[3E04-05] Behavior of Radioactive Nuclides 2

[3E04] Study and evaluation of cesium chemisorption behavior onto steel under simulated nuclear reactor severe accident environment in 400^oC.

*Nabaichuan Li¹, Ken Kurosaki¹, Kunihisa Nakajima², Eriko Suzuki² (1. Kyoto Univ., 2. JAEA)

Keywords:Fukushima daiichi, BWR retirement, cesium chemisorption, steel

The chemical adsorption(chemisorption) behavior of cesium hydroxide vapor on stainless steel (SS304) has been reported that occurs above 600 ° C. However, it was reported that recent study discovered cesium ferrate (CsFeO2) can be synthesized from mixture of CsOH and goethite (FeO(OH)) at approximately 200° C. Therefore, considering the accident of Fukushima Daiichi Nuclear Power Station, cesium chemisorption may occur below 600 ° C, namely, not only in the RPV but also in the PCV. Hence, in this study, Raman spectroscopic analysis, Scanning electronic microscopy(SEM) and X-ray diffraction (XRD) were applied on carbon steel and SS304, which is the structural material of PCV and RPV respectively. As a result, CsFeO2 was found as the major chemisorption product on both carbon steel and SS304.