Lightbridge Corporation and Enfission, LLC have demonstrated the manufacturing process and fabrication of Lightbridge Fuel surrogate rods in a length that could be usable in NuScale Power's small modular reactors (SMR).Lightbridge Fuel technology features a helically-twisted shape and unique metallic composition (Image: Lightbridge)
The demonstration included the production of several coextruded rods using an internally developed and patented coextrusion process, Lightbridge said. The fuel rod design is expected to increase core performance, extend core life, lessen the number of refueling outages, and offer reduced levelised cost of electricity.
The fuel rods, which are 6 feet (1.8 metres) in length were coextruded from billets contained in a zirconium canister and resulted in a bonded cladding surrounding the surrogate fuel material core. The surrogate materials were designed to simulate the flow stresses, including temperatures and extrusion pressures, expected in the manufacture of the Lightbridge Fuel rods using a uranium-zirconium alloy.
Lightbridge Corporation and Enfission President and CEO Seth Grae said the rods were produced in the USA, using the companies' patented technology and process. The successful demonstration marked a major milestone for Lightbridge and Enfission, representing "first reduction to practice" for the proprietary manufacturing process and confirming the feasibility of fabricating rods to 6 feet in length, he said. "We are now moving rapidly towards a similar demonstration of full-length (i.e. 12 feet) coextruded rods for the existing US fleet of large commercial nuclear power plants and we look forward to providing further updates," he said.
Demonstration of the coextrusion manufacturing process follows a Memorandum of Understanding between NuScale and Enfission in May 2019, under which the parties agreed to collaborate on the development of research and testing programs to explore the application of the Lightbridge Fueltechnology in NuScale's SMR design.
Lightbridge fuel uses a helically-twisted shape and unique metallic composition which the company says can significantly reduce fuel operating temperatures, improve the fuel's structural integrity and enhance its response to abnormal events. Enfission - a joint venture of Lightbridge Corporation and Framatome - was set up in January 2018 to commercialise nuclear fuel assemblies based on this technology.
Researched and written by World Nuclear News