WEAPONS-GRADE PLUTONIUM DISPOSITION IN PRESSURIZED-WATER REACTORS

Studies have been conducted to demonstrate that weapons-grade plutoniu m can be readily disposed of by utilizing it as a fuel in pressurized water reactors (PWR). The disposition can be achieved by first fabrica ting the weapons-grade plutonium into a mixed-oxide (MOX) fuel form an d then irradiating it in either advanced or existing PWRs to a deplete d level similar to commercial spent fuel. Preliminary neutronics studi es pertaining to safety-related core design using 100% weapons-grade M OX fuel are presented. The results demonstrate the feasibility of a sm all plutonium disposition reactor of 600-MW(electric) capacity called the PDR600, a large plutonium disposition reactor of 1400-MW(electric) capacity called the PDR1400, and a typical four-loop modified Westing house reactor. Feasible loading patterns are obtained for the initial and equilibrium cycles using discrete borosilicate glass burnable abso rbers and a heavy loading of zirconium diboride integralfuel burnable absorbers in every fuel rod. The preliminary core physics results incl ude information on soluble boron concentration, peaking factors, Doppl er and moderator reactivity coefficients, boron, xenon and control rod worths, shutdown margin and delayed neutron parameters. The core desi gn for weapons-grade plutonium disposition can be achieved with minimu m changes in the present safety and licensing criteria of advanced or existing PWRs.