Thermal Diffusion of Oxygen in PuO_2-y

Oxygen redistribution in hypo stoichiometric plutonium-dioxide has been investigated in out-of-pile experiments. The heat of transport of oxygen thermal diffusion depends on the O/Pu ratio and increases from 0 to -28 kcal/mole when the O/Pu ratio increases from 1.65 to 1.95. The result is comparable to that obtained with mixed oxides, thus indicating the heat of transport of solid-state thermal diffusion to be independent of plutonium concentration in the mixed oxide.