Performance Evaluation of a Solidification Process for Highly Concentrated Radiation-Contaminated Surplus Soil

Abstract

To evaluate the performance of field-portable (360 mm D×360 mm H×800 mm W) and fixed-mount (1,880 mm D×2,140 mm H×9,085 mm W) filter presses for soil consolidation and volume reduction in the radiation-contaminated soil washing process, radiation assessment was conducted with soil from Fukushima contaminated with over 570,000 Bq/kg of radioactivity. The results were as follows. (1) During soil consolidation, the maximum core dose in the field-portable and fixed-mount types was evaluated respectively as 196 µSv/h and 60 µSv/h at the distance of 1 m from the core. (2) From these results, the maximum exposure dose in ordinary maintenance and inspection was evaluated as 48.1 mSv, exceeding the radiation protection guide level, and thus measures to reduce radiation exposure are required particularly in ordinary maintenance.