Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Hybrid super homogenization and discontinuity factor method for continuous finite element diffusion

Journal Article · · Annals of Nuclear Energy (Oxford)
 [1];  [1];  [1];  [1];  [1];  [1];  [1]
  1. Idaho National Lab. (INL), Idaho Falls, ID (United States)
+ Show Author Affiliations
This paper presents a novel homogenization equivalence technique aiming to simultaneously leveragethe simplicity of the Super Homogenization (SPH) method to reproduce reference reaction rates andthe ability to preserve reference leakage rates at desired surfaces through Discontinuity Factors (DF).The need for this new class of methods arises from the inability of the current state-of-the-art SPH technology to properly reproduce the reactor multiplication factor for problems with significant leakage. This work shows that this defect lies in the use of normalization factors in the SPH algorithm: while they are necessary with purely reflecting problems to ensure uniqueness of the solution, they introduce homogenization inconsistencies if at least one vacuum boundary condition is present. Two solutions to this problem are presented in this work: (i) to simply remove the normalization factor or (ii) to introduce additional degrees of freedom in the form of DFs in such a way that the normalization factors can still constrain the problem. While the former clearly offers unrivaled simplicity and can lead to very satisfactory results for leakage-dominated cores or if spatial restriction of the SPH regions is applied – as demonstrated for the High Temperature Test Reactor, the latter is more robust and does not require to scale the fission terms with the reference eigenvalue.
Research Organization:
Idaho National Laboratory (INL), Idaho Falls, ID (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE)
Grant/Contract Number:
AC07-05ID14517
OSTI ID:
1498269
Alternate ID(s):
OSTI ID: 22846603
Report Number(s):
INL/JOU--18-51060-Rev000
Journal Information:
Annals of Nuclear Energy (Oxford), Journal Name: Annals of Nuclear Energy (Oxford) Journal Issue: C Vol. 128; ISSN 0306-4549
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

Figures / Tables (11)

Figure 1(p. 23)figure Figure 1
Figure 2(p. 24)figure Figure 2
Figure 3(p. 25)figure Figure 3
Table 1(p. 26)table Table 1
Figure 4(p. 29)figure Figure 4
Figure 5(p. 30)figure Figure 5
Figure 6(p. 31)figure Figure 6
Table 2(p. 34)table Table 2
Table 3(p. 35)table Table 3
Table 4(p. 36)table Table 4
Table 5(p. 37)table Table 5

Similar Records

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
97 MATHEMATICS AND COMPUTING
Discontinuity Factors
Finite Element Method
High Temperature Test Reactor (HTTR)
Multiphysics Object Oriented Simulation Environment (MOOSE)
Rattlesnake Transport Code
Super Homogenization (SPH)