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Title: Advanced nodal neutron diffusion method with space-dependent cross sections: ILLICO-VX

Abstract

Advanced transverse integrated nodal methods for neutron diffusion developed since the 1970s require that node- or assembly-homogenized cross sections be known. The underlying structural heterogeneity can be accurately accounted for in homogenization procedures by the use of heterogeneity or discontinuity factors. Other (milder) types of heterogeneity, burnup-induced or due to thermal-hydraulic feedback, can be resolved by explicitly accounting for the spatial variations of material properties. This can be done during the nodal computations via nonlinear iterations. The new method has been implemented in the code ILLICO-VX (ILLICO variable cross-section method). Numerous numerical tests were performed. As expected, the convergence rate of ILLICO-VX is lower than that of ILLICO, requiring approx. 30% more outer iterations per k/sub eff/ computation. The methodology has also been implemented as the NOMAD-VX option of the NOMAD, multicycle, multigroup, two- and three-dimensional nodal diffusion depletion code. The burnup-induced heterogeneities (space dependence of cross sections) are calculated during the burnup steps.

Authors:
;
Publication Date:
Research Org.:
Univ. of Illinois, Urbana (USA)
OSTI Identifier:
6831090
Report Number(s):
CONF-8711195-
Journal ID: CODEN: TANSA; TRN: 88-031987
Resource Type:
Conference
Journal Name:
Trans. Am. Nucl. Soc.; (United States)
Additional Journal Information:
Journal Volume: 55; Conference: American Nuclear Society winter meeting, Los Angeles, CA, USA, 15 Nov 1987
Country of Publication:
United States
Language:
English
Subject:
22 GENERAL STUDIES OF NUCLEAR REACTORS; REACTOR PHYSICS; I CODES; NEUTRON DIFFUSION EQUATION; ACCURACY; BENCHMARKS; BURNUP; CROSS SECTIONS; GROUP THEORY; HEAT TRANSFER; HYDRAULICS; MULTIPLICATION FACTORS; NONLINEAR PROBLEMS; SPACE DEPENDENCE; COMPUTER CODES; DIFFERENTIAL EQUATIONS; ENERGY TRANSFER; EQUATIONS; FLUID MECHANICS; MATHEMATICS; MECHANICS; PHYSICS; 220100* - Nuclear Reactor Technology- Theory & Calculation

Citation Formats

Rajic, H L, and Ougouag, A M. Advanced nodal neutron diffusion method with space-dependent cross sections: ILLICO-VX. United States: N. p., 1987. Web.
Rajic, H L, & Ougouag, A M. Advanced nodal neutron diffusion method with space-dependent cross sections: ILLICO-VX. United States.
Rajic, H L, and Ougouag, A M. 1987. "Advanced nodal neutron diffusion method with space-dependent cross sections: ILLICO-VX". United States.
@article{osti_6831090,
title = {Advanced nodal neutron diffusion method with space-dependent cross sections: ILLICO-VX},
author = {Rajic, H L and Ougouag, A M},
abstractNote = {Advanced transverse integrated nodal methods for neutron diffusion developed since the 1970s require that node- or assembly-homogenized cross sections be known. The underlying structural heterogeneity can be accurately accounted for in homogenization procedures by the use of heterogeneity or discontinuity factors. Other (milder) types of heterogeneity, burnup-induced or due to thermal-hydraulic feedback, can be resolved by explicitly accounting for the spatial variations of material properties. This can be done during the nodal computations via nonlinear iterations. The new method has been implemented in the code ILLICO-VX (ILLICO variable cross-section method). Numerous numerical tests were performed. As expected, the convergence rate of ILLICO-VX is lower than that of ILLICO, requiring approx. 30% more outer iterations per k/sub eff/ computation. The methodology has also been implemented as the NOMAD-VX option of the NOMAD, multicycle, multigroup, two- and three-dimensional nodal diffusion depletion code. The burnup-induced heterogeneities (space dependence of cross sections) are calculated during the burnup steps.},
doi = {},
url = {https://www.osti.gov/biblio/6831090}, journal = {Trans. Am. Nucl. Soc.; (United States)},
number = ,
volume = 55,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1987},
month = {Thu Jan 01 00:00:00 EST 1987}
}

Conference:
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