In the latest MCRE development, INL reported that the research team, after five years of effort, has perfected the fuel-making process. The team was successful in converting more than 90 percent of the metal uranium feedstock into a compound that dissolves in the molten salt to create usable fuel for the reactor.
The effort: Scientists have been working on the fuel-making process since 2020, designing special equipment and methods for the required salt synthesis in INL’s Fuels and Applied Science Building at the lab’s Materials and Fuels Complex. Depleted uranium was used in experiments as the team tested and refined the process to avoid the costs of using expensive high-enriched uranium.
Their work progressed over the years from being able to make only 2 to 3 ounces of reactor fuel at a time to making more than 190 ounces of fuel in a single batch.
Baking a cake: MCRE project director Nick Smith said of the accomplishment, “After years of experimentation and revision, we finally found the right process to reach the perfect yield. It takes a special kind of perseverance to keep working the problem when there is no guarantee that you will find a solution.”
MCRE technical lead Bill Phillips compared the challenges faced by the team to trying to come up with the perfect recipe for baking a cake. “Nobody has ever made this amount of uranium chloride before,” he said. “We had to develop the process from scratch.”
New goal: Although INL characterizes the “development of uranium chloride fuel salt for MCRE [as] a significant milestone that could feed the energy needs of the future,” Phillips points out that the research team now needs to achieve its new goal of demonstrating the full-scale production of enriched fuel MCRE salt, and the scientists need to make five batches of it by October. “We’re almost at the moment where we can bake the cake,” he said.
INL’s ultimate goal is to have MCRE be operational by 2028. It will then become the first reactor experiment deployed at the test bed of the Laboratory for Operation and Testing in the United States (LOTUS).
RP3C presentation: In January 2024, for the American Nuclear Society’s Risk-Informed, Performance-Based Principles and Policy Committee’s (RP3C’s) Community of Practice, Brandon Chisholm, an advanced nuclear R&D engineer at Southern Company, presented “Development of a RIPB Safety Case for TerraPower’s MCRE.” Chisholm’s presentation is available on YouTube.
