ESTIMATION OF CONTAMINATION PROFILE OF RADIOACTIVE METAL WASTE IN PWRS

摘要

The contamination conditions were investigated for the stainless steel specimens taken out from the piping in PWR. SEM, XRD and Ge γ-Spectrometry were applied to measure the contamination conditions of specimen. It was found that an oxide covers the contaminated surface; the oxide is composed of spinel type oxide, and has a largely part of radioactivity of specimen. Chemical technique and Ge γ-Spectrometry were applied to measure the contamination profile. It was found that after base metal separation of approximately 1.0 μm depth, the residual activity concentration is reduced under the detection limit. The thin depth of the contamination is interpreted as the low temperature of system environment.