Method for specially processing decay heat calculation in compression process of fuel consumption database

Abstract

The invention relates to a method for specially processing decay heat calculation in a compression process of a fuel consumption database, which comprises the following steps of: calculating a representative nuclear fuel assembly by using a fine fuel consumption database to obtain a set of related data, and restarting fuel consumption calculation under the condition of assuming that a fission product does not react with neutrons to obtain another set of data; and using two sets of data for carrying out decay heat calculation twice, firstly, selecting a few of heavy nuclides with great contribution of heavy nuclear decay heat, secondly, selecting important contribution nuclides of the fission product irradiation effect, adding a few of heavy nuclides with great contribution and the important contribution nuclides of the fission product irradiation effect into the compressed fuel consumption database, and deducting the fission product irradiation effect from decay heat, so as to obtain afission system decay heat release function, further obtaining a fission sub-system decay heat release function based on the fission product decay hypothesis, finally performing twice nonlinear fitting on the fission sub-system decay heat release function to obtain multiple groups of decay heat precursor kernels, and adding the multiple groups of decay heat precursor kernels into the compressed fuel consumption database. The decay heat result calculated by the method is more accurate.

Description

technical field [0001] The invention relates to the fields of nuclear reactor core design and nuclear reactor physical calculation, and relates to a special processing method for decay heat calculation during the compression process of a burnup database. Background technique [0002] The burnup problem is an important part of reactor physics analysis, which focuses on the interconversion relationship and energy release of nuclides in the core through decay or seed reaction. The starting point of modeling the burnup problem is the burnup database specifying the nuclides and the transformation properties between nuclides, referred to as the burnup chain. The burnup chain defined in the nuclear evaluation database (such as ENDF / B-VII.0) is very complex, including thousands of nuclides and their interconversion relationships. In most practical calculations of reactor physics, there is no need to use such a fine burnup chain, but a compressed burnup chain is used to save computi...

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Problems solved by technology

[0005] In order to solve the above-mentioned existing problems, the purpose of the present invention is to provide a method for special processing of decay heat calculation in the process of compressing the burnup database, which divides the decay heat calculation into a few heavy nuclei decays and a few fission product decays and Limited decay heat precursor nuclei, and the decay heat precursor nuclei are added to the compressed burnup database in the form of pseudo-fission products, and conventional fission products are replaced in the decay heat calculation, so as to solve the problem that the compressed burnup database cannot Problems used for decay heat calculations

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