Change of corrosion characteristics of SUS304L and Zircaloy-4 by an immersion test under the pre-heat treatment and constant potential

Yamashita, Shinichiro   ; Osaka, Masahiko  

The decommissioning work of Fukushima Dai-ichi Nuclear Power Plant (1F-NPP) is intensively being promoted according to the Mid-and-long Term Roadmap towards the Decommissioning of 1F-NPP units 1-4. Many research and development works are underway in order to ensure the progress of the decommissioning work. One of the R&D programs relates to the removal of fuel assemblies (FAs) from the spent fuel pool (SFP), in which the seawater was injected as an emergency counter-measure for fuel cooling during the accident. For the anticipation of the long term integrity of irradiated FA structural materials that experienced a diluted seawater exposure part of a fundamental research plan was described to support the estimation of the long-term possible influences of corrosive factors on the component materials of FAs. In this study, whether or not acceleration of corrosion occurred was investigated by the immersion test under constant potential for SUS304L and Zircaloy-4.