Study on long-term storage method for spent zeolite vessels; Establishment of code system for analyzing hydrogen diffusion, burning and explosion, and its impact

Terada, Atsuhiko  ; Takegami, Hiroaki ; Kamiji, Yu; Hino, Ryutaro

In the accident of Fukushima Daiichi NPP, the high-level contaminated water processing system with zeolite vessel. is operating for treatment of contaminated water mixed with seawater. A spent KURION zeolite vessel is detached from the water processing system and brought to exclusive storage yards. Although water in the vessel is drained before storage, combustible hydrogen could be produced via radiolysis of water absorbed in the zeolite. An analytical code system available for hydrogen diffusion, burning and explosion, and its impact has been prepared in order to confirm a safe long-term storage method of the vessel. The code system consists of several analytical codes such as general-purpose CFD code FLUENT, deflagration analytical code FLACS and detonation analytical code AUTODYN and interfaces connecting each code. This report presents an outline of analytical code system including interfaces, and introduces preliminary analytical study.