Comparison of homogenized and enhanced diffusion solutions of model PWR problems

Elmer E Lewis*, Micheal A. Smith

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Model problem comparisons in slab geometry are made between two forms of homogenized diffusion theory and enhanced diffusion theory. The pin-cell discontinuity factors for homogenized diffusion calculations are derived from homogenized variational nodal P1 response matrices and from standard finite differencing. Enhanced diffusion theory consists of applying quasi-reflected interface conditions to reduce variational nodal Pn response matrices to one degree of freedom per interface, without homogenization within the cell. As expected both homogenized diffusion methods preserve reaction rates exactly if the discontinuity factors are derived from the P 11 reference solutions. If no reference lattice solution is available, discontinuity factors may be approximated from single cells with reflected boundary conditions; the computational effort is then comparable to calculating the enhanced diffusion response matrices. In this situation enhanced diffusion theory gives the most accurate results and finite difference discontinuity factors the least accurate.

Original languageEnglish (US)
Title of host publicationInternational Conference on the Physics of Reactors 2012, PHYSOR 2012
Subtitle of host publicationAdvances in Reactor Physics
Pages705-714
Number of pages10
Volume1
StatePublished - Dec 6 2012
EventInternational Conference on the Physics of Reactors 2012: Advances in Reactor Physics, PHYSOR 2012 - Knoxville, TN, United States
Duration: Apr 15 2012Apr 20 2012

Other

OtherInternational Conference on the Physics of Reactors 2012: Advances in Reactor Physics, PHYSOR 2012
CountryUnited States
CityKnoxville, TN
Period4/15/124/20/12

Keywords

  • Discontinuity factors
  • Enhanced neutron diffusion
  • Homogenization
  • Response matrix

ASJC Scopus subject areas

  • Nuclear Energy and Engineering

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