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); FY2023 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Fukushima University*

JAEA-Review 2025-002, 108 Pages, 2025/07

JAEA-Review-2025-002.pdf:5.25MB

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 FY2023. 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 from FY2019 to FY2023. 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 fields research. We are in progress to grow international-minded human resources.

Human resource development related to remote control technology for monitoring inside RPV pedestal during retrieval of fuel debris (Contract research); FY2023 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*

JAEA-Review 2025-001, 94 Pages, 2025/06

JAEA-Review-2025-001.pdf:6.21MB

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 FY2023. 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 "Human resource development related to remote control technology for monitoring inside RPV pedestal during retrieval of fuel debris" conducted from FY2019 to FY2023. The present study aims to construct a monitoring platform for understanding the status inside a reactor during fuel debris removal, and measurement and visualization by sensors moving on the platform. In addition, to develop research personnel through research education by participating in such research projects, classroom lectures, and facility tours is also a goal of this project. In FY2023, along with the verification of each system, a three-dimensional reconstruction model was generated using images acquired from a moving camera on the monitoring platform in a simulated environment, and an integrated experiment was conducted to demonstrate that it is possible to present images from the optimal viewpoint for the visualization target, with the cooperation of each research theme.

Methods for regulating depth of corrosion fissures in simulated fastener holes of 7050-T7451 aluminum alloy

Aoyama, Takahito; Choudhary, S.*; Pandaleon, A.*; Burns, J. T.*; Kokaly, M.*; Restis, J.*; Ross, J.*; Kelly, R. G.*

Corrosion, 81(6), p.609 - 621, 2025/06

https://doi.org/10.5006/4739

Incommensurate antiferromagnetism in UTe under pressure

Knafo, W.*; Thebault, T.*; Raymond, S.*; Manuel, P.*; Khalyavin, D. D.*; Orlandi, F.*; Ressouche, E.*; Beauvois, K.*; Lapertot, G.*; Kaneko, Koji; et al.

Physical Review X, 15(2), p.021075_1 - 021075_16, 2025/05

https://doi.org/10.1103/PhysRevX.15.021075

Density, surface tension, and viscosity of molten Ni-based superalloys using the maximum bubble pressure and oscillating crucible methods

Nishi, Tsuyoshi*; Matsumoto, Saori*; Yamano, Hidemasa; Hayashi, Kiichiro*; Endo, Rie*; Bell, M. R.*; Neubert, L.*; Volkova, O.*

Steel Research International, 96(5), p.2300766_1 - 2300766_6, 2025/05

https://doi.org/10.1002/srin.202300766

The density of Ni-based superalloys is measured using the maximum bubble pressure (MBP) method. The viscosity is evaluated using the oscillating crucible method. The surface tension is simultaneously measured using the MBP method.

Incorporation of boron into metakaolin-based geopolymers for radionuclide immobilisation and neutron capture potential

Niu, X.*; Elakneswaran, Y.*; Li, A.*; Seralathan, S.*; Kikuchi, Ryosuke*; Hiraki, Yoshihisa; Sato, Junya; Osugi, Takeshi; Walkley, B.*

Cement and Concrete Research, 190, p.107814_1 - 107814_17, 2025/04

https://doi.org/10.1016/j.cemconres.2025.107814

Annual report for FY2023 on the activities of radiation safety in Nuclear Science Research Institute etc. (April 1, 2023 - March 31, 2024)

Department of Radiation Protection, Nuclear Science Research Institute; Nuclear Facilities Management Section, Aomori Research and Development Center

JAEA-Review 2024-056, 113 Pages, 2025/03

JAEA-Review-2024-056.pdf:3.1MB

This annual report describes the activities in the 2023 fiscal year of Department of Radiation Protection in Nuclear Science Research Institute, Sector of Nuclear Science Research, Harima Synchrotron Radiation Radioisotope Laboratory and Nuclear Facilities Management Section in Aomori Research and Development Center, Sector of Nuclear Fuel, Decommissioning and Waste Management Technology Development. The activities described in this reports are environmental monitoring, radiation protection practices in workplaces, individual monitoring, maintenance of monitoring instruments, and research and development of radiation protection. At these institutes the occupational exposures did not exceed the dose limits. The radioactive gaseous and liquid discharges from the facilities were well below the prescribed limits. The research and development activities produced certain results in the fields of radiation protection technique.

Assessment report of research and development activities in FY2023; Activity "Implementation and technological development of decommissioning of nuclear facilities" and "Implementation and technological development of radioactive waste processing" (In-advance evaluation)

Nuclear Backend Technology Development

JAEA-Evaluation 2024-002, 86 Pages, 2025/03

JAEA-Evaluation-2024-002.pdf:8.29MB

Japan Atomic Energy Agency (hereinafter referred to as "JAEA") consulted the "Evaluation Committee on Research and Development Activities for Decommissioning" (hereinafter referred to as "Committee") about the in-advance evaluation of research themes which had started after FY2021 of R&D plan for the 4th medium- and long-term objectives period concerning "Decommissioning of nuclear facilities and development of technologies for the treatment of related radioactive waste" project in accordance with the "Guideline for evaluation of government R&D activities". In response, the Committee evaluated to the evaluation points of view made by JAEA.

Evaluation of uranium-233 neutron capture cross section in keV region

Otsuka, Naohiko*; Tada, Kenichi; Cabellos, O.*; Iwamoto, Osamu

Annals of Nuclear Energy, 212, p.110977_1 - 110977_9, 2025/03

https://doi.org/10.1016/j.anucene.2024.110977

The uranium-233 neutron capture cross section between 3 keV and 1 MeV was evaluated considering the recent new alpha-value measurement performed at the Los Alamos National Laboratory LANCE facility. The obtained capture cross section is systematically lower than the capture cross section in the JENDL-5 library and the reduction is close to 50% around 20 keV. The newly evaluated cross section was validated against 166 criticality experiments chosen from the ICSBEP handbook by performing Monte Carlo neutron transport calculation with the JENDL-5 library, and slight reduction of the chi-square value was achieved by adoption of the newly evaluated capture cross section.

Magnetite stoichiometry (Fe(II)/Fe(III)) controls on trivalent chromium surface speciation

Scaria, J.*; Pdrot, M.*; Fablet, L.*; Yomogida, Takumi; Nguyen, T. T.*; Sivry, Y.*; Catrouillet, C.*; Pradas del Real, A. E.*; Choueikani, F.*; Vantelon, D.*; et al.

Environmental Science & Technology, 59(11), p.5747 - 5755, 2025/03

https://doi.org/10.1021/acs.est.4c12899

Understanding and predicting the interaction mechanisms between chromium and magnetite is of particular interest to elucidate the biogeochemical behavior of Cr in the environment and to develop optimal soil remediation and water treatment strategies. However, while the elimination of the most toxic form of (Cr(VI)) by its reduction to Cr(III) has widely been documented, elucidating the exact mechanism involved in Cr(III) sorption to magnetite has attracted less attention. This study examined the interaction of Cr(III) solution with 10 nm-sized magnetites, whose stoichiometries were carefully defined and preserved in anaerobic conditions. This study reveals the joint effects of pH and magnetite stoichiometry on Cr(III) sorption mechanism, and that Cr(III)-(hydr)oxide precipitation is not necessarily the driving process of Cr(III) elimination from solutions. These results will help predict the fate and transport of chromium, as well as developing magnetite-based chromium remediation processes.