Safe storage of zeolite adsorbents used for treatment of accident-generated water at Fukushima Daiichi Power Station

Yamagishi, Isao ; Nagaishi, Ryuji ; Terada, Atsuhiko  ; Kamiji, Yu; Kato, Chiaki   ; Morita, Keisuke ; Nishihara, Kenji  ; Tsubata, Yasuhiro   ; Ji, W.*; Fukushima, Hisashi*; Sato, Seichi*; Okagaki, Yuria*; Denton, M.*

Since the accident at Fukushima Daiichi Nuclear Power Station, a large amount of radioactive contaminated water has been generated to cool damaged reactor cores. Adsorption of cesium with zeolite-like media was employed for treatment of this contaminated saline water. As spent zeolite media are highly radioactive, their safe storage is a pressing issue. Japan Atomic Energy Agency has extensively conducted R&D on the management of secondary wastes produced by the operation of the treatment system. Subjects on the safe storage of spent zeolites include the analysis of their characteristics and the evaluation of effectiveness of the present safety measures in consideration of decay heat emission and hydrogen generation by water radiolysis as well as durability of vessels exposed to saline. Preliminary results obtained are described in the present paper.