Variational nodal perturbation calculations using simplified spherical harmonics

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:471374

Laurin-Kovitz, K; 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). Dept. of Mechanical Engineering

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, we 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.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 471374
• Report Number(s): ANL/RA/CP--90340; CONF-961103--32; ON: DE97003875
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
66 PHYSICS
99 GENERAL AND MISCELLANEOUS
NEUTRON TRANSPORT
NODAL EXPANSION METHOD
PERTURBATION THEORY
REACTOR PHYSICS
SPHERICAL HARMONICS
VARIATIONAL METHODS