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Neutronic Performance Characteristics of Different LEU Fuels in a Proposed NIST Research Reactor



Danyal J Turkoglu, Zeyun Wu, Robert E. Williams, Thomas Henderson Newton


As a potential replacement for the National Bureau Standards Reactor (NBSR) at the U.S. National Institute of Standards and Technology (NIST), a conceptual design of a new reactor with a horizontally-split core using low-enriched uranium silicide dispersion (U3Si2/Al) fuel has recently been studied. In this paper, the neutronics calculations with low-enriched U-Mo fuels (U-10Mo monolithic and U-7Mo/Al dispersion) and U3Si2/Al fuel were compared with the objective of identifying the best fuel candidate for the reactor for practical operations and maximum cold neutron production. For comparisons, fuel inventories for multi-cycle equilibrium cores were calculated for each fuel based on a 30 day reactor cycle at 20 MW thermal power. With its very high uranium density, the potential to load more uranium in the core with U-10Mo monolithic fuel was explored with test cases using an alternate fuel management scheme, a higher power level (30 MW), or a longer cycle (45 days). The research results indicate similar neutronics performance characteristics of the three LEU fuel options in the proposed NIST reactor. However, the ability to load more fuel in the reactor with the U-10Mo option allows more flexibility in the reactor design and could lead to other optimizations that maximize cold neutron production.
Annals of Nuclear Energy


Low-Enriched Uranium, Research Reactor, Neutronics Performance Characteristics


, D. , Wu, Z. , , R. and , T. (2019), Neutronic Performance Characteristics of Different LEU Fuels in a Proposed NIST Research Reactor, Annals of Nuclear Energy, [online], (Accessed April 22, 2024)
Created June 1, 2019, Updated February 27, 2020