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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.
S. Patnaik, B. W. Spencer, E. Roberts, T. M. Besmann, T. W. Knight
Nuclear Science and Engineering | Volume 195 | Number 12 | December 2021 | Pages 1307-1326
Technical Paper | doi.org/10.1080/00295639.2021.1932223
Articles are hosted by Taylor and Francis Online.
A variety of normal operation and accident scenarios can generate thermal stresses large enough to cause cracking in ceramic fuel pellets. Cracking in fuel pellets can lead to reduced heat removal, higher centerline temperatures, and localized stress in the cladding—all which impact fuel performance. It is important to experimentally characterize the thermal and mechanical behaviors in the pellet both before and after cracking, which would help to improve cracking models in fuel performance codes such as BISON. However, in-reactor observation and measurement of cracking are very challenging due to the harsh environment and design of the fuel rods involved. Recently, an experimental pellet-cracking test stand was developed for separate-effects testing of pellet cracking under normal operations and accident temperature conditions using thermal imaging to capture the pellet surface temperatures in order to evaluate the thermal stresses and optical imaging to capture the evolution of cracking in real time. Experiments were performed using depleted uranium dioxide (UO2) pellets, which are useful for collecting valuable data for development and validation of cracking models. A combination of induction and resistance heating was used to create thermal gradients similar to those seen in a reactor environment. Characterization of the pellets was conducted both before and after cracking. The cracking patterns are moderately different from those expected in a typical reactor because of the variations in the thermal conditions and pellet microstructures. However, when the actual conditions of these experiments are reproduced in computational models with sufficient precision, such out-of-pile testing on UO2 pellets provides relevant data for modeling purposes.