An overview of the Cooperative IASCC Research (CIR) program

Irradiation-Assisted Stress Corrosion Cracking (IASCC) has affected reactor core internal structures fabricated from austenitic stainless steels in both Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR). The Cooperative IASCC Research (CIR) Program is an international research effort designed to address irradiation-assisted stress corrosion cracking (IASCC) in light water reactor (LWR) components. The objectives of the CIR program are to develop a mechanistic understanding of IASCC initiation and crack growth, to derive a predictive model of IASCC, if possible based on a mechanistic understanding, and thus to identify possible countermeasures to IASCC. It complements other more applied programs by concentrating on the underlying physical causes of IASCC. This paper provides an overview of the current status and achievements of the CIR program, which has been running since 1995. Two phases of the program have been completed and a final extension program is in progress which is scheduled to finish in 2008. The extent to which the CIR program has met its objectives, or will meet them with its current plans extending into 2008, is assessed. (author)