A Method for Obtaining Sensitivity Coefficients of Important Parameters Calculated by Reactor Physical Grid

Abstract

The invention provides a method for acquiring a sensitivity coefficient of an important parameter of reactor physical grid computation. The method comprises: 1, establishing a computing model for a specific reactor physical computing problem; 2, adopting a subgroup resonance self-shielding method to perform resonance self-shielding computation, establishing a corresponding generalized conjugate equation for a fast group source term, a resonance energy group source term and a resonance self-shielding section, and solving the generalized conjugate equation to obtain a sensitivity coefficient of a resonance self-shielding section; 3, for an important parameter that needs to be computed, establishing and solving the generalized conjugate equation corresponding to the important parameter, so as to obtain an explicit sensitivity coefficient of the parameter; and 4, combining the sensitivity coefficient of the resonance self-shielding section and the explicit sensitivity coefficient of the resonance self-shielding section to obtain an implicit sensitivity coefficient, wherein a total sensitivity coefficient is equal to the sum of the explicit sensitivity coefficient and the implicit sensitivity coefficient. According to the method provided by the invention, the sensitivity coefficient of any parameter that can be represented as a flux or conjugate flux functional can be obtained quickly; an implicit effect is also considered; and thus the sensitivity coefficient is more accurate.

Description

technical field [0001] The invention relates to the field of nuclear reactor core design and safety, in particular to a method for obtaining a reactor physical grid to calculate the sensitivity coefficient of important parameters. Background technique [0002] Conventional nuclear reactor design and operation often use conservative calculations, or set a large enough safety margin to ensure the safety of the reactor. Although this approach can ensure the safety of the reactor to a certain extent, it loses great economics. In recent years, there has been an increasing international demand for "best estimates + uncertainties" of nuclear reactor safety parameters in the fields of nuclear research, nuclear industry, nuclear safety and nuclear regulation. [0003] In the sensitivity and uncertainty analysis of nuclear data in the calculation of the reactor physical grid, the calculation of the sensitivity coefficient is an important link to obtain the uncertainty of the calculat...

AI Technical Summary

Problems solved by technology

However, in many current sensitivity and uncertainty analysis procedures, the implicit sensitivity as an indirect effect is often ignored, and only the explicit sensitivity as a direct effect is considered, which will inevitably introduce certain errors

In addition, the current implicit sensitivity analysis is often based on the relatively simple resonance self-screening method, but the implicit sensitivity analysis for the current mainstream resonance calculation method - the subgroup method is not extensive and in-depth

On the other hand, the sensitivity and uncertainty of effective value-added factors are widely valued, but the analysis and calculation of other important parameters (such as minority group constants, power distribution, etc.) are not sufficient

Images