Applications of a systematic homogenization theory for nodal diffusion methods

Conference · Wed Jan 01 04:00:00 EST 1992 · Transactions of the American Nuclear Society; (United States)

OSTI ID:6683313

Zhang, Hong-bin; Dorning, J J ^[1]

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1. Univ. of Virginia, Charlottesville (United States)

The authors recently have developed a self-consistent and systematic lattice cell and fuel bundle homogenization theory based on a multiple spatial scales asymptotic expansion of the transport equation in the ratio of the mean free path to the reactor characteristics dimension for use with nodal diffusion methods. The mathematical development leads naturally to self-consistent analytical expressions for homogenized diffusion coefficients and cross sections and flux discontinuity factors to be used in nodal diffusion calculations. The expressions for the homogenized nuclear parameters that follow from the systematic homogenization theory (SHT) are different from those for the traditional flux and volume-weighted (FVW) parameters. The calculations summarized here show that the systematic homogenization theory developed recently for nodal diffusion methods yields accurate values for k[sub eff] and assembly powers even when compared with the results of a fine mesh transport calculation. Thus, it provides a practical alternative to equivalence theory and GET (Ref. 3) and to simplified equivalence theory, which requires auxiliary fine-mesh calculations for assemblies embedded in a typical environment to determine the discontinuity factors and the equivalent diffusion coefficient for a homogenized assembly.

• OSTI ID: 6683313
• Report Number(s): CONF-921102--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 66
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220100* -- Nuclear Reactor Technology-- Theory & Calculation
CALCULATION METHODS
CROSS SECTIONS
DIFFERENTIAL EQUATIONS
EQUATIONS
HOMOGENIZATION METHODS
MATHEMATICAL MODELS
NEUTRON DIFFUSION EQUATION
NEUTRON FLUX
NEUTRON TRANSPORT THEORY
NODAL EXPANSION METHOD
RADIATION FLUX
REACTOR LATTICES
TRANSPORT THEORY