High-fidelity full-core resonance calculation method based on coupling of global local coupling method and subgroup method

Abstract

The invention discloses a high-fidelity full-core resonance calculation method based on coupling of a global local coupling method and a subgroup method, and the method comprises the steps: dividing all resonance material regions into a fuel lattice cell resonance region and other resonance regions, and employing a high-precision global local coupling resonance method for the fuel lattice cell resonance region, then marking the material areas subjected to resonance calculation; solving other resonance material areas by adopting a subgroup method, and only carrying out full-pile subgroup fixed source calculation on strong absorber resonance nuclides or structural body resonance nuclides; and only other resonance areas are subjected to background iteration (bindarenko iteration) to calculate an effective self-shielding cross section. And after the resonance calculation is finished, all the resonance material areas are re-marked as non-resonance calculation areas, so that the next resonance calculation is facilitated. The method combines the advantages of a global local coupling resonance method and a subgroup method, solves the problem that the global local coupling method cannot perform resonance calculation on a large strong absorber, and has higher precision and calculation efficiency compared with the subgroup method.

Description

Technical Field

[0001] The present invention relates to the technical fields of nuclear reactor core design and safety, and particularly to a high-fidelity full-core resonance calculation method based on the coupling of global-local coupling method and subgroup method. Background Art

[0002] The key parameter for high-fidelity numerical simulation analysis of reactors is to obtain multi-group effective self-shielding cross-sections, which are mainly obtained through resonance calculations. Although a large number of resonance calculation methods have been studied at home and abroad, for complex geometric reactor types, traditional resonance calculation methods are still difficult to apply. In complex geometric reactor types, the geometric forms of fuel and strong absorbers are diverse. Although the simple global-local coupling method can efficiently calculate the self-shielding cross-sections of fuel lattice cells, it is difficult to effectively calculate large-sized absorbers or structural materials with a large number of resonances. And although the simple subgroup method has good geometric adaptability and can solve resonance regions of any geometry, on the one hand, it is necessary to pre-make non-uniform resonance integral tables, and on the other hand, its accuracy and efficiency are inferior to those of the global-local coupling method. Therefore, for complex geometric reactor types, a resonance calculation method that can handle any geometric type and meet certain accuracy and efficiency requirements is needed. Summary of the Invention

[0003] In order to overcome the problems existing in the above-mentioned existing resonance methods, the purpose of the present invention is to provide a high-fidelity full-core resonance calculation method based on the coupling of global-local coupling method and subgroup method. This method has better geometric adaptability than the global-local coupling method and can handle complex or large-sized strong absorbers or structural materials; compared with the traditional subgroup method, it has higher accuracy and faster calculation efficiency.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A high-fidelity full-core resonance calculation method based on the coupling of global-local coupling method and subgroup method includes the following steps:

[0006] Step 1: Read the geometric information and material information of the core containing large-sized absorbers;

[0007] Step 2: Divide the resonance regions based on the geometric information and material information, and divide all resonance regions into fuel lattice cell resonance regions and other resonance regions;

[0008] Step 3: For the fuel lattice cell resonance regions, use the global-local coupling resonance method to calculate, obtain the effective self-shielding cross-sections of the fuel and cladding in the fuel lattice cells, and mark the resonance material regions in the fuel lattice cells as having undergone resonance calculations;

[0009] Step 4: For other resonance regions, the subgroup method is used for resonance calculation. In the subgroup calculation, only the subgroup fixed source equations are solved for the resonance nuclides of strong absorbers or the resonance nuclides of structural materials, and there is no need to solve the fixed source equations for the fuel resonance nuclides, which can improve the calculation efficiency;

[0010] Step 5: Perform background iteration calculation of the subgroup method on other resonance regions to obtain the effective self-shielding cross sections of the resonance nuclides of strong absorbers or the resonance nuclides of structural materials in other resonance regions;

[0011] Step 6: After the global-local coupled resonance calculation and the subgroup resonance calculation are completed, all resonance material regions are relabeled as unresonated calculation regions to facilitate the next resonance calculation.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] The present invention is a coupling method based on the global-local method and the subgroup method, integrating the advantages of both methods. First, compared with the global-local coupling method, the present invention solves the problem that it is difficult to perform resonance calculation for a resonance calculation involving large-sized absorbers. The present invention can perform resonance calculation for large-sized absorbers. Second, compared with the subgroup method, the present invention has higher calculation accuracy and efficiency when calculating problems involving large-sized absorbers. Brief Description of the Drawings

[0014] Figure 1 is a flow chart of the method of the present invention.

[0015] Figure 2 is a schematic diagram of an example in the specific implementation manner.

[0016] Figure 3 is a top view schematic diagram of a standard fuel assembly, a control rod assembly, and an irradiation assembly. Specific Embodiment

[0017] The present invention will be further described in detail below with reference to the drawings and specific examples.

[0018] The present invention is a high-fidelity full-core resonance calculation method based on the coupling of the global-local coupling method and the subgroup method. Taking the three-dimensional full-core problem of the JRR3M research reactor as an example, as Figure 1 shown, the specific steps are as follows:

[0019] Step 1: Read the material and geometric information of the three-dimensional full core of the JRR3M research reactor. As Figure 2 shown, JRR3M is a three-dimensional full-core problem containing 37 components, and the large-sized cruciform control rods are all inserted into the core. There are three types of components in the core, namely standard fuel assemblies, control rod assemblies, and irradiation assemblies, as Figure 3 shown. The control rod assembly is composed of large-sized cruciform hafnium (Hf), and the periphery is an aluminum square tube.

[0020] Step 2: According to the geometric material information obtained in Step 1, divide all resonance regions. Divide the fuel lattice cells in the standard fuel assembly into fuel lattice cell resonance regions, and divide the large-sized square hafnium in the control rod assembly into other resonance regions.

[0021] Step 3: For all fuel lattice cell resonance regions, adopt the global-local coupled resonance method. This method has high precision and fast speed, and can accurately calculate the effective self-shielding cross-sections of the fuel and the cladding. And after the calculation, mark the resonance material regions in the fuel lattice cells as having undergone resonance calculations.

[0022] Step 4: Adopt the subgroup method to perform resonance calculations for other resonance regions. And in the subgroup calculation, only solve the subgroup fixed-source equation for hafnium and its isotopic resonance nuclides, without solving the fixed-source equation for fuel resonance nuclides, which can reduce the number of times of solving the subgroup fixed-source equation and improve the calculation efficiency.

[0023] Step 5: Perform background iteration calculations using the subgroup method on other resonance regions to obtain the effective self-shielding cross-sections of hafnium and its isotopic resonance nuclides in this material region.

[0024] Step 6: After the global-local coupled resonance calculation and the subgroup resonance calculation are completed, re-mark all resonance material regions as un-resonated calculation regions for the next resonance calculation. The calculation results are shown in Table 1;

[0025] Table 1

[0026]

[0027] It can be seen from the calculation results in Table 1 that the present invention is 63 pcm higher than the subgroup method in terms of precision and about 53.96% higher in terms of resonance calculation efficiency.

Claims

1. A high-fidelity full-core resonance calculation method based on the coupling of the global-local coupling method and the subgroup method, characterized in that Divide the resonance region and calculate by region, including the following steps: Step 1: Read the geometric information and material information of the core with large-sized absorbers; Step 2: Based on the geometric information and material information, divide the resonance region, and divide all resonance regions into fuel assembly resonance regions and other resonance regions; Step 3: For the fuel assembly resonance region, use the global-local coupled resonance method to calculate, obtain the effective self-shielding cross-sections of the fuel and cladding in the fuel assembly, and mark the resonance material regions in the fuel assembly as having undergone resonance calculations; Step 4: Use the subgroup method to perform resonance calculations for other resonance regions. In the subgroup calculation, only solve the subgroup fixed-source equation for strong absorber resonance nuclides or structural material resonance nuclides, and there is no need to solve the fixed-source equation for fuel resonance nuclides to improve the calculation efficiency; Step 5: Perform background iteration calculations using the subgroup method on other resonance regions to obtain the effective self-shielding cross-sections of strong absorber resonance nuclides or structural material resonance nuclides in other resonance regions; Step 6: After the global-local coupled resonance calculation and subgroup resonance calculation are completed, re-mark all resonance material regions as un-resonance calculated regions to facilitate the next resonance calculation.

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