## 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 P_{1} response matrices and from standard finite differencing. Enhanced diffusion theory consists of applying quasi-reflected interface conditions to reduce variational nodal P_{n} 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 language | English (US) |
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Title of host publication | International Conference on the Physics of Reactors 2012, PHYSOR 2012 |

Subtitle of host publication | Advances in Reactor Physics |

Pages | 705-714 |

Number of pages | 10 |

Volume | 1 |

State | Published - Dec 6 2012 |

Event | International Conference on the Physics of Reactors 2012: Advances in Reactor Physics, PHYSOR 2012 - Knoxville, TN, United States Duration: Apr 15 2012 → Apr 20 2012 |

### Other

Other | International Conference on the Physics of Reactors 2012: Advances in Reactor Physics, PHYSOR 2012 |
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Country/Territory | United States |

City | Knoxville, TN |

Period | 4/15/12 → 4/20/12 |

## Keywords

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

## ASJC Scopus subject areas

- Nuclear Energy and Engineering