Presentation Information
[1G05]Evaluation of steam oxidation mechanism of Zircaloy in the presence of NaCl
*Ryota Nakazawa1, Ayumi Itoh1, Mutsumi Hirai2, Masato Mizokami2 (1. Science Tokyo, 2. TEPCO HD)
Keywords:
Fukushima Daiichi Nuclear Power Station,severe accident,U-containing particle,Zircaloy,steam oxidation
A part of the U-containing particles from Fukushima Daiichi Nuclear Power Station seemed to have formed via evaporation-condensation and contained small amount of Zr, implying Zr may have moved to gas phase despite its low volatility in metallic or oxide forms. This study focused on the possibility that NaCl deposited on metallic zircaloy during seawater injection in the accident and contributed to generation of Zr-containing aerosols during steam oxidation of zircaloy. The effect of NaCl deposits on the steam oxidation rate of zircaloy, the microstructure and the aerosols generation were experimentally investigated. As a result, ZrO2 powder was observed on zircaloy surface and was estimated to have been formed by steam oxidation reaction including NaCl.