Manufacture of Metallic Fuel Pins With Advanced Geometries

New types of nuclear power plants are under development that will enable nuclear power to 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 pins made with annular geometries that reduce fuel temperature and swelling compared to solid pins. No method currently exists for producing large numbers of annular fuel pins. Creare proposes to develop an advanced, continuous casting method that uses innovative tooling, instrumentation, and process control technology to produce uranium alloy fuel pins with annular geometries that are optimized for future nuclear power plants. The method uses an innovative device to pull a casting directly from the surface of a pool of molten metal, using high-intensity cooling to solidify the pin as quickly as it emerges from the pool. Experiments demonstrated the feasibility of producing annular fuel pins using a continuous casting process. We designed and built key components of the continuous casting system and cast annular pins directly from a pool of molten metal at relatively low temperature. Data from these tests include videos of the casting process, temperature and casting rate data, and dimensions of the castings. In Phase II, we will develop advanced precision casting equipment that can be used to produce annular pins of metallic nuclear fuel. We will apply the designs and process parameters identified in Phase I to higher temperatures using a molten metal that more closely models nuclear fuel alloys. We will develop the equipment needed to produce the pins, run multiple series of fabrication experiments, and refine the design of the equipment based on the measured dimensions and metallurgical properties of the castings. Use of annular fuel pins 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 and reduced risk of nuclear materials proliferation. The technology we develop for precision control of the continuous casting process will also enable production of a wide range of metallic components for commercial applications. Creare will develop technology for production of uranium alloy fuel pins with unique shapes that are needed for next-generation nuclear power plants.