[1I07-12] FP behavior

[1I08] Fundamental Research on Fission Product Chemistry

(2)The atmospheric effect on the Cs deposition behaviors onto stainless steels

*Kunihisa Nakajima¹, Eriko Suzuki¹, Masahiko Osaka¹ (1. Japan Atomic Energy Agency)

Keywords:cesium, stainless steel, chemisorption, revaporization

There are a large amount of stainless steels used for the reactor pressure vessel internals. So the cesium (Cs) deposition behavior might influence the Cs release and transport behaviors during a severe light water reactor accident. Thus, the atmospheric effect on the Cs deposition behaviors onto stainless steels exposed to cesium hydroxide (CsOH) vapor was investigated. As the results, the Cs deposited amounts under oxidizing conditions such as mixed gas of argon, steam, and hydrogen (Ar-H₂O-H₂) were found to increase compared with those under a reducing condition of Ar-H₂. Furthermore, the cross-sectional observation of the Cs deposited layers by using a SEM/EDS suggests that the revaporization of the deposited Cs occurs especially under the Ar-H₂ reducing condition.