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DOE OSTI · 1907364

Uncertainty Analysis for a Criticality Benchmark [Slides]

Favorite, Jeffrey A.
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Abstract

This presentation discusses how KRUSTY was analyzed with LANL’s MCNP neutron transport code, Monte Carlo N-Particle. In the Monte Carlo method, neutrons are born in fission events and fly around the geometry having events (e.g., scatter, capture, fission, escape) according to the natural probabilities. “Natural probabilities” are given as neutron cross sections , which are measured and evaluated nuclear data. One of the goals of the benchmark project is to improve the nuclear cross sections (and the codes that use them). In this work, the response of interest is called k eff , which describes the neutron multiplication in a near critical system. Like most quantities, k eff is not measured directly; it is only inferred. In summation, MCNP results for k eff matched the measurements extremely well. The evaluated uncertainties are asymmetric and smaller than 0.00100 (e.g., + 0.00080 / – 0.00062). The largest uncertainties are due to alignment.

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS97 MATHEMATICS AND COMPUTINGIntegral ExperimentsNatural ProbabilitiesNeutron Cross SectionsNeutron MultiplicationNuclear Criticality Safety Program (NCSP)

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Favorite, Jeffrey A.. 2021-03-01. Uncertainty Analysis for a Criticality Benchmark [Slides]. https://doi.org/10.2172/1907364

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