Dose estimation for contaminated soil storage in living environment

Takai, Shizuka; Shimada, Asako; Sawaguchi, Takuma; Takeda, Seiji; Kimura, Hideo

Radiation Protection Dosimetry, 188(1), p.1 - 7, 2020/01

https://doi.org/10.1093/rpd/ncz250

After the Fukushima Nuclear Power Plant accident, most of radiocesium-contaminated soil generated from decontamination activities outside Fukushima prefecture has been stored at decontamination sites such as schools, parks and residential lands (storage at sites) according to the Decontamination Guidelines. However, additional exposure due to the present storage has not been evaluated. Moreover, entering storage sites, which is not restricted for storage at sites, was not considered in safety assessment conducted in the guidelines. To continue the storage and confirm the effectiveness, understanding of present possible exposures is important. In this study, we evaluated exposure doses for residents and users of storage sites based on the present situation. As a result, annual doses due to residence were 10 to 10 mSv y and doses due to annual entries were of the order of 10 mSv y. Hence, we confirmed that the exposure due to present storage outside Fukushima is significantly less than 1 mSv y.

Technical/institutional prerequisite for nuclear forensics response framework

Tamai, Hiroshi; Okubo, Ayako; Kimura, Yoshiki; Kokaji, Lisa; Shinohara, Nobuo; Tomikawa, Hirofumi

Dai-37-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu (CD-ROM), 8 Pages, 2017/02

Nuclear Forensics capability has been developed under the international collaborations. For its effective function, technical development in analysis of seized nuclear materials as well as the institutional development in comprehensive response framework are required under individual national responsibility. In order to keep the "chain of custody" in the proper operation of sample collection at the event scene, radiological analysis at the laboratory, storage of the samples, and further inspection and trial, close cooperation and information sharing between relevant organisations are essential. IAEA issues the Implementing Guide to provide the model action plan and assists individual national development. International cooperation for the technical improvement and awareness cultivation is promoted. Examples in such national developments will be introduced and prospective technical/institutional prerequisite for nuclear forensics response framework will be studied.

A Long-term maintenance plan for the JT-60 power supply

Omori, Yoshikazu; Matsukawa, Makoto; Omori, Shunzo; Terakado, Tsunehisa; Okano, Jun; Noda, Masaaki*

NIFS-MEMO-36, p.358 - 361, 2002/06

no abstracts in English

Design study of handling and storage system of spent target for neutron scattering facility

Adachi, Junichi*; Sasaki, Shinobu; Kaminaga, Masanori; Hino, Ryutaro

FAPIG, (155), p.48 - 54, 2000/07

no abstracts in English

Physico-chemical studies on the disposal of miscellaneous radioactive waste through A single-step process (III)

Iwase, Masanori*

JNC TJ8400 2000-063, 78 Pages, 2000/03

JNC-TJ8400-2000-063.pdf:1.93MB

This study is aimed at controlling oxidation reaction of molten metal by ash in incineration systems, and at positively utilizing the oxidation reaction for decontamination of slag. In this year, in order to investigate physico-chemical properties of mixed fused salt containing alkali sulfates, with special focus on the behaviour of oxygen anion in the melts, Cu / Cu redox equilibrium experiments were carried out. Among the effect of various parameters on Cu / Cu ratio in binary and ternary alkali sulfate melts, the effect of partial pressures of oxygen and SO was mainly investigated in the study. Variation in Cu / Cu ratio were presented as the function of partial pressures of oxygen and SO, respectively. Possible thermodynamic interpretation were made on the experimental results. In addition, the dissolution of CrO in mixed alkali sulfates were also investigated as a first step to elucidate the mechanism of hot corrosion. With this investigation, an important finding was obtained that the solubility of CrO for melts with same average ionic radius, in other words, oxygen ion activity, were essentially identical under constant temperature and atmosphere.

Decommissioning of the JRR-2

Kaieda, Keisuke; ; Arigane, Kenji

Genshiryoku Nenkan '98/'99-Nen Ban, P. 216, 1998/12

no abstracts in English

None

; ; ; ; ; ;

PNC TN8440 98-025, 111 Pages, 1998/07

PNC-TN8440-98-025.pdf:11.06MB

None

Decommissioning of the nuclear ship Mutsu

Nihon Bunseki Senta Koho, 0(28), p.2 - 15, 1996/01

no abstracts in English

None

Okada, Toshio; *; *; *; *; Miyake, Osamu; Sasaki, Shuichi

PNC TN1410 94-006, 57 Pages, 1994/11

PNC-TN1410-94-006.pdf:10.29MB

no abstracts in English

High radioactive - solid Waste treatment facilities Conceptual design study

*; Seki, Sadao*; *

PNC TJ9409 91-001, 164 Pages, 1991/02

PNC-TJ9409-91-001.pdf:4.41MB

This report describes the result of conceptual design study concerned with "High Radioactive - Solid Waste Treatment Facilities, "which will be planed for the purpose of volume reduction and stabilization of High Radioactive - solid wastes generated and stocked in the O-arai Engineering Center of PNC. In this conceptual design study the basic process of the facilities, which are sufficient to treat each waste and develop technologies, are clarified. This report consist with: (1)Clarification of waste to be treated. (2)Study on the treatment technology and process. (3)Conceptual design of facilities and equipment. (4)Estimation of construction cost and schedule.