TY - JOUR
T1 - Multiphysics modeling of two-phase film boiling within porous corrosion deposits
AU - Jin, Miaomiao
AU - Short, Michael
N1 - Funding Information:
This research is supported by CASL (Consortium for Advanced Simulation of LWRs), under grant number 4000102892 . The authors also wish to express great thanks to the MOOSE development team at the Idaho National Laboratory (INL) for suggestions in MAMBA code development.
Publisher Copyright:
© 2016 Elsevier Inc.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - Porous corrosion deposits on nuclear fuel cladding, known as CRUD, can cause multiple operational problems in light water reactors (LWRs). CRUD can cause accelerated corrosion of the fuel cladding, increase radiation fields and hence greater exposure risk to plant workers once activated, and induce a downward axial power shift causing an imbalance in core power distribution. In order to facilitate a better understanding of CRUD's effects, such as localized high cladding surface temperatures related to accelerated corrosion rates, we describe an improved, fully-coupled, multiphysics model to simulate heat transfer, chemical reactions and transport, and two-phase fluid flow within these deposits. Our new model features a reformed assumption of 2D, two-phase film boiling within the CRUD, correcting earlier models' assumptions of single-phase coolant flow with wick boiling under high heat fluxes. This model helps to better explain observed experimental values of the effective CRUD thermal conductivity. Finally, we propose a more complete set of boiling regimes, or a more detailed mechanism, to explain recent CRUD deposition experiments by suggesting the new concept of double dryout specifically in thick porous media with boiling chimneys.
AB - Porous corrosion deposits on nuclear fuel cladding, known as CRUD, can cause multiple operational problems in light water reactors (LWRs). CRUD can cause accelerated corrosion of the fuel cladding, increase radiation fields and hence greater exposure risk to plant workers once activated, and induce a downward axial power shift causing an imbalance in core power distribution. In order to facilitate a better understanding of CRUD's effects, such as localized high cladding surface temperatures related to accelerated corrosion rates, we describe an improved, fully-coupled, multiphysics model to simulate heat transfer, chemical reactions and transport, and two-phase fluid flow within these deposits. Our new model features a reformed assumption of 2D, two-phase film boiling within the CRUD, correcting earlier models' assumptions of single-phase coolant flow with wick boiling under high heat fluxes. This model helps to better explain observed experimental values of the effective CRUD thermal conductivity. Finally, we propose a more complete set of boiling regimes, or a more detailed mechanism, to explain recent CRUD deposition experiments by suggesting the new concept of double dryout specifically in thick porous media with boiling chimneys.
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U2 - 10.1016/j.jcp.2016.03.013
DO - 10.1016/j.jcp.2016.03.013
M3 - Article
AN - SCOPUS:84963978847
SN - 0021-9991
VL - 316
SP - 504
EP - 518
JO - Journal of Computational Physics
JF - Journal of Computational Physics
ER -