Control of Grain Properties and Slug Geometry for High-Performance Metallic Fuel

C56-40v-272647Next-generation nuclear power plants can provide a large-scale source of environmentally benign power generation while improving safety and minimizing proliferation risks. For best performance, these reactors will require large numbers of uranium alloy fuel slugs produced with metallurgical properties that enable reliable, long-term operation. No method currently exists for high-volume production of metal fuel slugs with suitable metallurgy. Creare proposes to develop an innovative, continuous casting process to produce uranium alloy fuel slugs from a highly supercooled melt. Supercooling enables the metal to solidify with an equiaxed grain structure for best irradiation behavior. Continuous casting will enable large-scale, high-volume production rates. In Phase I, we will demonstrate the key step of the continuous casting process. We will use Cu/Ni alloys to simulate U/Zr and show by test that a continuous process can be used to produce solid casting from a supercooled melt. We will validate the process by producing samples and using metallography to assess grain structure. Metal fuel slugs with equiaxed grain structure will reduce cost and improve the safety and performance of future reactors. The public benefit will be low-cost electricity that is produced by safe and environmentally benign power plants with reduced risk of nuclear materials proliferation. The technology we develop for control of the fuel slug metallurgy will also enable production of stronger, high-performance components for applications such as aluminum alloy automotive and aerospace structures.