Experimental and thermodynamic investigation of Cs compounds after reaction with stainless steel and metallic debris during a severe accident

Pshenichnikov, A. ; Zubekhina, B. ; Ogi, Hiroshi  

The oral presentation will describe recent activities of JAEA in the framework of the collaboration project between JAEA and Tokyo institute of technology to investigate an interaction of Cs compounds (CsOH, CsI) with stainless steel 316L, simulated metallic debris obtained from the CLADS-MADE tests with prototypic BWR bundle materials under postulated conditions of an accident in Unit 2. A large number of laboratory small-scale tests using TG DTA equipment and these debris have been performed. The conditions were chosen to cover a range of temperatures and debris compositions which could potentially emerge in a RPV of the 1F. In particular, appearance, elemental and phase composition of new-formed phases were confirmed. It was established that under the accident conditions Cs can penetrate the oxide layers much easier, while the metallic bulk of debris cannot be penetrated.