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Togawa, Orihiko; Hokama, Tomonori; Hiraoka, Hirokazu; Saito, Shota
JAEA-Research 2023-011, 78 Pages, 2024/03
When radionuclides are released into the atmospheric environment at a nuclear emergency, protective measures such as evacuation and temporal relocation are carried out using motor vehicles such as private cars and buses to reduce radiation exposure to residents. To confirm conditions of contamination for the evacuated/relocated residents and the used motor vehicles, contamination inspection is conducted in the middle of the route from border areas of Nuclear Emergency Planning Zone to evacuation shelters. In the present inspection in Japan, a value of OIL4 = 40,000 cpm is used as decontamination criteria. For the details and derivation methods of the value, however, no official documents are found which give systematically detailed descriptions and explanation. It is also recognized that even few experts on nuclear emergencies can explain these subjects in detail as a whole. In order to explain scientifically and technically the OIL4 value of decontamination criteria used in contamination inspection in Japan, this report aims at investigating and estimating the deviation methods of OIL4, and examining and considering these results. To achieve the objectives, we show the bases for decontamination criteria, and investigate and estimate the derivation methods for limits of a surface contamination density corresponding to the generic criteria for each exposure pathway. Moreover, we give the OIL4 value some consideration and suggestions from a viewpoint of positioning and feature of OIL4 in Japan, and cautionary points at revising the value.
Hashimoto, Makoto
Nihon Genshiryoku Gakkai-Shi ATOMO, 61(7), p.525 - 528, 2019/07
no abstracts in English
Kameo, Yutaka; Nakashima, Mikio; Hirabayashi, Takakuni*
Journal of Nuclear Science and Technology, 41(9), p.919 - 924, 2004/09
Times Cited Count:13 Percentile:61.44(Nuclear Science & Technology)A new laser decontamination method utilizing a gel made from a sodium silicate solution and an acid was developed for removing radioactive nuclide incorporated into a surface oxide layer on metal waste. Decontamination tests were carried out using both simulated contaminated samples and pipe specimens cut from the primary coolant system of the Japan Power Demonstration Reactor. In the case of surface oxide layer consisting mainly of iron oxide, more than 99% of surface radioactivities were removed after two to three decontamination runs. In order to ascertain the role of laser irradiation on chemical reactions, chemical states of O and Fe in the oxide layer before and after decontamination were analyzed by X-ray photoelectron spectroscopy. It was found that the oxide layer was dissolved into the acid-containing gel, and the reaction was extensively promoted by the laser irradiation.
Tachibana, Mitsuo; Ito, Hirokuni*; Hatakeyama, Mutsuo*; Yanagihara, Satoshi
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(1), p.120 - 127, 2004/03
The RAPID-1600 was developed to measure a low-level radioactive contamination on building surfaces automatically. The double layered detectors are structured by two gas flow type detectors with a rays shielding plate between the two detectors and it is horizontally positioned. The lower counter measures and rays and the upper counter measures rays. The rays counting rates are derived by subtracting rays counting rates of the upper counter from and rays counting rates of the lower counter. This mechanism results in sensitive to rays against to low background radiation conditions. The driving unit can move omnidirectionally by controlling two driving wheels individually, and has a capability to correct its position if an orbital error is detected by the self-position identification system. The RAPID-1600 was successfully applied to the actual measurement in the radioisotope production facilities. The RAPID-1600 is expected to be a useful tool for measurement of radioactivity in decommissioning nuclear facilities.
Kinouchi, Nobuyuki; Oishi, Tetsuya; Yoshida, Makoto
Radioisotopes, 50(5), p.183 - 189, 2001/05
no abstracts in English
Endo, Akira; Oishi, Tetsuya; Takahashi, Fumiaki; Murakami, Hiroyuki
JAERI-Conf 97-008, 184 Pages, 1997/06
no abstracts in English
Kaneko, Kiichi; Masaki, Kei;
Bunshi Kagaku Kenkyujo Gijutsu Kenkyukai Hokokushu, 0(15), p.108 - 111, 1996/07
no abstracts in English
Hoken Butsuri, 29, p.460 - 462, 1994/00
no abstracts in English
Sato, Nobuyuki; ; Kobayashi, Makoto; Nakazawa, Takashi; ; ; Ikezawa, Yoshio
Proc. of the Int. Conf. on Radiation Effects and Protection, p.440 - 445, 1992/00
no abstracts in English
; ; Onodera, Junichi; ; Ikezawa, Yoshio
Proc. of the Int. Conf. on Radiation Effects and Protection, p.434 - 439, 1992/00
no abstracts in English
Ikezawa, Yoshio
Nihon Genshiryoku Gakkai-Shi, 33(5), p.439 - 440, 1991/05
no abstracts in English
Matsui, Hiroshi; Ikezawa, Yoshio
Firumu Bajji Nyusu, 0(161), p.7 - 10, 1990/05
no abstracts in English
; Ikezawa, Yoshio
Hoken Butsuri, 25(3), p.294 - 298, 1990/00
no abstracts in English
;
Genshiryoku Kogyo, 32(9), p.70 - 74, 1986/09
no abstracts in English
Wadachi, Yoshiki
Radioisotopes, 23(12), p.723 - 728, 1974/12
no abstracts in English
; ; ; ;
Hoken Butsuri, 8(2), p.67 - 71, 1973/02
no abstracts in English