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Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
James S. Warsa, Jeffery D. Densmore, Anil K. Prinja, Jim E. Morel
Nuclear Science and Engineering | Volume 166 | Number 1 | September 2010 | Pages 36-47
Technical Paper | doi.org/10.13182/NSE09-36
Articles are hosted by Taylor and Francis Online.
Spatially analytic SN solutions currently exist only under very limited circumstances. For cases in which analytical solutions may not be available, one can turn to manufactured solutions to test the properties of spatial transport discretization schemes. In particular, we show it is possible to use a manufactured solution to conduct such tests in the thick diffusion limit, even though the computed solution is independent of the problem characteristics. We show that a diffusion limit scaling with a manufactured solution source term results in an expression that is valid in the diffusion limit, though it is not of the standard form used in asymptotic diffusion limit analysis. We then derive a necessary, but not sufficient, condition that must be satisfied in order for a spatial discretization of the transport equation to preserve the thick diffusion limit. This condition is stated in terms of the difference between a numerically computed scalar flux solution compared against a known scalar flux. For a sufficiently diffusive problem and optically thick mesh cells, the necessary condition states that if a spatial discretization of the SN equations has the thick diffusion limit, the norm of the difference in the two solutions must converge to zero with decreasing mesh cell spacing. Based on the first observation that the diffusion limit holds for a manufactured solution source term, the known solution can conveniently be taken to be a manufactured solution in a mesh refinement numerical experiment to check whether a spatial discretization satisfies this condition. We present computational examples that verify our analysis and illustrate the expediency of this approach.