Study on dose assessment in surrounding environment of the Tono Mine associated with closure activity

Sasao, Eiji   

Dose assessment associated with closure activity of the Tono Mine has been performed. Localities for dose evaluation are selected at the Higashihoragawa and Hiyoshigawa. Evaluation scenarios are classified into the base and alternative scenarios. Parameters are set-up based on the existing data. But the range and uncertainty of parameters are considered in the alternative cases. Maximum exposure doses of the base and alternative scenarios are 0.08 mSv/year, and 0.09 mSv/year including direct and skyshine rays and exposure of exhalated radon at the Higashihoragawa. On the alternative cases, exposure doses are calculated as 0.05-0.14 mSv/year in the base and alternative scenarios. At the Hiyoshigawa, maximum exposure dose is less than 0.001 mSv/year for the base scenario, and 0.001 mSv/year for the alternative scenario. On the alternative cases, maximum exposure doses are less than 0.001 mSv/year for the base scenario and 0.0006-0.002 mSv/year for the alternative scenario.