Proliferation Resistant Fuel for Pebble Bed Modular Reactors

We show that it is possible to denature the plutonium produced in pebble bed modular reactors by doping the nuclear fuel with either 3050 ppm of ²³⁷Np or ~2100 ppm of isotopic composition of Am. A correct choice of these isotope concentrations yields denatured plutonium with isotopic ratio ²³⁸Pu/Pu 6%, for the entire fuel burnup cycle. The penalty for introducing these isotopes into the nuclear fuel is a subsequent shortening of the fuel burnup cycle, with respect to a nondoped reference fuel cycle, by ~40 and 20 full-power days, respectively, which correspond to 4.1 and 2.0 GW(d)/ton reduction in fuel discharge burnup.