Variational nodal perturbation calculations using simplified spherical harmonics

Journal Article · Tue Dec 31 04:00:00 EST 1996 · Transactions of the American Nuclear Society

OSTI ID:426384

Kovitz, K L; Palmiotti, G ^[1]; Lewis, E E ^[2]

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1. Argonne National Lab., IL (United States)
2. Northwestern Univ., Evanston, IL (United States)

The simplified spherical harmonics (SP{sub N}) method has been used as an approximation to the transport equation in a number of situations. Recently, the SP{sub N} method has been formulated within the framework of the variational nodal method (VNM). Implementation in the VARIANT code indicated that for many two- and three-dimensional problems, near P{sub N} accuracy can be obtained at a fraction of the cost. Perturbation methods offer additional computational cost reduction for reactor core calculations and are indispensable for performing a variety of calculations, including sensitivity studies and the breakdown by components of reactivity worths. Here, the authors extend the perturbation method developed for the VNM in the full P{sub N} approximation to treat simplified spherical harmonics. The change in reactivity predicted by both first-order and exact perturbation theory using the SP{sub N} approximation is demonstrated for a benchmark problem and compared to diffusion and full P{sub N} estimates.

• OSTI ID: 426384
• Report Number(s): CONF-961103--
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 75; ISSN TANSAO; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
66 PHYSICS
COMPUTERIZED SIMULATION
NEUTRON TRANSPORT THEORY
NODAL EXPANSION METHOD
PERTURBATION THEORY
REACTIVITY WORTHS
REACTOR CORES
SPHERICAL HARMONICS METHOD
VARIATIONAL METHODS