Whole-Core Heterogeneous Transport Calculations and Their Comparison with Diffusion Results
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usual homogenization based on single-assembly calculation is drastically improved, the nodal methods would have to be superseded by whole-core heterogeneous calculation methods.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):
- ISSN 0003-018X; CODEN TANSAO; ISSN 0003-018X; CODEN TANSAO; TRN: US0109356
- Resource Relation:
- Conference: 2000 International Conference on Nuclear Science and Technology: Supporting Sustainable Development Worldwide (2000 ANS Winter Meeting), Washington, DC (US), 11/12/2000--11/16/2000; Other Information: Transactions of the American Nuclear Society, Volume 83; PBD: 12 Nov 2000
- Country of Publication:
- United States
- Language:
- English
Similar Records
Implementation of CMFD Acceleration Scheme in PROTEUS-MOC
A Validation Study of Existing Neutronics Tools against ZPPR-21 and ZPPR-15 Critical Experiments
Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
CALCULATION METHODS
DIFFUSION
HETEROGENEOUS REACTOR CORES
RADIATION TRANSPORT
MIXED OXIDE FUELS
COMPUTER CODES
COMPARATIVE EVALUATIONS
TRANSPORT THEORY
C CODES
PARALLEL PROCESSING
BENCHMARKS