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 …

Material balance analysis for wide range of nuclear power generation scenarios

Nishihara, Kenji

JAEA-Data/Code 2020-005, 48 Pages, 2020/07

JAEA-Data-Code-2020-005.pdf:2.95MB
JAEA-Data-Code-2020-005-appendix(CD-ROM).zip:3.62MB

In order to discuss the technological development and human resource development necessary for the future nuclear fuel cycle, various quantitative analyzes were conducted assuming a wide range of future nuclear power generation scenarios. In the evaluation of quantities, the future power generation of LWR and fast reactor, the amount of spent fuel reprocessing, etc. were assumed, and the amount of uranium demand, the accumulation of spent fuel, plutonium, vitrified waste etc. were estimated.

Scenario development on application of engineering technology for geological disposal; Study of influence of earthquake at site construction, operation and closure stages and that impact on safety functions after closure of disposal facility (Contract research)

Takai, Shizuka; Takayama, Hideki*; Takeda, Seiji

JAEA-Data/Code 2016-020, 40 Pages, 2017/03

JAEA-Data-Code-2016-020.pdf:2.42MB

In this report, another group of scenarios for occurrence of earthquake at construction stage, operation stage and closure stage of disposal facility was presented. At first, we compiled information about damage cases of tunnel by earthquake and analyzed conditions for occurrence of damage. Base on this result and the previous report, information of influence of the accidents and human factors on safety functions and information of FEP about THMC variation, we specified events to be considered, which occur by earthquake and influence engineering barriers, natural barriers and long-term safety after closure stage of disposal facility. We compiled influence of the events on safety functions after closure stage of disposal and showed the chains of the influence on long-term safety as scenarios. These results were integrated as a database that could support development of scenarios caused by application of engineering technologies to geological disposal.

Study of treatment scenarios for fuel debris removed from Fukushima Daiichi NPS

Washiya, Tadahiro; Yano, Kimihiko; Kaji, Naoya; Yamada, Seiya*; Kamiya, Masayoshi

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 7 Pages, 2015/05

On March 11, 2011, a severe nuclear accident occurred at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Plant (hereinafter called as F1). After the accident, the Council for the Decommissioning was established, mainly by the government and TEPCO, and a road map for the F1 decommissioning was drawn up. In the road map, the fuel debris removal from the reactors is scheduled to launch around 2020. In this study, the characteristics and technological issues of each potential treatment scenario were extracted, and the scenarios were prioritized in advance of formal evaluations in the future. The preliminary evaluation results show that long term storage and direct disposal have more positive aspects in terms of economic efficiency and radioactive waste generation. On the other hand, stabilizing processing, aqueous processing, and pyrochemical processing have been estimated to have more disadvantages in such aspects.

Analysis of JT-60SA scenarios on the basis of JET and JT-60U discharges

Garcia, J.*; Hayashi, Nobuhiko; Giruzzi, G.*; Schneider, M.*; Joffrin, E.*; Ide, Shunsuke; Sakamoto, Yoshiteru; Suzuki, Takahiro; Urano, Hajime; JT-60 Team; et al.

Europhysics Conference Abstracts (Internet), 38F, p.P1.029_1 - P1.029_4, 2014/06

http://ocs.ciemat.es/EPS2014PAP/pdf/P1.029.pdf

Remote handling design for moderator-reflector maintenance in JSNS

Teshigawara, Makoto; Aizawa, Hideyuki; Harada, Masahide; Kinoshita, Hidetaka; Meigo, Shinichiro; Maekawa, Fujio; Kaminaga, Masanori; Kato, Takashi; Ikeda, Yujiro

JAERI-Tech 2005-029, 24 Pages, 2005/05

JAERI-Tech-2005-029.pdf:3.38MB

This report introduces the present design status of remote-handling devices for activated and used components such as moderator and reflector in a spallation neutron source of the Material and Life Science Facility (MLF) at J-PARC. The design concept and maintenance scenario are also mentioned. A key maintenance scenario adopts that the used components should be taken out from the MLF to the other storage facility after the volume reduction of them. Almost full remote handling is available to the maintenance work except for the connection/disconnection pipes of the cooling water. Total six remote handling devices are used for moderator-reflector maintenance. They are also available to the proton beam window and muon target maintenance. Maintenance scenario is separated into two works. One is to replace used components to new ones during beam-stop and the other is dispose used components during beam operation. Required period of replacement work is estimated to be 15 days, on the other hand, the disposal work is 26 days after dry up work (30 days), respectively.

Long-term perspective of nuclear energy supply using uranium extracted from seawater

Uotani, Masaki*; Shimizu, Takao*; Tamada, Masao

Proceedings of 2003 International Congress on Advances in Nuclear Power Plants (ICAPP '03) (DVD-ROM), 8 Pages, 2003/00

The present paper describes the current technology of uranium recovery from seawater by using radiation-induced graft-adsorbent and the utilization scenario of collected uranium from the viewpoint of long-term perspective of nuclear energy demand in Japan. The several thousand tons of uranium will be required in the latter half of 21st century in Japan, even if the plutonium is practically used in fast breeder reactors (FBRs). This demand of uranium can be supplied by the uranium recovered from seawater if the recovery cost is reasonable. In conclusion, the utilization of uranium from seawater will be able to play an essential role of providing enough time to develop safe and economical FBRs.

Transmutation of I using an accelerator-driven system

Nishihara, Kenji; Takano, Hideki

Nuclear Technology, 137(1), p.47 - 59, 2002/01

https://doi.org/10.13182/NT02-A3256

no abstracts in English

Mass balance of MA accumulation and transmutation in double strata transmutation system

Nishihara, Kenji; Ando, Yoshihira*; Takano, Hideki

JAERI-Research 99-074, p.24 - 0, 2000/01

JAERI-Research-99-074.pdf:1.05MB

no abstracts in English

Safety scenario and integrated thermofluid test

Seki, Yasushi; Kurihara, Ryoichi; Nishio, Satoshi; Ueda, Shuzo; Aoki, Isao; Ajima, Toshio*; Kunugi, Tomoaki; Takase, Kazuyuki; Shibata, Mitsuhiko

Fusion Engineering and Design, 42(1-4), p.37 - 44, 1998/09

https://doi.org/10.1016/S0920-3796(98)00123-9

no abstracts in English