Cell homogenization methods for pin-by-pin core calculations tested in slab geometry

Yamamoto, Akio; Kitamura, Yasunori; Yamane, Yoshihiro

doi:10.1016/j.anucene.2003.12.001

“…To overcome this problem, an assumption that DF SPH is constant throughout the assembly surface is introduced in the improved SPH method. Then the discontinuity factor is defined for each cell and can be incorporated by dividing all (SPH-corrected) cross-sections in the assembly [9]. Thus the inverse of DF SPH can be regarded as an additional SPH factor in the simultaneously SPH-corrected P N equation.…”

Section: Resultsmentioning

confidence: 99%

“…Number of energy group is one and uniform fixed source over the configuration, whose intensity is 1.0 (1/cm 3 /s), is assumed. This assumption captures the situation in thermal energy groups of light water reactor assembly calculation [9]. Cross-sections used in these calculations are shown in Table 1.…”

Section: Calculation Configurations and Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

A note on application of superhomogénéisation factors to integro-differential neutron transport equations

Chiba

¹

,

Tsuji

²

,

Sugiyama

³

et al. 2012

Journal of Nuclear Science and Technology

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The present article focuses on the application of the SPH factor method to the integro-differential neutron transport equation. While leakage-related parameters are arbitrarily corrected by the SPH factors, the correction procedure for these parameters affects the calculation accuracy. We treat two correction procedures named the simultaneous correction and the direct correction, and compare them with each other in one-dimensional colorset assembly problems. Through numerical testing, we find that the simultaneous SPH correction gives better accuracy than the direct SPH correction, and the higherorder SPH-corrected calculations show better accuracy than the low-order ones. Furthermore, to consider the flux discontinuity between different types of assemblies, the improved SPH method proposed by Yamamoto and the SPH method with the Selengut normalization condition are also tested. Numerical results reveal that the both methods significantly improve the calculation accuracy and that the latter method is more robust than the former method.

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“…6) The calculation results revealed that homogenization error (error in pin-by-pin absorption rate) of the SPH method were larger than that of GET, especially at interface region between different assembly types.…”

Section: Introductionmentioning

confidence: 88%

Improvement of the SPH Method for Pin-by-Pin Core Calculations

Yamamoto

¹

,

Tatsumi²,

Kitamura

³

et al. 2004

Journal of Nuclear Science and Technology

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In this paper, improvement of the SPH method (the improved SPH method) is proposed. The SPH method is commonly used in pin-by-pin mesh core calculations to reduce cell-homogenization error. The investigation revealed that the normalization condition of the SPH factor in the conventional SPH method is not appropriate for multi-assembly calculations in which different assembly types are adjacent. Since the conventional normalization condition does not incorporate flux discontinuity between assemblies, cell homogenization error in assembly peripheral region becomes larger. In the improved SPH method, the SPH factor is divided by an averaged ''cell-level'' discontinuity factor obtained in each fuel assembly. Though the SPH factor is somewhat modified from the conventional value, no additional homogenization parameters (e.g. discontinuity factor) is necessary in core calculations. Test calculations were carried out in a simplified one-dimensional slab and two-dimensional PWR colorset geometries that simulate part of actual core geometry. The calculation results showed that the improved SPH method effectively reduce the cell-level homogenization error especially in assembly peripheral region. Since we can easily implement the improved SPH method by slight code modifications, it can be a promising candidate of the cell-homogenization method for pin-by-pin core calculations.

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“…Some of the authors compared cell-homogenization capability of the SPH and GET methods in the simplified pin-bypin geometry that simulates PWR colorset configurations. 6) The calculation results revealed that homogenization error (error in pin-by-pin absorption rate) of the SPH method were larger than that of GET, especially at interface region between different assembly types.…”

Section: Introductionmentioning

confidence: 88%

Improvement of the SPH Method for Pin-by-Pin Core Calculations

Yamamoto

¹

,

Tatsumi²,

Kitamura

³

et al. 2004

J. Nucl. Sci. Technol.

Self Cite

0

View full text Add to dashboard Cite

In this paper, improvement of the SPH method (the improved SPH method) is proposed. The SPH method is commonly used in pin-by-pin mesh core calculations to reduce cell-homogenization error. The investigation revealed that the normalization condition of the SPH factor in the conventional SPH method is not appropriate for multi-assembly calculations in which different assembly types are adjacent. Since the conventional normalization condition does not incorporate flux discontinuity between assemblies, cell homogenization error in assembly peripheral region becomes larger. In the improved SPH method, the SPH factor is divided by an averaged ''cell-level'' discontinuity factor obtained in each fuel assembly. Though the SPH factor is somewhat modified from the conventional value, no additional homogenization parameters (e.g. discontinuity factor) is necessary in core calculations. Test calculations were carried out in a simplified one-dimensional slab and two-dimensional PWR colorset geometries that simulate part of actual core geometry. The calculation results showed that the improved SPH method effectively reduce the cell-level homogenization error especially in assembly peripheral region. Since we can easily implement the improved SPH method by slight code modifications, it can be a promising candidate of the cell-homogenization method for pin-by-pin core calculations.

show abstract

Cell homogenization methods for pin-by-pin core calculations tested in slab geometry

Cited by 18 publications

References 9 publications

A note on application of superhomogénéisation factors to integro-differential neutron transport equations

A note on application of superhomogénéisation factors to integro-differential neutron transport equations

Improvement of the SPH Method for Pin-by-Pin Core Calculations

Improvement of the SPH Method for Pin-by-Pin Core Calculations

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