Multi-group section perturbation method for uncertainty analysis of reactor physics calculation

Abstract

The invention relates to a multi-group section perturbation method for uncertainty analysis of reactor physics calculation. The multi-group section perturbation method comprises the following steps: (1), on the basis of ENDF / B, making a multi-group section database and a point-by-point section database at different temperatures by using a nuclear database section processing program NJOY, and making the point-by-point section database in a resonant reaction channel at a resonant energy section into an ultra-fine-group database according to the equal rib width; (2), perturbing the point-by-point section database in the energy section corresponding to a certain energy group in a certain reaction channel so as to obtain a perturbed point-by-point section database; (3), strictly transferring perturbation of the point-by-point section database into the multi-group section database by using a linear and nonlinear perturbation transferring method; and (4), reconstructing by adopting a reaction channel section self-consistency principle to obtain a perturbed multi-group section database. According to the invention, the section of a basic reaction channel can be finely sampled; approximate treatment in the multi-group section perturbation process can also be reduced; and thus, a precise multi-group section sample can be obtained.

Description

technical field [0001] The invention relates to the technical field of reactor nuclear data evaluation and nuclear safety, and relates to a multi-group section perturbation method for uncertainty analysis of reactor physical calculation. Background technique [0002] The nuclear database is the most basic and critical input parameter for reactor physics calculations. Due to the unavoidable uncertainty in experimental measurements, it will introduce uncertainty into reactor physics calculations and directly affect the safety of reactors. In order to fully guarantee the safety of nuclear reactors, quantifying the uncertainty introduced by nuclear databases to the response of reactor physical calculations has become a hot spot and focus of international research. [0003] At present, the sampling method is widely used in the uncertainty analysis of reactor physics calculation due to its advantages of high precision and strong applicability, and quantifies the uncertainty introd...

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Problems solved by technology

[0004] There are two main problems in the existing multi-group section perturbation methods: first, only for the summation reaction channel involved in the calculation of neutron transport, for example, σ t ,σ a and σ s , but cannot consider the finer basic response channels, including σ (n,elas) ,σ (n,inel) ,σ (n,2n) ,σ (n,3n) ,σ (n,f) ,σ (n,γ) etc.; Second, a certain resonance approximation process is introduced to the multi-group section weight flux in the resonance energy section, and the multi-group resonance section samples obtained by sampling have certain accuracy problems

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