A Pressurized Water Reactor Design for Plutonium Incineration: Fuel Cycle Options

The possibility exists of utilizing pressurized water reactor (PWR) power plants of current technology for efficient and cost-competitive incineration of excess plutonium. Several plutonium-based fuel cycle options were considered, i.e., pure ²³⁹Pu or reactor-grade plutonium as a fissile component and natural uranium or thorium as a fertile component of the fuel. A typical PWR was chosen as the base for detailed analysis and comparison of all investigated fuel cycle options. A series of calculations was carried out for each of the fuel cycle options generating “equilibrium” cycles of equal length. Results of the design analysis and comparison of main performance parameters were used to compare different fuel options. Material mass balances were calculated to evaluate the plutonium incineration potential of the considered options. A potential of efficient reduction of excess plutonium was demonstrated for all considered fuel options. The thorium-based fuel cycles were found especially effective for destruction of fissile isotopes of plutonium (>1000 kg/yr). This was partially compensated by the buildup of ²³³U isotope. One of the important conclusions of this work is that significant amounts of fissile plutonium may be incinerated in thorium-based cycles and that ²³³U may be denatured by addition of modest amounts of natural uranium. Preliminary economic evaluations indicate that plutonium incineration may be carried out in existing PWRs without economic penalty and may, therefore, present a viable alternative to other plutonium disposition methods.