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Title: A deterministic study of deficiencies in the Wigner-Seitz cell approximation

Abstract

Monte Carlo methods are extremely powerful and heavily utilized for many applications in nuclear criticality safety. Accurate criticality calculations are possible because of the global nature of neutron multiplication. The stochastic approach has limitations, however, and is not appropriate for specialized applications that require differential fluxes or accurate neutron density distributions. The NEW Transport Algorithm (NEWT) computer code, developed at Oak Ridge National Laboratory (ORNL), has the ability to closely model nonorthogonal two-dimensional geometries that are traditionally left to Monte Carlo analyses. Because it is based on the discrete ordinates formalism, it can provide an accurate prediction of neutron distributions in space and energy. However, unlike most discrete ordinates methods, NEWT solves fluxes on a grid of arbitrary polygons, which can be used to closely approximate complex configurations. Results of multidimensional depletion and sensitivity/uncertainty analyses will be reported in the future after significant testing has been completed. Herein the authors focus on a recent study performed at ORNL to understand discrepancies noted for the Wigner-Seitz cell approximation often applied in lattice calculations.

Authors:
 [1]
  1. Oak Ridge National Lab., TN (United States)
Publication Date:
OSTI Identifier:
678140
Report Number(s):
CONF-990605-
Journal ID: TANSAO; ISSN 0003-018X; TRN: 99:009125
Resource Type:
Journal Article
Resource Relation:
Journal Name: Transactions of the American Nuclear Society; Journal Volume: 80; Conference: 1999 annual meeting of the American Nuclear Society (ANS), Boston, MA (United States), 6-10 Jun 1999; Other Information: PBD: 1999
Country of Publication:
United States
Language:
English
Subject:
21 NUCLEAR POWER REACTORS AND ASSOCIATED PLANTS; 99 MATHEMATICS, COMPUTERS, INFORMATION SCIENCE, MANAGEMENT, LAW, MISCELLANEOUS; MONTE CARLO METHOD; N CODES; DISCRETE ORDINATE METHOD; NEUTRON TRANSPORT; REACTOR LATTICES; MIXED OXIDE FUELS; MULTIPLICATION FACTORS; BURNUP; PWR TYPE REACTORS

Citation Formats

DeHart, M.D. A deterministic study of deficiencies in the Wigner-Seitz cell approximation. United States: N. p., 1999. Web.
DeHart, M.D. A deterministic study of deficiencies in the Wigner-Seitz cell approximation. United States.
DeHart, M.D. Wed . "A deterministic study of deficiencies in the Wigner-Seitz cell approximation". United States. doi:.
@article{osti_678140,
title = {A deterministic study of deficiencies in the Wigner-Seitz cell approximation},
author = {DeHart, M.D.},
abstractNote = {Monte Carlo methods are extremely powerful and heavily utilized for many applications in nuclear criticality safety. Accurate criticality calculations are possible because of the global nature of neutron multiplication. The stochastic approach has limitations, however, and is not appropriate for specialized applications that require differential fluxes or accurate neutron density distributions. The NEW Transport Algorithm (NEWT) computer code, developed at Oak Ridge National Laboratory (ORNL), has the ability to closely model nonorthogonal two-dimensional geometries that are traditionally left to Monte Carlo analyses. Because it is based on the discrete ordinates formalism, it can provide an accurate prediction of neutron distributions in space and energy. However, unlike most discrete ordinates methods, NEWT solves fluxes on a grid of arbitrary polygons, which can be used to closely approximate complex configurations. Results of multidimensional depletion and sensitivity/uncertainty analyses will be reported in the future after significant testing has been completed. Herein the authors focus on a recent study performed at ORNL to understand discrepancies noted for the Wigner-Seitz cell approximation often applied in lattice calculations.},
doi = {},
journal = {Transactions of the American Nuclear Society},
number = ,
volume = 80,
place = {United States},
year = {Wed Sep 01 00:00:00 EDT 1999},
month = {Wed Sep 01 00:00:00 EDT 1999}
}