Abstract
The Consortium for Advanced Simulation of Light Water Reactors (CASL) Virtual Environment for Reactor Applications (VERA) offers unique capabilities to combine high-fidelity in-core radiation transport with temperature feedback using MPACT and CTF with a follow-on fixed source transport calculation using the Shift Monte Carlo code to calculate ex-core quantities of interest. In these coupled calculations, MPACT provides a fission source to Shift for the follow-on radiation transport calculation. In past VERA releases, MPACT passed a spatially dependent source without the energy distribution to Shift. Shift then assumed a 235U Watt spectrum to sample the neutron source energies. There were concerns that, in cases with burned or mixed oxide (MOX) fuel near the periphery of the core, the assumption of a 235U Watt spectrum for the source neutron energies would not be accurate for studying ex-core quantities of interest, such as pressure vessel fluence or detector response. Therefore, two additional options were implemented in VERA for Shift to sample neutron source energies: (1) a nuclide-dependent Watt spectra for 235U, 238U, 239Pu, and 241Pu, and (2) to use the standard 51-energy group MPACT spectrum. Results show that the 51-group MPACT spectrum is not suitable for ex-core calculations because the groups have been fine-tuned for in-core calculations. Differences in relative detector response due to 235U and nuclide-dependent Watt spectra sampling schemes were negligible; however, the use of nuclide-dependent Watt spectra for vessel fluence calculations was found to be important for fuel cycles with burned and fresh fuel.
Original language | English |
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Title of host publication | International Conference on Physics of Reactors |
Subtitle of host publication | Transition to a Scalable Nuclear Future, PHYSOR 2020 |
Editors | Marat Margulis, Partrick Blaise |
Publisher | EDP Sciences - Web of Conferences |
Pages | 326-333 |
Number of pages | 8 |
ISBN (Electronic) | 9781713827245 |
DOIs | |
State | Published - 2020 |
Event | 2020 International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future, PHYSOR 2020 - Cambridge, United Kingdom Duration: Mar 28 2020 → Apr 2 2020 |
Publication series
Name | International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future, PHYSOR 2020 |
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Volume | 2020-March |
Conference
Conference | 2020 International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future, PHYSOR 2020 |
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Country/Territory | United Kingdom |
City | Cambridge |
Period | 03/28/20 → 04/2/20 |
Funding
This research was supported by the Consortium for Advanced Simulation of Light Water Reactors (http://www.casl.gov), an Energy Innovation Hub (http://www.energy.gov/hubs) for Modeling and Simulation of Nuclear Reactors under US Department of Energy (DOE) Contract No. DE-AC05-00OR22725. This research also used resources of the Compute and Data Environment for Science (CADES) at ORNL, which is supported by the Office of Science of the US DOE. *Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
Keywords
- CASL
- Ex-core analysis
- Fission source spectrum
- Hybrid methods