Abstract A computationally efficient and effective multi-level coarse mesh finite difference (CMFD) acceleration is proposed using the local two-node nodal expansion method for solving the three-dimensional multi-group neutron diffusion equation. The multi-level CMFD acceleration method consists of two essential features: (1) a new one-group (1G) CMFD linear system is established by using cross sections, flux and current information from the multi-group (MG) CMFD to accelerate the MG CMFD calculation, (2) an adaptive Wielandt shift method is proposed to accelerate the inverse power iteration of 1G CMFD in order to provide an accurate estimate of the eigenvalue at the beginning of the iteration for both 1G and MG CMFD linear system. Additionally, a nodal discontinuity factor and a diffusion coefficient correction factor are defined to achieve equivalence of the 1G and MG CMFD system. The accuracy and acceleration performance of multi-level CMFD are examined for a variety of well-known multi-group benchmarks problems. The numerical results demonstrate that superior accuracy is achievable and the multi-level CMFD acceleration method is efficient, particularly for the larger, multi-group systems.
[1]
Elmer E Lewis,et al.
Benchmark on deterministic 3-D MOX fuel assembly transport calculations without spatial homogenization
,
2004
.
[2]
T. Downar,et al.
A 2-D/1-D Transverse Leakage Approximation Based on Azimuthal, Fourier Moments
,
2017
.
[3]
Thomas J. Downar,et al.
Implementation of Two-Level Coarse-Mesh Finite Difference Acceleration in an Arbitrary Geometry, Two-Dimensional Discrete Ordinates Transport Method
,
2008
.
[4]
Dmitriy Y. Anistratov,et al.
Nonlinear Diffusion Acceleration Method with Multigrid in Energy for k-Eigenvalue Neutron Transport Problems
,
2016
.
[5]
Han Gyu Joo,et al.
Two-Level Coarse Mesh Finite Difference Formulation with Multigroup Source Expansion Nodal Kernels
,
2008
.
[6]
Jurij Kotchoubey,et al.
POLCA-T Neutron Kinetics Model Benchmarking
,
2015
.