On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation
In this work we present a scheme for computing temperature-dependent unresolved resonance region cross sections in Monte Carlo neutron transport simulations. This approach relies on the generation of equiprobable cross section magnitude bands on an energy-temperature mesh. The bands are then interpo...
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| Format: | Article |
| Language: | en_US |
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American Nuclear Society (ANS)
2017
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| Online Access: | http://hdl.handle.net/1721.1/109720 https://orcid.org/0000-0002-2542-1149 https://orcid.org/0000-0003-1459-7672 https://orcid.org/0000-0003-2497-4312 |
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| author | Brown, Forrest B. Walsh, Jonathan Alan Forget, Benoit Robert Yves Smith, Kord S. |
| author2 | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Brown, Forrest B. Walsh, Jonathan Alan Forget, Benoit Robert Yves Smith, Kord S. |
| author_sort | Brown, Forrest B. |
| collection | MIT |
| description | In this work we present a scheme for computing temperature-dependent unresolved resonance region cross sections in Monte Carlo neutron transport simulations. This approach relies on the generation of equiprobable cross section magnitude bands on an energy-temperature mesh. The bands are then interpolated in energy and temperature to obtain a cross section value. This is in contrast to the typical procedure of pre-generating probability tables at all temperatures present in the
simulation. As part of this work, a flexible probability table generation capability is integrated into the continuous-energy neutron transport code OpenMC [1]. Both single-level and multi-level Breit-Wigner formalisms are supported, as is modeling of the resonance structure of competitive reactions. A user-specified cross section band tolerance is enabled with
batch statistics. Probability tables are generated for all 268 ENDF/B-VII.1 [2] isotopes that have an unresolved resonance region evaluation. Integral benchmark simulations of the Big Ten critical assembly show that, for a system that is sensitive to the unresolved resonance region, a temperature interval of ∼200 K around 293.6 K is sufficient to reproduce the keff
value that is obtained with probability tables generated exactly at room temperature. A finer mesh of < 50 K is required to reproduce some cross section values at the common target relative difference of 0.1% |
| first_indexed | 2024-09-23T15:07:34Z |
| format | Article |
| id | mit-1721.1/109720 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:07:34Z |
| publishDate | 2017 |
| publisher | American Nuclear Society (ANS) |
| record_format | dspace |
| spelling | mit-1721.1/1097202022-10-02T00:45:20Z On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation Brown, Forrest B. Walsh, Jonathan Alan Forget, Benoit Robert Yves Smith, Kord S. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Walsh, Jonathan Alan Forget, Benoit Robert Yves Smith, Kord S. In this work we present a scheme for computing temperature-dependent unresolved resonance region cross sections in Monte Carlo neutron transport simulations. This approach relies on the generation of equiprobable cross section magnitude bands on an energy-temperature mesh. The bands are then interpolated in energy and temperature to obtain a cross section value. This is in contrast to the typical procedure of pre-generating probability tables at all temperatures present in the simulation. As part of this work, a flexible probability table generation capability is integrated into the continuous-energy neutron transport code OpenMC [1]. Both single-level and multi-level Breit-Wigner formalisms are supported, as is modeling of the resonance structure of competitive reactions. A user-specified cross section band tolerance is enabled with batch statistics. Probability tables are generated for all 268 ENDF/B-VII.1 [2] isotopes that have an unresolved resonance region evaluation. Integral benchmark simulations of the Big Ten critical assembly show that, for a system that is sensitive to the unresolved resonance region, a temperature interval of ∼200 K around 293.6 K is sufficient to reproduce the keff value that is obtained with probability tables generated exactly at room temperature. A finer mesh of < 50 K is required to reproduce some cross section values at the common target relative difference of 0.1% 2017-06-07T19:59:50Z 2017-06-07T19:59:50Z 2016-08 2016-05 Article http://purl.org/eprint/type/ConferencePaper 9781510825734 http://hdl.handle.net/1721.1/109720 Walsh, Jonathan A. et al. "On-The-Fly Doppler Broadening of Unresolved Resonance Region Cross Sections via Probability Band Interpolation." Physics of Reactors 2016 (PHYSOR 2016): Unifying Theory and Experiments in the 21st Century, 1-5 May, 2016, Sun Valley Resort, Idaho, USA, American Nuclear Society, 2016. https://orcid.org/0000-0002-2542-1149 https://orcid.org/0000-0003-1459-7672 https://orcid.org/0000-0003-2497-4312 en_US http://www.proceedings.com/30896.html Proceedings of Physics of Reactors 2016 (PHYSOR 2016): Unifying Theory and Experiments in the 21st Century Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf American Nuclear Society (ANS) Prof. Forget via Chris Sherratt |
| spellingShingle | Brown, Forrest B. Walsh, Jonathan Alan Forget, Benoit Robert Yves Smith, Kord S. On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation |
| title | On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation |
| title_full | On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation |
| title_fullStr | On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation |
| title_full_unstemmed | On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation |
| title_short | On-the-fly doppler broadening of unresolved resonance region cross sections via probability band interpolation |
| title_sort | on the fly doppler broadening of unresolved resonance region cross sections via probability band interpolation |
| url | http://hdl.handle.net/1721.1/109720 https://orcid.org/0000-0002-2542-1149 https://orcid.org/0000-0003-1459-7672 https://orcid.org/0000-0003-2497-4312 |
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