Study of corrosion and degradation of the objects in the nuclear reactor by microorganisms (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Keio University*

JAEA-Review 2021-048, 181 Pages, 2022/01

JAEA-Review-2021-048.pdf:14.5MB

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 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 (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 "Study of corrosion and degradation of the objects in the nuclear reactor by microorganisms" conducted in FY2019 and FY2020. Since the final year of this proposal was FY2020, the results for two fiscal years were summarized. The purpose of the study is to obtain knowledge related to microorganisms that will be useful in the decommissioning process of 1F. Therefore, we clarified the current conditions of the microbial community inhabiting the power plant and its premises. Environmental samples were taken from several sites such as, topsoil from the south of the plant site boundary (south of the treated water tanks), seabed soil and its above water near the plant, surface water 3km offshore …

Superconducting magnet system in a fusion reactor

Okuno, Kiyoshi; Shikov, A.*; Koizumi, Norikiyo

Journal of Nuclear Materials, 329-333(Part1), p.141 - 147, 2004/08

https://doi.org/10.1016/j.jnucmat.2004.04.151

A tokamak fusion reactor requires a superconducting magnet system for plasma confinement and control. Higher magnetic field of the toroidal field (TF) coil can offer better performance of the reactor. Therefore, fusion magnet development always drives a new superconductor to be used in a large magnet on an industrial basis. Magnets for the International Thermonuclear Experimental Reactor (ITER) use NbSn in order to generate a peak magnetic field of 13 T. Technologies for NbSn superconductor has made a significant progress through the extensive development in ITER including the manufacture of the full-scale model coils. A next generation superconductor, NbAl, has outstanding features of large critical current density at the high field. High Tc (Critical Temperature) superconductor (HTS) is another candidate, and if it becomes available, a magnetic filed above 20 T can be realized in fusion reactor. However, technical issues have to be solved for the application of these innovate superconducting materials in Fusion Reactor.

Investigation on marine radioactivity in radioactive waste dumping areas in the northwest pacific ocean and its marginal seas; JAERI's activities in the 2nd Japanese-Korean-Russian joint expedition 1995

Togawa, Orihiko; ; Mizushima, Toshihiko; Yabuuchi, Noriaki; Kobayashi, Takuya

JAERI-Research 98-062, 50 Pages, 1998/10

JAERI-Research-98-062.pdf:3.49MB

no abstracts in English

Importance determination method for geometry splitting with Russian roulette in Monte Carlo calculations of thick and complicated core shielding structure

Murata, Isao; Shindo, Ryuichi; Shiozawa, Shusaku

Journal of Nuclear Science and Technology, 32(10), p.971 - 980, 1995/10

https://doi.org/10.3327/jnst.32.971

no abstracts in English