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

Published

June 1, 2019

Author(s)

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

Abstract

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.

Citation

Annals of Nuclear Energy

Volume

128

Pub Type

Journals

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Keywords

Low-Enriched Uranium, Research Reactor, Neutronics Performance Characteristics

Citation

, 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], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926546 (Accessed October 14, 2025)