Pages 181-182
The SCPR is expected to be an innovative nuclear power system with considerably higher thermal efficiency and smaller specific volume. Material compatibility for core components, in particular fuel claddings, is thought to be a key factor for the viability of SCPR Material screening is performed through literature survey, simulated irradiation tests, corrosion tests, SCC tests, and mechanical tests under SCPR conditions. Candidate materials in this study are selected from materials used in three industrial fields : fossil power plant, waste processing plant and nuclear power plant. This paper describes the results of electron beam irradiation tests for the assessment of irradiation resistance and SCC tests with austenitic stainless steels. Simulated irradiation tests were performed for austenitic stainless steels, nickel base alloys and titanium alloys at 563K, 723K and 823K up to five displacement per atom (dpa) using a high-energy transmission electron microscope (HVTEM) with the electron beam of 1000kV. The susceptibility to intergranular stress corrosion cracking (IGSCC) was evaluated by slow strain rate tests (SSRTs), which were performed using an SCPR test loop at the strain rate of 4X(10)^<-7>/s, the temperatures from 563 to 823K and the pressure of 25MPa in high purity water with 8 ppm dissolved oxygen (DO). The results for sensitized Type 304 SS indicated that the IGSCC susceptibility decreased with increasing temperature. It was found the upper limit of IGSCC susceptibility existed for sensitized type 304 SS at around 673K, above which IGSCC susceptibility disappeared.
