The effect of potassium hydroxide primary water chemistry on the IASCC behavior of 304 stainless steel

Abstract Western Pressurized Water Reactors (PWRs) are considering the replacement from lithium hydroxide (LiOH) to potassium hydroxide (KOH) as a pH balancing agent in primary water due to the higher cost and lower availability of 7Li. This study qualified the irradiation-assisted stress corrosion cracking (IASCC) propagation compatibility of baffle plate materials in simulated PWR primary water with LiOH or KOH chemistries. Samples extracted from two pieces of Type 304 stainless steel baffle plates with different dose (9 and 15 dpa) were investigated. Water chemistries were switched between LiOH (1.3–2 ppm) and KOH (7.2 to 11.3 ppm) at constant pH during the crack growth rate (CGR) test on a sample, thus the effect of water chemistry was determined directly without other variations. Results indicate that there is no discernable effect on the CGR behavior by changing from LiOH to KOH.