Four different species of beryllium: S-200F (vacuum hot pressed, 1.2 wt% BeO), S-200FH (hot isostatic pressed, 0.9 wt% BeO); S-65 (vacuum hot pressed, 0.6 wt% BeO) and S-65H (hot isostatic pressed, 0.5 wt% BeO) are fabricated by Brush Wellman. Three batches of the berylliums are investigated, a neutron irradiated batch, a thermal control batch and a reference batch. Neutron irradiation is performed at nominal temperature conditions of 200, 400 and 600 degrees C up to a fluence of 1.5 x 10(25) n m(-2) (E(n) > 1 MeV). Based on the tensile tests results, the S-65 VHP and the S-200 HIP show slightly higher elongation and strength after irradiation. Based on the swelling determination, S-200 swells less than S-65. In conclusion, the S-200 HIP might tentatively be selected.
