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

11:10 AM - 11:25 AM JST(2:10 AM - 2:25 AM UTC)

[1M05] Evaluation of KOH as a pH control agent of PWR primary system(2) Evaluation of the effect of KOH on PWSCC initiation

*Kenta Kakitani¹, Yusuke Nakano², Wataru Sugino², Kenji Sato¹, Yuichi Shimizu¹ (1. MHI, 2. JAPC)

Keywords:

PWR,water chemistry,KOH,LiOH,Ni-based alloy,SCC

LiOH enriched in ⁷Li isotope is added to primary cooling water of PWR. Due to the limited number of countries producing isotopically enriched LiOH and the high cost of procurement, KOH is studied as a potential alternative to enriched LiOH. In this study, we aim to investigate the influence of KOH on SCC initiation of Ni-based alloys. Constant load tests at 360°C for Ni-based alloy X-750 were conducted. As a result, no significant changes were observed in the SCC initiation susceptibility between LiOH chemistry (2 or 3.5 ppm as Li) and KOH chemistry (same molar concentration as LiOH).