TY - GEN
T1 - On the effect of fine-scale radial void distributions on assembly criticality and pin power distribution
AU - Price, Dean
AU - Gacek, Andrew
AU - Kozlowski, Tomasz
AU - Radaideh, Majdi I.
N1 - Publisher Copyright:
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).
PY - 2020
Y1 - 2020
N2 - The assumption that void fraction, and by extension coolant density, is uniform in the radial direction is a common approximation used in lattice physics simulations. In this study, models without uniform radial void fraction are used and lattice criticality and pin powers are investigated in two ways. One way uses hypothetical models that reflect extreme radial void distributions; modifications such as uniform radial pin enrichment and the removal of gadolinium rods are included in these models as well. Experimentally-determined boiling water reactor radial void distributions are also replicated in neutronics models using Serpent 2. It is found in the hypothetical models that the presence of gadolinium rods has a large effect on the interaction between lattice criticality and radial void distribution. It was also found that considering experimental radial void fraction distributions had the largest effect on the pin power of the rods containing gadolinium. Furthermore, it is observed that considering realistic radial void distributions, in general, decreased lattice criticality. The reason can be attributed that to the passive negative-feedback design of light water reactors. These are useful findings because calculation of more accurate peaking factors can lead to efficient and yet safer reactor operation.
AB - The assumption that void fraction, and by extension coolant density, is uniform in the radial direction is a common approximation used in lattice physics simulations. In this study, models without uniform radial void fraction are used and lattice criticality and pin powers are investigated in two ways. One way uses hypothetical models that reflect extreme radial void distributions; modifications such as uniform radial pin enrichment and the removal of gadolinium rods are included in these models as well. Experimentally-determined boiling water reactor radial void distributions are also replicated in neutronics models using Serpent 2. It is found in the hypothetical models that the presence of gadolinium rods has a large effect on the interaction between lattice criticality and radial void distribution. It was also found that considering experimental radial void fraction distributions had the largest effect on the pin power of the rods containing gadolinium. Furthermore, it is observed that considering realistic radial void distributions, in general, decreased lattice criticality. The reason can be attributed that to the passive negative-feedback design of light water reactors. These are useful findings because calculation of more accurate peaking factors can lead to efficient and yet safer reactor operation.
KW - Boiling Water Reactor
KW - Criticality
KW - Radial Void Distribution
KW - Serpent 2
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U2 - 10.1051/epjconf/202124706054
DO - 10.1051/epjconf/202124706054
M3 - Conference contribution
AN - SCOPUS:85108403354
T3 - International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future, PHYSOR 2020
SP - 1395
EP - 1402
BT - International Conference on Physics of Reactors
A2 - Margulis, Marat
A2 - Blaise, Partrick
PB - EDP Sciences - Web of Conferences
T2 - 2020 International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future, PHYSOR 2020
Y2 - 28 March 2020 through 2 April 2020
ER -