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Conference Spotlight
2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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Latest News
The progress so far: An update on the Reactor Pilot Program
It has been about three months since the Department of Energy named 10 companies for its new Reactor Pilot Program, which maps out how the DOE would meet the goal announced by executive order in May of having three reactors achieve criticality by July 4, 2026.
W. Bennett, R. G. McClarren
Nuclear Science and Engineering | Volume 199 | Number 1 | April 2025 | Pages S808-S817
Research Article | doi.org/10.1080/00295639.2024.2333092
Articles are hosted by Taylor and Francis Online.
Verification solutions for uncertainty quantification (UQ) are presented for time-dependent transport problems where , the scattering ratio, is uncertain. The method of polynomial chaos expansions is employed for quick and accurate calculation of the quantities of interest (QoIs), and uncollided solutions are used to treat part of the uncertainty calculation analytically. We find that approximately six moments in the polynomial expansion are required to represent the solutions to these problems accurately. Additionally, the results show that if the uncertainty interval spans c = 1, which means it is uncertain whether the system is multiplying or not, the confidence interval will grow in time. Finally, since the QoI is a strictly increasing function, the percentile values are known and can be used to verify the accuracy of the expansion. These results can be used to test UQ methods for time-dependent transport problems.