Effects of irradiation temperature, fluence, and heating rate on postirradiation flow properties of cladding under simulated temperature transient heating and deformation conditions

Irradiation temperature, fluence, and heating rate effects on plastic flow and failure properties of fast reactor cladding were investigated by heating internally pressurized specimens until failure occurred. Specimens tested were from 20 percent cold-worked Type 316 stainless steel cladding, irradiated in the experimental breeder reactor II (EBR-II) at temperatures to 7200C and fluences to 1023 neutrons (n)/cm2(E>0.1 MeV). A decrease of transient failure temperature with increasing irradiation temperature was observed at the ''standard'' heating rate of 5.6 C0/s. This effect became more pronounced for irradiation temperatures above 6000C. Transient failure temperatures also generally decreased with increasing fluence for tests performed at the standard heating rate. 5 refs