Simplified two and three dimensional HTTR benchmark problems

Zhang, Zhan; Rahnema, Farzad; Zhang, Dingkang; Pounders, Justin M.; Ougouag, Abderrafi M.

doi:10.1016/j.anucene.2010.11.020

Cited by 22 publications

(7 citation statements)

References 4 publications

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“…Each coarse mesh is made of a uniform set of fine meshes, while different coarse meshes can have different size of fine meshes. [10]. Table provides the upper energies of the 6-group structure.…”

Section: Pentran Modelmentioning

confidence: 99%

“…The fuel type distribution in the 2D model is also shown in Table 3.2.3. A two and three dimensional numerical benchmark problems typical of high temperature gas cooled prismatic cores have been developed [10]. Additionally, we have included single cell and single block benchmark problems.…”

Section: Task 32 Generate 3d Benchmark Problemsmentioning

confidence: 99%

“…Initially the PENTRAN model was compared to the fuel assembly MCNP calculations from Zhang, et al [10]. This model did not include the corner regions that are not technically included in the fuel assembly, but are required for comparison with the PENTRAN model.…”

Section: Mcnp Modelmentioning

confidence: 99%

“…In this section we outline our efforts to model a 2D hexagonal fuel assembly from the Simplified 2D HTTR benchmark problem, Zhang et al [10], using the PENTRAN [11] 3-D Cartesian transport theory code system. To benchmark the PENTRAN model, we prepared a reference multi-group MCNP model.…”

Section: Generate 2d Benchmark Problemsmentioning

confidence: 99%

“…al. [10]. There are 3 different materials used in the model with cross-section information from the 26-group HELIOS library.…”

Section: Geometry and Model Specificationsmentioning

confidence: 99%

See 4 more Smart Citations

Consistent Multigroup Theory Enabling Accurate Course-Group Simulation of Gen IV Reactors

Rahnema¹,

Haghighat²,

Ougouag³

2013

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SUMMARYThe standard multi-group method used in whole-core reactor analysis relies on energy condensed (coarsegroup) cross sections generated from single lattice cell calculations, typically with specular reflective boundary conditions. Because these boundary conditions are an approximation and not representative of the core environment for that lattice, an error, known as core environment effect, is introduced in the core solution (both eigenvalue and flux). As current and next generation reactors trend toward increasing assembly and core heterogeneity, this error becomes more significant. Additionally, the angular dependence of the coarse-group total cross section for whole-core calculation is commonly ignored. The consistent energy condensation method corrects for both effects by generating updated coarse-group cross sections on-the-fly within whole-core reactor calculations without resorting to additional cell calculations and explicitly accounting for the angular dependence of the coarse-group total cross section. The core environment effect is fully corrected by making use of the recently published Generalized Energy Condensation Theory to unfold the fine-group core flux and recondense the cross sections at the whole-core level. By iteratively performing this recondensation, an improved core solution is found in which the core environment effect has been fully taken into account. Furthermore, the energy-angle coupling effect in the coarse-group calculation is accounted for by modifying the treatment of the total cross section to include orthogonal expansions in both energy and angle. As a result, the fine-group flux can be consistently reproduced during the coarse-group calculation. This recondensation method is both easy to implement and computationally very efficient because it requires pre-computation and storage of only the energy integrals and fine-group cross sections.Moreover, the consistent generalized energy condensation method was extended to subgroup decomposition method. The subgroup decomposition method enables the cross section condensation process by preserving spectral accuracy in condensed-group transport calculations in a simpler and more direct manner, without the need for the expansion in energy. The new "group decomposition" method directly couples a consistent coarse-group criticality calculation with a set of fixed-source "decomposition sweeps" to obtain the fine-group spectrum without the need to solve for higher energy moments of the flux.Also, the subgroup decomposition method which was developed in pure transport theory has been extended to pure diffusion and hybrid quasi transport/transport theories. The culmination of the works related to subgroup decomposition method confirms that the method is in fact an acceleration technique for solving fine-group eigenvalue transport (diffusion) problems. I. PROJECT OVERVIEW Project Objective:The objective of the project is the development of a consistent multi-group theory that accurately accounts for the energy-angle coupling associated w...

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Section: Pentran Modelmentioning

confidence: 99%

Section: Task 32 Generate 3d Benchmark Problemsmentioning

confidence: 99%

Section: Mcnp Modelmentioning

confidence: 99%

Section: Generate 2d Benchmark Problemsmentioning

confidence: 99%

“…al. [10]. There are 3 different materials used in the model with cross-section information from the 26-group HELIOS library.…”

Section: Geometry and Model Specificationsmentioning

confidence: 99%