Continuous Casting of Metallic Nuclear Fuel Pins

Future nuclear power plant designs call for large numbers of metallic fuel pins made from uranium alloys. Existing methods for casting these pins are very slow and costly. This project aims to enable largescale production of metallic nuclear fuel by developing an innovative continuous casting process. We are developing a continuous casting method that uses innovative process equipment, instrumentation, and control algorithms to produce precision metal fuel pins at very low cost and with metallurgical properties that are optimal for nuclear fuel. We designed and built a facility for demonstrating the casting process, designed and built mechanisms that enable precise process control, and designed, built, and/or obtained critical components needed for continuous casting at a high rate. Phase II (still under way) will conclude by demonstrating that we can produce metallic pins at a high linear casting rate with the fine, equiaxed grain structure needed for good irradiation performance. We propose to augment Phase II by developing the technologies and processes needed to meet commercial requirements for metallic fuel pins. Technical objectives will be to: (1) produce pins that meet commercial dimensional requirements, (2) extend the existing process to enable continuous production of many multiple pins, (3) develop robotic technology for pin cutting and handling, (4) establish quality control procedures, and (5) begin to transfer the technology from current simulated fuel materials to UZr alloys. The work plan calls for modifying the Phase II casting facility to enable augmented capabilities; running pin casting experiments using CuNi alloys to achieve high rates of pin production while meeting dimensional requirements; designing and assembling robotic hardware for steady production and handling of multiple pins from a single crucible of molten material; developing inspection methods to validate the fabrication approach and establish quality control procedures; and beginning work to develop the necessary hightemperature materials that will enable casting pins from UZr alloys. The primary commercial application will be production of metallic fuel pins for prototype and commercial nuclear power plants. The public benefit will be a lowcost, reliable source of electric power that is produced by safe and environmentally benign power plants. 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, and can also be used for edgedefined, filmfed growth of crystals. Key Words Nuclear fuel fabrication, metallic nuclear fuel, continuous casting. Economical production methods for metal nuclear fuel are needed to support the development of safe and environmentally friendly nuclear power plants. This SBIR project aims to develop advanced technology for lowcost production of nuclear fuel from uranium alloys.