Book Description
A specimen of cast thorium-5 wt% plutonium and one of thorium-10 wt% plutonium were irradiated to total atom burnups of 1.9 and 2.6%, respectively, at maximum fuel temperatures of approximately 450 deg C. Both alloys displayed excellent dimensional stability with volume increases of 0.8 and 1.2% per atom per cent burnup, respectively. Three cold-rolled specimens of zirconium-5 wt% plutonium and one cold-rolled specimen of zirconium-7 wt% plutonium were also irradiated. The zirconium- plutonium alloy specimens all showed extremely poor dimensional stability, with anisotropic elongations ranging from approximately 100 to 500%. The irradiation growth coefficients for these specimens ranged from 90 to 210 microinches per inch per atom per cent burnup. The poor dimensional stability of the zirconium-plutonium alloy specimens is attributed to a highly preferred grain orientation that presumably developed during cold rolling.
