[1M04-07] Water chemistry and Corrosion for LWR

11:40 AM - 11:55 AM JST(2:40 AM - 2:55 AM UTC)

[1M07] Development of chemical decontamination method for carbon steel (2)Development of decomposition of decontaminants and purification methods

*Yuto Kato¹, Hideyuki Hosokawa¹, Takashi Ohira², Shintaro Yanagisawa², Masahiko Kazama³ (1. Hitachi, 2. HGNE, 3. Kurita Water Industries)

Keywords:

Chemical decontamination,Carbon steel,Corrosion,Formic acid,Ascorbic acid

In pipes of reactor water cleanup system and residual heat removal system, radionuclides deposit and cause radiation exposure during in-service inspections. Since their pipes are made of carbon steel, we have been developing a chemical decontamination method with high decontamination effect for carbon steel. The chemical decontamination has three processes: (1) dissolution process, (2) decomposition process, and (3) purification process. Previously, we confirmed that high decontamination effect with decontaminants using formic acid, ascorbic acid, and corrosion inhibitor in the process (1). In this study, we investigated processes (2) and (3) by laboratory test. The method to decompose and purify the decontaminants while suppressing corrosion was investigated since suppressing corrosion is important in addition to decontamination effect.