A Composite Correction Method for the History Effect of the Minor Group Constant of a Pressurized Water Reactor

Abstract

The invention relates to a composite correcting method for the pressurized water reactor few group constant history effect. The composite correcting method includes the following steps that 1, in a reactor core, a predictor-corrector method is used for burn-up calculation to obtain atomic nucleus density of each nuclide in true history; 2, the few group microscopic cross section is corrected based on difference of atomic nucleus densities of four important nuclides 233U, 235U, 239Pu and 241Pu under typical working conditions and actual operation history; 3, the history effect of the few group macroscopic cross section is compositely corrected by combining correction of the atomic nucleus densities and correction of the few group microscopic cross section; 4, an accurate calculation result can be obtained by transmitting the obtained few group macroscopic cross section sigmate actual under the actual operation history to a three-dimensional reactor core calculation procedure. On one hand, the atomic nucleus density of each nuclide in the reactor core is calculated in real time to eliminate deviation of the atomic nucleus density; on the other hand, the difference of atomic nucleus densities of four important nuclides 233U, 235U, 239Pu and 241Pu is used for reflecting difference of energy spectrum history and then eliminating deviation of the few group microscopic cross section.

Description

technical field [0001] The invention relates to the fields of nuclear reactor design and reactor physical calculation, in particular to a compound correction method for the historical effect of the minority group constant of a pressurized water reactor. Background technique [0002] In the traditional two-step method of PWR core physical calculation, the few group parameters required for core calculation are provided by component programs. Because the state parameters in the core (fuel temperature, moderator temperature, boron concentration, control rod position, etc.) change very complicatedly, the average value of the state parameters in the core is generally selected as the typical working condition value. Under typical working conditions, the components are subjected to a series of burnup calculations or branch calculations, and the obtained minority group parameters are stored in the interface program by means of tabulation or fitting for core calculation. Since the bu...

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Problems solved by technology

Nuclides that are more affected by power are often nuclides with shorter half-lives. At the moment of power change, the nuclear density of these nuclides will have a large change, which will bring a large deviation to the calculation results of the infinite proliferation factor.

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