In-pile IASCC test programme in the Halden reactor

The Halden Project is currently undertaking specific investigations aimed at evaluating the effects of environmental parameters on Light Water Reactor (LWR) materials corrosion behavior by means of in-pile tests performed in facilities simulating both PWR and BWR environments. One such investigation is aimed at exploring Irradiation Assisted Stress Corrosion Cracking (IASCC) phenomena which affected the in-core structural component materials of LWRs. The main objective of the study is to obtain crack growth data on reactor internals materials in environments similar to those found in operating BWRs. In particular, the investigation is aimed at determining whether Hydrogen Water Chemistry (HWC) can effectively suppress IASCC in core component materials. The test facility, which simulates the radiation, water chemistry and thermal-hydraulic conditions typical of those found in commercial BWRs, is designed to operate under Normal Water Chemistry as well as Partial and Full Hydrogen Water Chemistry. A total of the ten Double Cantilever Beam (DBC) test specimens, all of which are wedge loaded to a well-defined stress intensity, are being utilized in the study. The DCBs, fabricated from stainless steels and nickel base alloys commonly found in commercial reactors, are instrumented for on-line crack propagation monitoring by the DC potential drop technique