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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Latest News
NNSA awards BWXT $1.5B defense fuels contract
The Department of Energy’s National Nuclear Security Administration has awarded BWX Technologies a contract valued at $1.5 billion to build a Domestic Uranium Enrichment Centrifuge Experiment (DUECE) pilot plant in Tennessee in support of the administration’s efforts to build out a domestic supply of unobligated enriched uranium for defense-related nuclear fuel.
Brian J. Ade, Benjamin R. Betzler, Joseph R. Burns, Christopher W. Chapman, Jianwei Hu
Nuclear Science and Engineering | Volume 196 | Number 12 | December 2022 | Pages 1539-1558
Technical Paper | doi.org/10.1080/00295639.2022.2035157
Articles are hosted by Taylor and Francis Online.
Recent developments in manufacturing large metal hydrides are enabling their use as a moderator for advanced reactor designs. Yttrium hydride (YHx) is particularly attractive for small reactor designs because of its ability to retain a high hydrogen density at elevated temperatures. Design iteration for the Transformational Challenge Reactor (TCR), which uses a YH1.85 moderator, revealed positive moderator temperature coefficients. A positive temperature coefficient for YHx is expected regardless of the core design, however, the positive moderator coefficient exceeded that of the negative fuel temperature coefficient in some early TCR design iterations. The cause of the positive moderator coefficient is analyzed, and conditions for which positive temperature coefficients would be expected are identified for a number of fuel and moderator geometry layouts for dense tristructural isotropic/silicon carbide fuel and UO2 fuel.