PROCESS FOR PRODUCING LARGE GRAIN SIZE NUCLEAR FUEL PELLETS WITH LARGE MATRIX DENSITY

摘要

In the production of nuclear fuel pellets consisting essentially of oxides of uranium, or mixtures of these oxides with oxides of thorium or plutonium, by granulating the oxide powder, pressing the granulated powder into compacts and sintering the compacts, niobium pentoxide is added to the oxide power in sufficient quantity to encourage grain growth in the oxide compact during sintering and the sintering and other process parameters are adjusted so that no impurities are trapped in the sintering pellets which would prevent a high matrix density and grain size being obtained. Adjustment and control of the oxygen potential of the sintering atmosphere is proposed.