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DOE OSTI · 23203850

P{sub N} source expansion nodal method in MPACT for boiling water reactors

Choi, Sooyoung·Kochunas, Brendan
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Abstract

This paper describes the one-node P{sub N}-Source Expansion Nodal Method (SENM) axial solver for the 2D/1D method recently implemented in MPACT to support Boiling Water Reactors (BWR) analysis. Since the BWR has a more complicated design and strong burnable absorber, the existing PN-Nodal Expansion Method (NEM) axial solver in MPACT may not be sufficient to accurately represent the intranodal flux and source profiles for BWRs. The one-node P{sub N}-SENM has been implemented in this work to reduce the axial spatial discretization error for BWRs. From numerical results, we verify that the P{sub N}-SENM can improve the accuracy of the pin power prediction, and confirm that P{sub N}-SENM can use more than a 1.5 times larger axial mesh size than P{sub N}-NEM to have similar accuracy for the BWR GE14 3D assembly problem. (authors)

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21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTSBWR TYPE REACTORSNEUTRON TRANSPORT THEORYNODAL EXPANSION METHODNUMERICAL SOLUTIONVALIDATION

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Choi, Sooyoung, Kochunas, Brendan. 2022-07-01. P{sub N} source expansion nodal method in MPACT for boiling water reactors. https://www.osti.gov/biblio/23203850

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