Grant: NSERC/NRCan/AECL Generation IV Energy Technologies Program

The successful design and operation of a supercritical water-cooled reactor (SCWR) will ultimately be determined by the choice of materials for in-core and out-of-core components and the water chemistry strategies employed to minimize corrosion and degradation. Also related to corrosion of key components is the input of corrosion-products to the coolant that will lead to their transport and deposition in the reactor core and downstream components. This is highly undesirable due to their potential activation in the neutron field of the reactor core and subsequent transport downstream leading to radiation fields on out-of-core components. Using the UNB SCW test loop, this program will investigate the corrosion and degradation mechanisms (general corrosion and stress-corrosion cracking - SCC) on selected materials under simulated operating conditions expected in a SCWR; namely, temperatures up to 625 degC and pressures of ~ 25 MPa in nominally pure water with various concentrations of dissolved oxygen and hydrogen in the water. Additional experiments will be run in the UNB SCW test loop to evaluate the extent and kinetics of corrosion-product deposition that will occur in the SCWR core and the effects of minor impurities such as chloride, sulfate and lead that may be present in an operating reactor.