BWR hydrogen water chemistry guidelines: 1987 Revision

Boiling water reactors (BWRs) have experienced stress corrosion cracking in the reactor cooling system piping resulting in adverse impacts on plant availability and personnel radiation exposure. The BWR Owners Group for IGSCC Research and EPRI have sponsored a major research and development program to provide remedies for this stress corrosion cracking problem. Results from this program show that the likelihood of cracking depends on reactor water chemistry (particularly on the concentrations of ionic impurities and oxidizing radiolysis products such as oxygen) as well as on material condition and stress level. Tests have demonstrated that the concentration of oxidizing radiolysis products in the recirculating reactor water of a BWR can be reduced substantially by injecting hydrogen into the feedwater. This report presents suggested generic hydrogen water chemistry specifications, discusses the proposed water chemistry limits, suggests responses to out-of-specification water chemistry, discusses available chemical analysis methods as well as data management and surveillance schemes, and details the management philosophy required to successfully establish and implement a hydrogen water chemistry control program. In addition to pipe cracking, fuel performance and effects on shutdown and operation radiation fields were considered in developing the feedwater and reactor water chemistry specifications presented in the body of the report. An appendix contains recommendations for water quality of auxiliary systems. 8 refs., 24 figs., 9 tabs