Application of the spectral determination method to unified -, - and X-ray spectra

Oshima, Masumi*; Goto, Jun*; Hayakawa, Takehito*; Asai, Masato; Shinohara, Hirofumi*; Suzuki, Katsuyuki*; Shen, H.*

Journal of Nuclear Science and Technology, 10 Pages, 2025/00

https://doi.org/10.1080/00223131.2024.2439921

The spectrum determination method (SDM) is the method to determine radioactivities by analyzing full spectral shape of - or rays through least-squares fitting by referring to standard - and spectra. In this paper, we have newly applied the SDM to a unified spectrum composed of two spectra measured with a Ge detector and a liquid scintillation counter. By analyzing the unified spectrum, uncertainties of deduced radioactivities have been improved. We applied this method to the unified spectrum including 40 radionuclides with equal intensities, and have deduced their radioactivities correctly.

Development and evaluation of a real-time 3D positioning embedded system combining wireless UWB and camera image analysis (Contract research); FY2022 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Tokai National Higher Education and Research System*

JAEA-Review 2024-027, 77 Pages, 2024/11

JAEA-Review-2024-027.pdf:6.0MB

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 FY2022. 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 FY2022, this report summarizes the research results of the "Development and evaluation of a real-time 3D positioning embedded system combining wireless UWB and camera image analysis" conducted in FY2022. The present study aims to realize an embedded system that combines two of the latest popular technologies, "wireless UWB (Ultra Width Band)" and "multi-camera object recognition," with the goal of simple realtime 3D positioning with less than 10 cm accuracy by a human or robot for measuring air doses in nuclear reactor buildings.

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 (Contract Research); FY2022 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; University of Fukui*

JAEA-Review 2024-014, 112 Pages, 2024/08

JAEA-Review-2024-014.pdf:8.22MB

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 FY2022. 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 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 FY2022. The present study aims to clarify the debris formation mechanism and utilize the results to refine the accident scenario. In the backward analysis of oxide debris formation, we succeeded in the formation of simulated fuel particle by the aerodynamic levitation method and ejection of melted oxides from tungsten pipe with a small hole. And we demonstrated the formation of simulated fuel debris of U1-No.15 obtained by the sampling in 1F.

Fuel debris criticality analysis technology using non-contact measurement method (Contract research); FY2022 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*

JAEA-Review 2024-013, 48 Pages, 2024/07

JAEA-Review-2024-013.pdf:1.99MB

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 FY2022. 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 FY2022. 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, National Institute of Advanced Industrial Science and Technology, and Nagaoka University of Technology as the second year of three years research project.

Resilient design in nuclear energy; Critical lessons from a cross-disciplinary analysis of the Fukushima Dai-ichi Nuclear accident

Ayoub, A.*; Wainwright, Haruko*; Sansavini, G.*; Gauntt, R.*; Saito, Kimiaki

iScience (Internet), 27(4), p.109485_1 - 109485_15, 2024/04

https://doi.org/10.1016/j.isci.2024.109485

Development of methodology combining chemical analysis technology with informatics technology to understand perspectives property of debris and tie-up style human resource development (Contract research); FY2022 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Fukushima University*

JAEA-Review 2023-024, 109 Pages, 2024/03

JAEA-Review-2023-024.pdf:5.42MB

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 FY2022. 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 FY2022. 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.

Accident consequence analysis for JMTR as a decommission facilities

Nagata, Hiroshi; Omori, Takazumi; Maeda, Eita; Otsuka, Kaoru; Nakano, Hiroko; Hanakawa, Hiroki; Ide, Hiroshi

JAEA-Review 2023-033, 40 Pages, 2024/01

JAEA-Review-2023-033.pdf:1.39MB

Japan Materials Testing Reactor (JMTR) was decided as a one of decommission facilities in April 2017. In order to submit the decommissioning plan to the Nuclear Regulation Authority, the type of accident assumed in the first stage of the decommissioning plan was selected, and the public exposure dose was evaluated. A fuel handling accident and a fire accident during storage of waste were selected as assumed accidents in the first stage of the decommissioning plan. An evaluation of the public exposure dose from the radioactive materials released into the atmosphere due to these accidents was estimated to be a maximum of 0.019 mSv (due to a fire accident during storage of waste). This estimated value was found to be sufficiently smaller than the judging criteria (5 mSv), and not to pose a significant risk of radiation exposure to the general public.

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 (Contract Research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

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.

Study on rational treatment/disposal of contaminated concrete waste considering leaching alteration (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

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 …

Development of methodology combining chemical analysis technology with informatics technology to understand perspectives property of debris and tie-up style human resource development (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

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 …