Biases in Monte Carlo eigenvalue calculations

Journal Article · Sun May 01 04:00:00 EDT 1994 · Nuclear Science and Engineering; (United States)

OSTI ID:7110595

Gelbard, E M ^[1]; Gu, A G ^[2]

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1. Argonne National Lab., IL (United States). Reactor Analysis Division
2. Mississippi State Univ., Mississippi State, MS (United States). Mechanical and Nuclear Engineering

The derivation of the standard expression for the Monte Carlo eigenvalue bias is reviewed. It is noted that the bias is due to the repeated normalization of the fission source by the eigenvalue. This normalization can be partially or completely eliminated, but when this is done, the variance in the eigenvalue may increase unacceptably. Thus, it seems impractical, in general, to eliminate the bias in this way. Next, the Brissenden-Garlick relation between eigenvalue bias and variance is rederived for nonanalog tracking and estimation. From this relation, it is shown that the eigenvalue bias under normal'' conditions is smaller than the eigenvalue's standard deviation. In this sense, the bias is not significant, so that it is not crucially important to eliminate or to estimate it.

• OSTI ID: 7110595
• Journal Information: Nuclear Science and Engineering; (United States), Journal Name: Nuclear Science and Engineering; (United States) Vol. 117:1; ISSN NSENAO; ISSN 0029-5639
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220100* -- Nuclear Reactor Technology-- Theory & Calculation
663610 -- Neutron Physics-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CALCULATION METHODS
EIGENVALUES
FISSION
KINETICS
MONTE CARLO METHOD
NEUTRAL-PARTICLE TRANSPORT
NEUTRON TRANSPORT
NEUTRON TRANSPORT THEORY
NUCLEAR REACTIONS
RADIATION TRANSPORT
REACTOR KINETICS
TRANSPORT THEORY