Langevin equation approach to reactor noise analysis: stochastic transport equation

Conference · Tue Jan 01 04:00:00 EST 1991 · Transactions of the American Nuclear Society; (United States)

OSTI ID:7168774

Akcasu, A Z; Stolle, A M ^[1]

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

This paper is concerned with an application of the Langevin equation method to the study of fluctuations in the space- and velocity-dependent neutron density, as well as in the detector outputs, in nuclear reactors. The Langevin equation in this case is the stochastic linear neutron transport equation with a space- and velocity-dependent random neutron source, often referred to as the noise equivalent source (NES). The power spectral density (PSD) of the NES is evaluated in nuclear engineering applications by adopting a generalization of the Shottky formula. In this paper, the authors extend calculations to include the space and velocity dependence of neutron density by starting from the stochastic transport equation and the stochastic detection rate equations within the detectors. In addition, they discuss the implementation of the Langevin equation approach at different levels of approximation and explicitly obtain the stochastic one-speed transport and one-group P{sub 1} equations by first integrating the transport equation over speed and then eliminating in the angular dependence by spherical harmonic expansion.

• OSTI ID: 7168774
• Report Number(s): CONF-911107--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 63
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220100* -- Nuclear Reactor Technology-- Theory & Calculation
EQUATIONS
FUNCTIONS
LANGEVIN EQUATION
MARKOV PROCESS
NEUTRAL-PARTICLE TRANSPORT
NEUTRON SOURCES
NEUTRON TRANSPORT
PARTICLE SOURCES
PHYSICS
POWER DENSITY
PROBABILITY
RADIATION SOURCES
RADIATION TRANSPORT
REACTOR NOISE
REACTOR PHYSICS
SCHOTTKY EFFECT
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SPACE DEPENDENCE
SPECTRAL DENSITY
SPECTRAL FUNCTIONS
STOCHASTIC PROCESSES
TIME DEPENDENCE