HEAT TRANSFER ACROSS ANNULI IN GAS BONDED URANIUM DIOXIDE FUEL ELEMENTS

摘要

The apparent thermal conductivity of UO2pellet, stainless steel clad, fuel element specimens with helium-filled annuli was measured. The helium gap between the pellets and cladding varied from 0.0035 to 0.0095 in. Due to unanticipated temperature drops in the experimental assembly, the effect of the helium annulus was uncertain.nAn improved experimental method is described, which would eliminate limitations in the present experiment, and should yield definitive results as to the effect of the size of the helium annulus.