SIMULATE-3 Pin Power Reconstruction: Methodology and Benchmarking

Rempe, K.R.; Smith, Kord; Henry, A.

doi:10.13182/nse89-a23686

Cited by 88 publications

(24 citation statements)

References 1 publication

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“…High-enrichment UO 2 Low-enrichment UO 2 Fig. 4 Specification of the high-and low-enrichment UO 2 assembly Since the presence of the control blade has an impact on the calculation accuracy, it is also included in the evaluation.…”

Section: Heterogeneous Homogeneousmentioning

confidence: 99%

“…If such heterogeneous fuel assemblies from the viewpoint of neutronics properties are loaded, the prediction of pin power would be more difficult, since the current advanced nodal method homogenizes the fuel assembly and utilizes pin-power reconstruction. 2) Furthermore, since the performance of affordable computers is greatly improved, more complex calculation methods can be carried out in practical computational time. Therefore, the development of more accurate core calculation methods for BWR is desirable.…”

Section: Introductionmentioning

confidence: 99%

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Applicability of the Diffusion and Simplified P3 Theories for Pin-by-Pin Geometry of BWR

Tada

Yamamoto

Yamane

et al. 2008

J. Nucl. Sci. Technol.

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The pin-by-pin fine-mesh core calculation method is considered as a candidate next-generation core calculation method for BWR. In this study, the diffusion and simplified P3 (SP3) theories are applied to the BWR pin-by-pin fine-mesh calculation. The performances of the diffusion and SP3 theories for cell-homogeneous pin-by-pin fine-mesh calculation for BWR are evaluated through comparison with a cell-heterogeneous detailed transport calculation by the method of characteristics (MOC). Two-dimensional, 2 Â 2 multi-assemblies geometry is used to compare the prediction accuracies of the diffusion and SP3 theories. The 2 Â 2 multi-assemblies geometry consists of 9 Â 9 UO 2 fuel assemblies that have two different enrichment splittings. To minimize the cell-homogenization error, the SPH method is applied for the pin-by-pin fine-mesh calculation. The SPH method is a technique that reproduces a result of heterogeneous calculation using that of homogeneous calculation. The calculation results indicated that the diffusion theory shows a discrepancy larger than that of the SP3 theory on the pin-wise fission rate distribution. In contrast to the diffusion theory, the SP3 theory shows a much better accuracy on the pin-wise fission rate distribution. The computation time using the SP3 theory is about 1.5 times longer than that using the diffusion theory. The BWR core analysis consists of various calculations, e.g., the cross section interpolation, neutron flux calculation, thermal hydraulic calculation, and burn-up calculation. The function of the calculation time for the neutron flux calculation is usually less than half in the typical BWR core analysis. Therefore, the difference in the calculation time between the diffusion and SP3 theories would have no significant impact on the calculation time of the BWR core analysis. For these reasons, the SP3 theory is more suitable than the diffusion theory and is expected to have sufficient accuracy for the 2 Â 2 multi-assemblies geometry used in this study, which simulates a typical situation of the actual BWR core.

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Section: Heterogeneous Homogeneousmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Applicability of the Diffusion and Simplified P3 Theories for Pin-by-Pin Geometry of BWR

Tada

Yamamoto

Yamane

et al. 2008

J. Nucl. Sci. Technol.

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“…In the conventional boiling water reactor (BWR) core analysis with lattice physics and core calculations, assembly-homogenized coarse-group (one to three group(s)) cross sections are obtained by spatial average and energetic collapse of heterogeneous fine-group (dozens to a few hundred groups) cross sections [1,2]. These spatial homogenization and energy collapsing are performed through lattice physics calculations in single assembly geometries with the reflective boundary condition.…”

Section: Introductionmentioning

confidence: 99%

“…In the present study, Equation (35) is used for all reaction types of cross sections (i.e., absorption, fission, production cross sections, scattering matrices, and diffusion coefficients) since they are collapsed with neutron fluxes as Equation (1). The applicability of Equation (35), which is derived from Equation (31), is verified through numerical calculations in Section 3.…”

mentioning

confidence: 98%

A new technique for spectral interference correction on pin-by-pin BWR core analysis

Fujita

Endo

Yamamoto

2014

Journal of Nuclear Science and Technology

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A new correction technique to capture the spectral interference effect on collapsed cross sections, which focuses on application to the pin-by-pin boiling water reactor (BWR) core analysis, is proposed. The spectral interference effect, which is caused by adjacent loadings of different types of fuel assemblies, has relationship with variations of neutron leakage in each pin-cell from the viewpoint of neutron balance. Variation of neutron leakage affects neutron spectrum and thus the neutron leakage is considered to be important to correct coarse-group cross sections used in core calculations. We focus on the neutron leakage in each pin-cell and use it as a correction index (i.e., a leakage index (LI)), which is defined as the volume-averaged neutron leakage in a pin-cell. By utilizing the leakage index, we represent the variations of coarse-group cross sections as the linear combination of LIs. In order to verify and discuss the applicability of the present correction technique, two-dimensional benchmark calculations considering typical characteristics of BWR cores are carried out. From the calculation results, the present correction technique well reproduces the reference coarse-group cross sections and improves the calculation accuracies.

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“…Heterogeneous cross sections are homogenized within a fuel assembly and the number of energy groups is reduced to a few numbers. Finally, a core calculation is carried out with a few energy groups using the assembly homogenized cross sections obtained in the previous step [1,2]. In general, the energy group structures used in the above calculations have been empirically determined.…”

Section: Introductionmentioning

confidence: 99%

An optimization approach to establish an appropriate energy group structure for BWR pin-by-pin core analysis

Fujita

Tada

Endo

et al. 2012

Journal of Nuclear Science and Technology

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An optimization approach to establish an appropriate multi-group energy structure for boiling water reactor (BWR) pin-by-pin fine mesh core analysis is proposed. In the present approach, the number of energy groups of cross sections is successively reduced or increased. In order to select an energy group boundary that is removed or added, performances of all possible candidates of energy group structures are tested in multi-assembly geometries. Then, the energy group boundary, which provides the minimum difference of the k-infinity or the pin-by-pin fission rate distribution, is finally removed or added. This procedure is repeated until the number of energy groups reaches to the target value. In order to confirm the applicability of the present approach, the accuracies of the k-infinity and the pin-by-pin fission rate distribution are investigated in various 2 6 2 multi-assembly geometries with the established energy group structure. From the verification results, the differences of the k-infinity and the pin-by-pin fission rate distribution between the reference (fine) and the established (coarse) energy group structure are small in the various 2 6 2 multiassembly geometries. Therefore, we can conclude that the present approach is efficient to establish an appropriate energy group structure for BWR pin-by-pin fine mesh core analysis.

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SIMULATE-3 Pin Power Reconstruction: Methodology and Benchmarking

Cited by 88 publications

References 1 publication

Applicability of the Diffusion and Simplified P3 Theories for Pin-by-Pin Geometry of BWR

Applicability of the Diffusion and Simplified P3 Theories for Pin-by-Pin Geometry of BWR

A new technique for spectral interference correction on pin-by-pin BWR core analysis

An optimization approach to establish an appropriate energy group structure for BWR pin-by-pin core analysis

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