Method for calculating yield of multi-group slow luminophores by using fission yield and decay data

Abstract

The invention discloses a method for calculating a multi-group slow luminescence photon yield by using a fission yield and decay data. The method comprises the following steps: firstly, calculating a multi-group decay photon yield of each nuclide based on a decay photon energy spectrum given in a decay sub-library of an evaluation nuclear database; constructing decay information of each nuclide according to the decay mode and the branching ratio data; secondly, fission yield data under different neutron incident energies are selected according to different requirements; then constructing decay chain information of all fission products until each fission product decays to a stable nuclide; according to fission yield data, adding decay photons generated in the process of decaying fission products to stable nuclides in different energy ranges, so as to obtain the multi-group slow luminescence photon yield of the fission nuclides; and finally, in order to ensure the accuracy of heat release calculation of the slow luminophores, correcting the yield of the multi-group slow luminophores obtained by calculation by using the average fission slow luminophore energy given in the evaluation kernel database. The method is high in calculation precision and calculation efficiency.

Description

technical field [0001] The invention relates to the fields of calculation of heat release and radiation shielding of nuclear reactors, in particular to a method for calculating the yield of multi-group slow photons by using fission yield and decay data. Background technique [0002] In the calculation of the heat release of a nuclear reactor, the effects of neutrons and photons on the heat release calculation need to be considered at the same time. In the calculation of photon heat release, not only the contribution of transient photons such as capture reaction, fission reaction and inelastic scattering reaction to the photon source term should be considered, but also the photons generated by the fission products of fission nuclides during the decay process to the photon source. The photons produced by the fission products of fission nuclides during the decay process are called slow photons. [0003] In order to consider the contribution of slow photons in the photon transp...

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Problems solved by technology

[0004] However, only a small amount of fissile nuclides in the evaluation nuclear database currently provide MT460 reaction channel data. Taking the ENDF / B-VII.1 evaluation nuclear database as an example, there are only 235 U and 239 Pu gave the slow photon source function, which cannot calculate the slow photon data of other fission nuclides, which leads to certain limitations in the above method, and cannot perform slow photon data of all fission nuclides based on the slow photon source function processing method. deal with

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