Advances in Water Chemistry for Crack Mitigation and Dose Rate Reduction of BWRs with no Impact on Fuel Performance

The chemistry of BWR primary water is determined by 1) soluble/insoluble impurities in the feedwater, 2) species (O2, H2 and H2O2) generated by the radiolysis of water in the reactor core, 3) deposition and release of soluble/insoluble species on fuel, and 4) removal of reactor water impurities through the clean-up system. The challenge faced by the BWR industry is to balance these processes to maintain water chemistry within operating guidelines to optimize the performance of the BWR. Typically, BWR primary water is largely oxidizing due to the presence of O2 and H2O2 in the reactor water. The oxidizing nature of the water increases the electrochemical corrosion potential (ECP) of internal metal surfaces in the positive direction that in turn makes materials susceptible to intergranular stress corrosion cracking (IGSCC).