Soil and waste generated by decontamination have been sealed in containers such as large weatherproof sandbags and flexible container bags (Fig. 1) according to guidelines 1) made by the Japanese government and tentatively stored at temporary storage sites. These containers are temporary materials, and it was initially assumed that the use period would be around 3 years. But in fact, at many temporary storage sites, they had been used for 3 years or longer, which raised concern over their durability. Therefore, the tensile test was conducted (Fig. 2) with storage containers that had been actually used at temporary storage sites to assess the strength variation for a long term.

As a result of the test, it was found that as long as the containers were in the environment shielded with water-impermeable sheets or the like to block sunlight, even if the containers had been used for 7.3 years at the maximum, the strength exceeded the standard strength of new containers (Fig. 3). Additionally, based on aging deterioration of tensile strength, it was estimated that they would withstand storage for around 10 years.

Fig.1　Storage containers (left: large weatherproof sandbags, right: flexible container bags)

Fig.2　Tensile test

Fig.3　Tensile strength of flexible container bags (light-shielded storage)

More（Japanese only）

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Reference

1. 福島県環境創造センター研究部(2024): 調査研究成果報告書～除染に関する調査研究～フェーズ2 令和元年度(2019年度)～令和3年度(2021年度).
   https://www.fukushima-kankyosozo.jp//lancelot/common_files/images/public/2024040101.pdf (2024.11.18アクセス)