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Takahashi, Tomoyuki
KURRI-KR-18, p.213 - 220, 1997/00
no abstracts in English
Watanabe, Miki*; Amano, Hikaru; Onuma, Yoshikazu*; Ueno, Takashi; Matsunaga, Takeshi; Yanase, Nobuyuki
Proc. of 4th Int. Conf. on Nucl. and Radiochemistry, 2, 4 Pages, 1996/00
no abstracts in English
Shimada, Taro; Nabekura, Nobuhide*; Miwa, Kazuji; Takeda, Seiji
no journal, ,
It is required to confirm that dose of public using the land after site release for is less than the criteria by dose evaluation based on the contamination distribution obtained by site survey before the completion of the decommissioning of nuclear facilities. Therefore JAEA is developing the methodology to evaluate public dose. We studied estimating methods for contamination distribution based on the data from the scoping survey and the final sampling measurement with errors using external drift kriging. As a result, it is indicated that estimated distribution by external drift kriging using scoping survey results with measurement errors is the same as that without measurement error. Estimation variance was increased with measurement errors. Therefore the evaluation method will be applied to determine the radioactivity distribution with uncertainty.
Shimada, Taro; Nabekura, Nobuhide*; Miwa, Kazuji; Takeda, Seiji
no journal, ,
It is necessary for confirmation of completion of decommissioning of nuclear facilities to comply with dose criteria for public using the land after site release, based on the radioactivity distribution at the land of the site. We are developing a methodology of public dose evaluation based on the survey results of evaluation of the radioactivity distribution. In this report, the external drift kriging method combined with scoping survey and sampling measurement were applied to 1km square area, and a cross validation method was applied to validate the evaluated distribution. Index of Mean Absolute Error is appropriate to evaluate the difference between evaluation and measurement. In addition, upper limit of 95% single side confidence interval for the evaluation of non-measured point was suggested to input for dose evaluation.
Miwa, Kazuji; Namekawa, Masakazu*; Shimada, Taro; Takeda, Seiji
no journal, ,
The distribution of surface soil contamination on the site of nuclear facilities after confirmation of the decommissioning may be changed by rainfall. In this study, the radionuclides migration model is developed to evaluate the radiation dose to the public including radionuclides distribution change. The result of radionuclides migration estimation on virtual site condition suggests that radionuclides which is migrated by surface water and soil migration gather in depression area. It is also shown that radionuclides migration on surface is more significant path to the ocean than radionuclides migration in groundwater. Based on these findings, it is suggested that the radiation dose considering change of radionuclides distribution may be larger than that from initial radionuclides distribution.
Jiang, X.*; Tamura, Kenji*; Asano, Maki*; Haruma, Toshikatsu; Takahashi, Junko*; Fukuyama, Kenjin; Yamaji, Keiko*
no journal, ,
no abstracts in English
