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Kawamura, Sho; Kikuchi, Masanobu; Hosoya, Toshiaki
JAEA-Technology 2021-041, 103 Pages, 2023/02
JAEA-Technology-2021-041.pdf:8.7MB
In response to new regulatory standard for research and test reactor which is enforced December 2013, JRR-3 got license in November 2018 by formulate new design basis ground motion. After that we evaluated for insertion property of control rod using that new design basis ground motion, and that evaluation results were accepted as approval of the design and construction method by Nuclear Regulation Authority. Now, we re-evaluated to insertion property of control rod about neutron absorber and follower fuel element by time history response analysis method. In this report, it shows that new results have sufficiency of margin compared with the past results that are accepted as approval of the design and construction method.
Collaborative Laboratories for Advanced Decommissioning Science; University of Fukui*
JAEA-Review 2022-046, 108 Pages, 2023/01
JAEA-Review-2022-046.pdf:6.25MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2021, this report summarizes the research results of the "Clarification of debris formation conditions on the basis of the sampling data and experimental study using simulated fuel debris and reinforcement of the analytical results of severe accident scenario" conducted in FY2021. The research on fuel debris so far is based on TMI-2 accident that is typical PWR accident but resent scenario analysis of sever accident progression and sampling data of the in reactor materials predict that fuel debris is diversity and piled up complicatedly depending on the unit and in reactor position. We are necessary to presume the thermodynamic condition of fuel debris during the accident in order to estimate accumulation state of debris. However the Forward analysis cannot explain
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*
JAEA-Review 2022-043, 52 Pages, 2023/01
JAEA-Review-2022-043.pdf:3.48MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2021, this report summarizes the research results of the "Fuel debris criticality analysis technology using non-contact measurement method" conducted in FY2021. The purpose of research was to improve the fuel debris criticality analysis technology using non-contact measurement method by the development of the fuel debris criticality characteristics measurement system and the multi-region integral kinetic analysis code. It was performed by Tokyo Institute of Technology (Tokyo Tech), National Institute of Advanced Industrial Science and Technology (AIST), and National Research Nuclear University (MEPhI) as the first year of four years research project. For the criticality characteristic measurement systems to be developed by the Japanese and Russian sides, both Japanese
Collaborative Laboratories for Advanced Decommissioning Science; Hokkaido University*
JAEA-Review 2022-038, 102 Pages, 2023/01
JAEA-Review-2022-038.pdf:4.76MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2020, this report summarizes the research results of the "Study on rational treatment/disposal of contaminated concrete waste considering leaching alteration" conducted in FY2021. The present study aims to understand migration behaviors of radionuclides in relation to the properties of concrete altered by leaching, to develop a model to predict concentration profiles, and to analyze waste management scenarios, with a focus on underground concrete structures in contact with contaminated water. Migration behaviors depend on radionuclides and their chemical species. Sorption of I
is less significant on C-S-H and C-A-S-H than on hardened cement paste with two orders of magnitude smaller distribution coefficient 
, while of U was the same and high around
HPC Technology Promotion Office
JAEA-Review 2022-035, 219 Pages, 2023/01
JAEA-Review-2022-035.pdf:10.94MB
Japan Atomic Energy Agency (JAEA) conducts research and development (R&D) in various fields related to nuclear power as a comprehensive institution of nuclear energy R&Ds, and utilizes computational science and technology in many activities. As shown in the fact that about 20 percent of papers published by JAEA are concerned with R&D using computational science, the supercomputer system of JAEA has become an important infrastructure to support computational science and technology. In FY2021, the system was used for R&D aiming to restore Fukushima (environmental recovery and nuclear installation decommissioning) as a priority issue, as well as for JAEA's major projects such as research and development of fast reactor cycle technology, research for safety improvement in the field of nuclear energy, and basic nuclear science and engineering research. This report presents a great number of R&D results accomplished by using the system in FY2021, as well as user support, operational records and overviews of the system, and so on.
Collaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2022-034, 135 Pages, 2023/01
JAEA-Review-2022-034.pdf:8.5MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F), Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of extremely small amount analysis technology for fuel debris analysis" conducted in FY2021. Understanding the properties of fuel debris is necessary for handling, criticality control, storage control, etc. A key technique is the chemical analysis of actinide nuclides. We develop sample pretreatment technology and separation / analysis process required for chemical analysis. The purpose of this study is to streamline future planned fuel debris analysis. To promote 1F decommissioning, we will train human resources through on-the-job training. In particular, we will apply the extremely small amount analysis (ICP-MS/MS), which has recently been successful in the fields of analytical chemistry
removal from aqueous solutions; Cost-effectiveness & parametric effectsMaamoun, I.; Eljamal, R.*; Eljamal, O.*
Chemosphere, 312, Part 1, p.137176_1 - 137176_11, 2023/01
Times Cited Count：0 Percentile：0.01(Environmental Sciences)Collaborative Laboratories for Advanced Decommissioning Science; Fukushima University*
JAEA-Review 2022-030, 94 Pages, 2022/12
JAEA-Review-2022-030.pdf:4.87MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of methodology combining chemical analysis technology with informatics technology to understand perspectives property of debris and tie-up style human resource development" conducted in FY2021. The present study aims to Goal of this study is to implement a research plan relate to a development of combinational technology of new chemical analysis with informatics, and the aim is to develop new system for whole image estimation system using small quantities of information. Conducting the collaboration study with JAEA researchers (tie-up style) make connect to the development of human resource from master's course student to post-doctoral researchers who are progress in the local-based and/or many academics
Hamdani, A.; Abe, Satoshi; Ishigaki, Masahiro; Shibamoto, Yasuteru; Yonomoto, Taisuke
Progress in Nuclear Energy, 153, p.104415_1 - 104415_16, 2022/11
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Louie, D. L. Y.*; Aoyagi, Mitsuhiro
SAND2022-14235 (Internet), 29 Pages, 2022/10
This report discusses the progress on the collaboration between Sandia National Laboratories (SNL) and Japan Atomic Energy Agency (JAEA) on the sodium fire research in fiscal year 2022. First, the current sodium pool fire model in MELCOR is discussed. The associated sodium fire input requirements are also presented. The theoretical pool fire model improvement developed at SNL is discussed. A control function model has been developed from this improvement. Then, the validation study of the sodium pool fire model in MELCOR is described. To validate this pool fire model with the enhancement, JAEA F7-1 and F7-2 sodium pool fire experiments are used. The results of the calculation are discussed as well as suggestions for further model improvement. Finally, recommendations are made for new MELCOR simulations for next fiscal year, 2023.
Urushidate, Tadayuki*; Yoda, Tomoyuki; Otani, Shuichi*; Yamaguchi, Toshio*; Kunii, Nobuaki*; Kuriki, Kazuki*; Fujiwara, Kenso; Niizato, Tadafumi; Kitamura, Akihiro; Iijima, Kazuki
JAEA-Review 2022-023, 8 Pages, 2022/09
JAEA-Review-2022-023.pdf:1.19MB
After the accident of the Fukushima Daiichi Nuclear Power Station, the Japan Atomic Energy Agency has newly set up a laboratory in Fukushima and started measuring radioactivity concentrations of environmental samples. In October 2015, Fukushima Radiation Measurement Group has been accredited the ISO/IEC 17025 standard by the Japan Accreditation Board (JAB) as a testing laboratory for radioactivity analysis (
Cs, 
Cs) based on Gamma-ray spectrometry with germanium semiconductor detectors. The laboratory has measured approximately 60,000 of various environmental samples at the end of March 2022. The laboratory quality control and measurement techniques have been accredited by regular surveillance of JAB. In September 2019, the laboratory renewed accreditation as a testing laboratory for radioactivity analysis.
Doi, Daisuke
Proceedings of 29th International Conference on Nuclear Engineering (ICONE 29) (Internet), 7 Pages, 2022/08
Onoda, Yuichi; Uchita, Masato*; Tokizaki, Minako*; Okazaki, Hitoshi*
Proceedings of 29th International Conference on Nuclear Engineering (ICONE 29) (Internet), 6 Pages, 2022/08
The safety analyses were carried out to confirm the sufficiency of the function of the plant protection system against the pump/diagrid link rupture. The target plant is a pool-type SFR of about 600 MWe class equipped with an axially homogeneous core currently under development in Japan. In the pool-type SFR, the primary system piping connects primary pump and the high-pressure sodium plenum located at the inlet of fuel sub-assemblies and called "pump/diagrid link". Because this piping is submerged in the reactor vessel, it is difficult to detect small scale sodium leakage in this piping, and thus a certain large pipe break like guillotine should be assumed and evaluated as a design basis event. In order to confirm the detectability of pump/diagrid link rupture by safety protection system signals, a series of analyses of the guillotine break for a pump/diagrid link were carried out. Sensitivity study had also been performed to consider the uncertainty of the reactivity coefficient in the analyses. The sufficiency of the function of the plant protection system against the pump/diagrid link rupture was confirmed by the analysis results that at least two signals are transmitted for the detection of the event, which is the development target of the plant protection system in pool-type SFR.
Choi, B.; Nishida, Akemi; Shiomi, Tadahiko; Kawata, Manabu; Li, Y.
Transactions of 26th International Conference on Structural Mechanics in Reactor Technology (SMiRT-26) (Internet), 10 Pages, 2022/07
In order to improve the seismic probabilistic risk assessment method, the authors are developing methods related to realistic response, realistic resistance and fragility assessment for buildings and equipment that are important for seismic safety. In this study, in order to identify of building damage mode subjected to large seismic motions, pushover analyses using multiple analysis codes were performed using a 3D FE model of a reactor building. We obtained the analysis results for the identification of local damage mode that contributes to the fragility assessment. In this paper, we report the progress of local damage mode and ultimate strength of the building by the pushover analysis. We also compared this result with the seismic response analysis results.
Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*
JAEA-Review 2022-007, 59 Pages, 2022/06
JAEA-Review-2022-007.pdf:2.09MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2018, this report summarizes the research results of the "Identification of altered phases of fuel debris by laser fluorescence spectroscopy" conducted from FY2018 to FY2021 (this contract was extended to FY2021). Since the final year of this proposal was FY2021, the results for four fiscal years were summarized. The present study aims to identify alteration phases occurring on the surface fuel debris at various conditions, using time-resolved laser fluorescence spectroscopy (TRLFS), which is a selective analytical technique for U(VI), a major constituent of fuel debris and stable in oxidizing conditions. In particular, we pursue to improve its sensitivity and resolution by performing measurements at ultra-low temperature and identify multiple and heterogeneous U(VI)
Hiratsuka, Shinya; Asamori, Koichi; Saiga, Atsushi
JAEA-Research 2022-002, 38 Pages, 2022/06
JAEA-Research-2022-002.pdf:4.49MB
Deep groundwater originates from dehydration of Pacific and Philippine Sea slab subducting beneath Japanese islands, which has characteristics of high temperature and is rich in carbonate species. In this respect, it is very important for geological disposal of high-level radioactive waste to estimate reservoir and migration pathway of deep groundwater. The region where cracks are densely distributed can be regarded as the migration pathway of slab-derived fluid. It is highly probable that the region has strong anisotropy. Shear wave propagating through anisotropic media splits into two mutually orthogonally polarized waves due to shear wave polarization anisotropy. In this report, we applied shear wave splitting analysis to Hongu area of Tanabe City, Wakayama Prefecture and estimated the spatial distribution of leading shear wave polarization direction (LSPD) and arrival time difference between leading and lagging shear waves (dt). Based on comparison with helium isotope ratio of ground water and bubbling gas samples and two-dimensional resistivity structure estimated by previous study, we attempt to estimate migration pathway of slab-derived fluid in Hongu area of Tanabe City, Wakayama Prefecture. The main results are summarized as follows. When helium isotope ratio of groundwater and bubbling gas samples is high, dt value tends to be large. Shear wave propagating through high and low resistivity anomaly zone show small and large dt values, respectively. Previous study suggested that slab-derived fluid migrates from deeper part of western side of Hongu area and wells out in Yunomine and Kawayu hot springs. This is consistent with spatial distribution of dt values estimated by this study.
Louie, D. L. Y.*; Aoyagi, Mitsuhiro
Proceedings of International Topical Meetings on Advances in Thermal Hydraulics (ATH 2022) (Internet), p.316 - 329, 2022/06
-eigenvalue perturbation in Monte Carlo calculationTuya, D.; Nagaya, Yasunobu
Annals of Nuclear Energy, 169, p.108919_1 - 108919_9, 2022/05
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Estimating an effect of a perturbation in a fissile system on its -eigenvalue requires special technique called perturbation theory when the considered perturbation is small. In this study, we develop an adjoint-weighted correlated sampling (AWCS) method based on the exact perturbation theory without any approximation by combining the correlated sampling (CS) method with iterated-fission probability (IFP) based adjoint-weighting method. With the advantages of the CS method being good at providing very small uncertainty for small perturbations and the IFP-based adjoint-weighting method being suitable for continuous-energy Monte Carlo calculation, the developed AWCS method based on the exact perturbation theory offers a new rigorous approach for perturbation calculations. The obtained results by the developed AWCS method for verification problems involving Godiva and simplified STACY density perturbations showed good agreement with the reference calculations.
Ichihara, Yoshitaka*; Nakamura, Naohiro*; Nabeshima, Kunihiko*; Choi, B.; Nishida, Akemi
Kozo Kogaku Rombunshu, B, 68B, p.271 - 283, 2022/04
This paper aims to evaluate the applicability of the equivalent linear analysis method for reinforced concrete, which uses frequency-independent hysteretic damping, to the seismic design of reactor building of the nuclear power plant. To achieve this, we performed three-dimensional FEM analyses of the soil-structure interaction system, focusing on the nonlinear and equivalent linear seismic behavior of a reactor building under an ideal soil condition. From these results, the method of equivalent analysis showed generally good correspondence with the method of the nonlinear analysis, confirming the effectiveness. Moreover, the method tended to lower the structural stiffness compared to the nonlinear analysis model. Therefore, in the evaluation of the maximum shear strain, we consider that the results were more likely to be higher than the results of nonlinear analysis.
Nakano, Keita; Iwamoto, Hiroki; Nishihara, Kenji; Meigo, Shinichiro; Sugawara, Takanori; Iwamoto, Yosuke; Takeshita, Hayato*; Maekawa, Fujio
JAEA-Research 2021-018, 41 Pages, 2022/03
JAEA-Research-2021-018.pdf:2.93MB
Neutronic analysis of beam window of the Accelerator-Driven System (ADS) proposed by Japan Atomic Energy Agency (JAEA) has been conducted using PHITS and DCHAIN-PHITS codes. We investigate gas production of hydrogen and helium isotopes in the beam window, displacement per atom of beam window material, and heat generation in the beam window. In addition, distributions of produced nuclides, heat density, and activity are derived. It was found that at the maximum 12500 appm H production, 1800 appm He production, and damage of 62.1 DPA occurred in the beam window by the ADS operation. On the other hand, the maximum heat generation in the beam window was 374 W/cm
. In the analysis of LBE, 
Bi and 
Po were found to be the dominant nuclides in decay heat and radioactivity. Furthermore, the heat generation in the LBE by the proton beam was maximum around 5 cm downstream of the beam window, which was 945 W/cm.
