation from high-energy and high-intensity proton-irradiated liquid lead-bismuth eutectic. The applied experimental conditions closely mimic those encountered within an accelerator-driven nuclear reactor, particularly focusing on the interaction of other impurities with polonium. Utilizing proton-irradiated lead-bismuth eutectic with an impurity spectrum similar to that of a real reactor, this research establishes reliable data for the polonium evaporation in the presence of said impurities, employing the transpiration method. The results agree well with those of prior model experiments using pure lead-bismuth eutectic. This indicates that the other coexisting impurities have a negligible impact on the polonium evaporation. The good agreement of the experimental values with literature data emphasizes the reliability of the applied methods and the robustness of the current understanding. These findings have significant implications for the operation and safety assessment of heavy metal-cooled nuclear reactors and support the advancement of Generation IV accelerator-driven systems.

Several neutron sources are available at Research Centre Řež (CVŘ) that are usable in neutron physics and radioanalytical measurements, namely two experimental nuclear reactors—a ‘zero’ power (maximum 5 kW) LR-0 reactor and a medium power (maximum 10 MW) LVR-15 reactor, a 252 Cf source and a D–T generator of fast neutrons. Their basic parameters and modes of applications in various fields of science and technology are described. The reactors and other neutron sources are equipped with a number of gamma-ray (mostly High Purity Germanium (HPGe)), and neutron spectrometers to allow for assay of studied materials. Most of the above facilities are available in an open-access regime.