Optimization of Once-Through Uranium Cycle for Pressurized Light Water Reactors

The optimum ²³⁵U enrichment of the uranium fuel for a once-through cycle for pressurized water reactors (PWRs) is ∼20%. Such an enrichment leads to a core design having the following major advantages in safety, economy, and uranium utilization over present standard designs. 1. There is a reduction in core volume by about a factor of 2, resulting in important savings in costs of core and pressure vessel. 2. Safety will be enhanced as a result of utilization of metallic fuel elements with much greater strength and a factor of 10 better heat conduction and less stored energy than standard ceramic fuel elements. The maximum temperature is 700°F below melting, as compared with 300°F for ceramic fuel. 3. Plutonium discharge is reduced by about a factor of 7. 4. Need for a soluble neutron-absorber control is eliminated. 5. While a detailed core design was beyond the scope of this work, a relatively simple fuel management scheme appears to be feasible which would reduce initial uranium ore requirements by ∼50% of that of standard PWRs and separative work by ∼35% reduce annual usage of uranium ore by ∼15% with a slight increase in separative work.