Plutonium free uranium fuel in PWR concepts : neutronic aspects

In order to have an optimum Plutonium consumption Plutonium Free Uranium fuels have been studied. For a MOX fuel loaded in a standard PWR the Plutonium and Uranium consumption are, respectively, about 60 and 50 Kg/TWhe (electrical TerraWatts per hour). Thus, by suppressing the Uranium support one can expect to double the Plutonium consumption. However, by suppressing the Uranium isotopes, the neutronic behaviour is degraded : the reactivity coefficients do not allow a definite conclusion on the feasibility of this concept. Thus, different core concepts are proposed in order to enhance the feasibility of the use of such fuel in a PWR. The characteristics of these cores are presented in terms of mass balance and core feasibility. (author)