Variationally derived coarse mesh methods using an alternative flux representation

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:459201

Wojtowicz, G; Holloway, J P ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States)

Investigation of a previously reported variational technique for the solution of the 1-D, 1-group neutron transport equation in reactor lattices has inspired the development of a finite element formulation of the method. Compared to conventional homogenization methods in which node homogenized cross sections are used, the coefficients describing this system take on greater spatial dependence. However, the methods employ an alternative flux representation which allows the transport equation to be cast into a form whose solution has only a slow spatial variation and, hence, requires relatively few variables to describe. This alternative flux representation and the stationary property of a variational principle define a class of coarse mesh discretizations of transport theory capable of achieving order of magnitude reductions of eigenvalue and pointwise scalar flux errors as compared with diffusion theory while retaining diffusion theory`s relatively low cost. Initial results of a 1-D spectral element approach are reviewed and used to motivate the finite element implementation which is more efficient and almost as accurate; one and two group results of this method are described.

• OSTI ID: 459201
• Report Number(s): CONF-950420--
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
FINITE ELEMENT METHOD
ONE-GROUP THEORY
REACTOR LATTICES
VARIATIONAL METHODS