Swelling, irradiation creep and growth of pure rhenium irradiated with fast neutrons at 1030-1330 deg. C

This paper discusses the results of two series of experiments conducted on pure hcp rhenium in the EBR-II and FFTF fast reactors. In FFTF, density change data were derived from open tubes and solid rods irradiated at temperatures and fluences in the range of 1020-1250 deg. C and 4.4-8.3x1022 n cm-2, respectively (E > 0.1 MeV). Both density change and diametral change data were obtained from pressurized tubes irradiated in EBR-II to ∼0.65 and ∼5.1x1022 n cm-2 at temperatures between 1030 deg. C and 1330 deg. C. Analysis of the data shows that four concurrent processes contribute to the radiation-induced strains observed in these experiments. These are void swelling, transmutation-induced densification via production of osmium, irradiation creep and irradiation growth