Validation of the U.S. NRC NGNP evaluation model with the HTTR
- Dept. of Nuclear Engineering, Univ. of Michigan (United States)
The High Temperature Test Reactor (HTTR) was modeled with TRITON/PARCS. Traditional light water reactor (LWR) homogenization methods rely on the short mean free paths of neutrons in LWR. In gas-cooled, graphite-moderated reactors like the HTTR neutrons have much longer mean free paths and penetrate further into neighboring assemblies than in LWRs. Because of this, conventional lattice calculations with a single assembly may not be valid. In addition to difficulties caused by the longer mean free paths, the HTTR presents unique axial and radial heterogeneities that require additional modifications to the single assembly homogenization method. To handle these challenges, the homogenization domain is decreased while the computational domain is increased. Instead of homogenizing a single hexagonal fuel assembly, the assembly is split into six triangles on the radial plane and five blocks axially in order to account for the placement of burnable poisons. Furthermore, the radial domain is increased beyond a single fuel assembly to account for spectrum effects from neighboring fuel, reflector, and control rod assemblies. A series of five two-dimensional cases, each closer to the full core, were calculated to evaluate the effectiveness of the homogenization method and cross-sections. (authors)
- Research Organization:
- American Nuclear Society, Inc., 555 N. Kensington Avenue, La Grange Park, Illinois 60526 (United States)
- OSTI ID:
- 22105903
- Resource Relation:
- Conference: PHYSOR 2012: Conference on Advances in Reactor Physics - Linking Research, Industry, and Education, Knoxville, TN (United States), 15-20 Apr 2012; Other Information: Country of input: France; 9 refs.
- Country of Publication:
- United States
- Language:
- English
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BURNABLE POISONS
CONTROL ELEMENTS
CROSS SECTIONS
EVALUATION
FUEL ASSEMBLIES
GCR TYPE REACTORS
GRAPHITE
HOMOGENIZATION METHODS
HTTR REACTOR
MEAN FREE PATH
NEUTRONS
NUCLEAR FUELS
SPECTRA
TWO-DIMENSIONAL CALCULATIONS
VALIDATION
WATER COOLED REACTORS
WATER MODERATED REACTORS