Whole-Core Heterogeneous Transport Calculations and Their Comparison with Diffusion Results
Conference
·
OSTI ID:786859
Recently the method of characteristics (MOC) has been considered as an effective methodology in lattice calculations. This method gives accurate solutions in complex geometries and strong absorber problems. With increasingly more heterogeneous reactor cores such as a mixed-oxide (MOX) fuel-loaded core or a burnable absorber-loaded core, the limitations due to homogenization and diffusion theory are evident, and the need for whole-core heterogeneous transport calculations is becoming greater. The CRX code based on the MOC is extended to treat whole-core heterogeneous calculation. Since the heterogeneous transport calculation for such a large-scale problem requires large computer memory, a modular ray tracing in which all lattice cells have the same ray distribution for each direction was used to reduce the computer memory requirement. In this scheme, the ray tracing is performed only on different types of cells. Therefore, this ray tracing scheme can significantly reduce the time in tracing along neutron paths and the computer memory for storing track lengths. Also, a parallelization scheme in angular domain rather than in spatial domain and the coarse mesh/coarse group rebalance (CMR/CGR) method in inner and outer iterations were implemented for further reduction of the computer time. To show the effectiveness of the extended CRX code, it is applied to heterogeneous calculation of a benchmark problem core (i.e., 10 x 10 whole core). The results of the transport calculations by CRX are compared with those of TWODANT and with those of the diffusion nodal codes AFEN and NEM (nodal expansion method). Unless the usual homogenization based on single-assembly calculation is drastically improved, the nodal methods would have to be superseded by whole-core heterogeneous calculation methods. It would be feasible to perform whole-core heterogeneous transport calculations routinely if the MOC implemented in the CRX code is enhanced further by more effective acceleration schemes.
- Research Organization:
- Korea Advanced Institute of Science and Technology, Taejon (KR)
- Sponsoring Organization:
- none (US)
- OSTI ID:
- 786859
- Report Number(s):
- none; ISSN 0003-018X; CODEN TANSAO; ISSN 0003-018X; CODEN TANSAO
- Country of Publication:
- United States
- Language:
- English
Similar Records
Performance enhancement of planar MOC calculation in hexagonal geometries by assembly-wise domain decomposition
Unified Nodal Method Formulation for Analytic Function Expansion Nodal Method Solution to Two-Group Diffusion Equations in Rectangular Geometry
Performance Improvement of the Linear System Solver for CMFD Acceleration in PROTEUS-MOC
Conference
·
Fri Jul 01 00:00:00 EDT 2022
·
OSTI ID:23178715
Unified Nodal Method Formulation for Analytic Function Expansion Nodal Method Solution to Two-Group Diffusion Equations in Rectangular Geometry
Journal Article
·
Thu Feb 14 23:00:00 EST 2002
· Nuclear Science and Engineering
·
OSTI ID:20804761
Performance Improvement of the Linear System Solver for CMFD Acceleration in PROTEUS-MOC
Conference
·
Sun Jun 09 00:00:00 EDT 2019
·
OSTI ID:1528946