Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*
JAEA-Review 2024-022, 59 Pages, 2024/09
JAEA-Review-2024-022.pdf:4.27MB
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 "Investigation of effects of nano interfacial phenomena on dissolution aggregation of alpha nanoparticles by using micro nano technologies" conducted in FY2022. To ensure the safety of retrieval and storage management of nuclear fuel debris generated by the Fukushima Daiichi Nuclear Power Station accident, understanding of dissolution-denaturation behavior of the fuel debris alpha particles is one of the most crucial issues. This research aims to create novel microfluidic real-time measurement device for elucidating dissolution, aggregation, and denaturation processes of metal oxide nanoparticles under various solution environments, and clarify their nano-size and interfacial effects.
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*
JAEA-Review 2024-010, 112 Pages, 2024/08
JAEA-Review-2024-010.pdf:6.49MB
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 "Uncertainty reduction of the FPs transport mechanism and debris degradation behavior and evaluation of the reactor contamination of debris state on the basis of the accident progression scenario of Fukushima Daiichi Nuclear Power Station Unit 2 and 3" conducted in FY2022. The present study aims to elucidate the cause of the high dosage under shield plug by clarification of to the cesium behavior of migration, adhesion to structure and deposition as well as evaluate the properties of metal-rich debris predeceasing melted through the materials science approach based on the most probable scenario of accident progression of Unit 2 and 3. In this fiscal year, the followings were achieved.
Journeau, C.*; Molina, D.*; Brackx, E.*; Berlemont, R.*; Tsubota, Yoichi
Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR2022) (Internet), 5 Pages, 2022/10
CEA has manufactured a series of Fukushima Daiichi fuel debris simulants, either with depleted uranium oxide or with hafnium oxide as a surrogate of UO
. In ex-vessel compositions resulting from an interaction between corium and concrete, the oxidic phase density becomes lighter than that of the metallic phase, which segregates at the bottom. Three of these metallic phases have been mechanically cut at CEA Cadarache with handsaw and with core boring tool in FUJISAN facility. It appeared that two of these metallic blocks were extremely hard to cut (one from a fabrication with uranium oxide, the other from a simulant block) while the last one was more easily cut. The similarities and differences in metallographic analyses (SEM-EDS and XRD) of these three metal blocks will be presented and discussed. This experience provides useful learnings in view of the cutting and retrieval of fuel debris from Fukushima Daiichi.
Ohgama, Kazuya; Ota, Hirokazu*; Oki, Shigeo; Iizuka, Masatoshi*
Proceedings of 2019 International Congress on Advances in Nuclear Power Plants (ICAPP 2019) (Internet), 9 Pages, 2019/05
Ohgama, Kazuya; Aliberti, G.*; Stauff, N. E.*; Oki, Shigeo; Kim, T. K.*
Mechanical Engineering Journal (Internet), 4(3), p.16-00592_1 - 16-00592_9, 2017/06
Ohgama, Kazuya; Ota, Hirokazu*; Ikusawa, Yoshihisa; Oki, Shigeo; Ogata, Takanari*
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 6 Pages, 2017/04
Stauff, N. E.*; Ohgama, Kazuya; Aliberti, G.*; Oki, Shigeo; Kim, T. K.*
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 10 Pages, 2017/04
Ohgama, Kazuya; Aliberti, G.*; Stauff, N. E.*; Oki, Shigeo; Kim, T. K.*
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 8 Pages, 2017/04
Ohgama, Kazuya; Aliberti, G.*; Stauff, N. E.*; Oki, Shigeo; Kim, T. K.*
Proceedings of 24th International Conference on Nuclear Engineering (ICONE-24) (DVD-ROM), 6 Pages, 2016/06
Under the cooperative effort of the Civil Nuclear Energy R&D Working Group within the framework of the U.S.-Japan bilateral, Argonne National Laboratory (ANL) and Japan Atomic Energy Agency (JAEA) have been performing benchmark study using Japan Sodium-cooled Fast Reactor (JSFR) design with metal fuel. In this benchmark study, core characteristic parameters at the beginning of cycle were evaluated by the best estimate deterministic and stochastic methodologies of ANL and JAEA. The results obtained by both institutions are agreed well with less than 200 pcm of discrepancy on the neutron multiplication factor, and less than 3% of discrepancy on the sodium void reactivity, Doppler reactivity, and control rod worth. The results by the stochastic and deterministic were compared in each party to investigate impacts of the deterministic approximation and to understand potential variations in the results due to different calculation methodologies employed. Impacts of the nuclear data libraries were also investigated using a sensitivity analysis methodology.
Kato, Tetsuya*; Iizuka, Masatoshi*; Inoue, Tadashi*; Iwai, Takashi; Arai, Yasuo
Journal of Nuclear Materials, 340(2-3), p.259 - 265, 2005/04
Times Cited Count：24 Percentile：81.59(Materials Science, Multidisciplinary)no abstracts in English
Shelley, A.; Kugo, Teruhiko; Shimada, Shoichiro*; Okubo, Tsutomu; Iwamura, Takamichi
JAERI-Research 2004-002, 47 Pages, 2004/03
JAERI-Research-2004-002.pdf:3.08MB
Neutronic study has been done for a PWR-type reduced-moderation water reactor with seed-blanket fuel assemblies to achieve a high conversion ratio, a negative void coefficient and a high burnup by using a MOX fuel. The results of the precise assembly burnup calculations show that the recommended numbers of seed and blanket layers are 15(S15) and 5(B5), respectively. By the optimization of axial configuration, the S15B5 assembly with the seed of 1000
2 mm high, internal blanket of 150 mm high and axial blanket of 4002 mm high is recommended. In this configuration, the conversion ratio is 1.0 and the core average burnup is 38 GWd/t. The S15B5 assembly can attain the core average burnup of 45 GWd/t by decreasing the height of seed to 5002 mm, however, the conversion ratio becomes 0.97. The void and fuel temperature coefficients are negative for both of the configurations. Effect of metal or T-MOX (PuO+ThO) fuel has been also investigated. Metal improves the conversion ratio but makes the void coefficient worse. T-MOX improves the void coefficient, but decreases the conversion ratio.
Kato, Chiaki
JAERI-Research 2003-013, 143 Pages, 2003/08
JAERI-Research-2003-013.pdf:22.12MB
This study is investigation about stress corrosion cracking (SCC) of zirconium in nuclear fuel reprocessing. Chapter 1 is described background. Chapter 2 is explained experimental apparates. Chapter 3 is described the increased oxidization potential on the heat-transfer surface and suggested the initiation of SCC on a boiling heat-transfer surface. Chapter 4 is described that the SCC susceptibility increased with increasing nitric acid concentration and solution temperature on notched specimen by SSRT. In addition, the SCC susceptibility effected by the crystal anisotropy by the hot rolling direction and increased on a parallel face to the rolling direction. Chapter 5 is described that the SCC susceptibility increased in HAZ/base metal boundary in order to the preferential orientation of cleavage plane (0002). Chapter 6 is described that the increased oxidization potential on the heat-transfer surface is attributed to the reduction of nitrous acid concentration by the thermal decomposition on the surface and the removal of the decomposition product from solution by boiling bubbles.
Verfondern, K.*; Sumita, Junya; Ueta, Shohei; Sawa, Kazuhiro
JAERI-Research 2000-067, 127 Pages, 2001/03
JAERI-Research-2000-067.pdf:6.64MB
no abstracts in English
Ogawa, Toru; ; Ito, Akinori; ; Sekino, Hajime; Nishi, Masahiro; Ishikawa, Akiyoshi; Akabori, Mitsuo
Journal of Alloys and Compounds, 271-273, p.670 - 675, 1998/00
Times Cited Count：8 Percentile：52.29(Chemistry, Physical)no abstracts in English
; Akabori, Mitsuo; Ogawa, Toru
JAERI-Tech 96-052, 18 Pages, 1996/11
no abstracts in English
Oigawa, Hiroyuki; Iijima, Susumu
JAERI-Research 95-007, 93 Pages, 1995/02
JAERI-Research-95-007.pdf:2.7MB
no abstracts in English
Sawa, Kazuhiro; Shiozawa, Shusaku; Fukuda, Kosaku;
Journal of Nuclear Science and Technology, 29(9), p.842 - 850, 1992/09
no abstracts in English
Ogawa, Toru; Iwai, Takashi;
J. Less-Common Met., 175, p.59 - 69, 1991/00
no abstracts in English
Takada, Hiroshi; Kanno, Ikuo; Takizuka, Takakazu; Akabori, Mitsuo; ; Kaneko, Yoshihiko
JAERI-M 90-131, 18 Pages, 1990/08
no abstracts in English
; ; ; Ogawa, Toru; ; ; ; Saito, Hioraki*
Nuclear Technology, 89, p.183 - 193, 1990/02
Times Cited Count：29 Percentile：90.96(Nuclear Science & Technology)no abstracts in English
