Chemical trapping of Sr vapor species by Zircaloy cladding under a specific chemical condition

Mohamad, A.* ; Nakajima, Kunihisa  ; Suzuki, Eriko   ; Miwa, Shuhei  ; Osaka, Masahiko  ; Oishi, Yuji*; Muta, Hiroaki*; Kurosaki, Ken*

In the accident of Fukushima Daiichi Nuclear Power Station, formation of a volatile SrCl could have occurred by the sea-water injection into the core. This can cause the release of non-volatile group Sr from the fuel to induce chemical reactions with reactor structural materials, such as stainless steel and Zircaloy (Zry) cladding. Such reactions could cause the changes in distribution of Sr in the reactor. Chemical reactions between Sr species and Zry were therefore investigated experimentally. As the result, it can be said that Sr vapor species were chemically trapped right after the release from fuel. This trapping effect of Sr by Zry-cladding implies a possibility of preferable Sr retention in the oxide phase of debris.