CHEMICAL-POTENTIAL OF CARBON IN THE SYSTEM U-PU-C-O-N - MEASUREMENTS AND CALCULATION

The carbon potential of (U,Pu) mixed carbides with Pu/(U + Pu) ratios of 0.55 and 0.70 was measured in the temperature range 973 to 1173 K b y employing a methane-hydrogen gas equilibration technique. The techni que was validated by measuring the Gibbs energy of formation of WC. Th e compatibility of the mixed carbides with the stainless steel clad wa s analysed by using the measured carbon potentials. The carbon potenti als of mixed carbides of other compositions were calculated theoretica lly in order to assess their compatibility. The calculations assume id eal solution behavior for all the solid solutions present in the U-Pu- C-O-N system.