FCM (full ceramic microcapsulated) fuel effective multigroup cross section acquiring method

Abstract

Disclosed is an FCM fuel effective multigroup cross section acquiring method. The FCM fuel effective multigroup cross section acquiring method comprises, in a resonant energy section and based on a superfine group method, solving a TRISO (tristructure isotropic) particle and matrix material containing one-dimensional sphere model to obtain superfine group defect factors; through the superfine group defect factors, correcting the superfine group cross section of all nuclides to homogenize particles and matrix; through Dancoff factor equivalence, acquiring the equivalent one-dimensional rod model of every fuel rod of an FCM fuel, solving the superfine group slowing-down equation of the one-dimensional rod models to acquire the effective self-shielding cross section of the resonant energy section; in a heat energy section, through penetration probability and collision probability equivalence, acquiring multigroup defect factors, correcting the multigroup cross sections of all the nuclidesthrough the multigroup defect factors to homogenize fuel and matrix and to acquire the effective multigroup cross sections of the heat energy section. The FCM fuel effective multigroup cross sectionacquiring method can help effectively process the dual heterogenous effects of the FCM fuel to acquire a precise effective self-screening cross section.

Description

technical field [0001] The invention relates to the field of nuclear reactor core and nuclear reactor physical calculation, in particular to a method for obtaining the effective multi-group section of FCM fuel. Background technique [0002] After the Fukushima accident, the research on accident-tolerant fuels has become very urgent. FCM fuel is a kind of accident-tolerant fuel, and FCM fuel is also a kind of dispersed particle fuel. The fuel area is composed of matrix and TRISO fuel particles. There are double inhomogeneities in FCM fuel, namely the inhomogeneity of TRISO fuel particles in the fuel rod and the inhomogeneity of the fuel rod. Due to the double non-uniformity of FCM fuel, the traditional resonance calculation method cannot deal with this double non-uniformity. [0003] The first type of method to deal with double inhomogeneity is based on the transport theory of double inhomogeneous systems. This method can obtain more accurate multi-group effective cross-sec...

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Problems solved by technology

Due to the double inhomogeneity of FCM fuel, the traditional resonance calculation method cannot handle this double inhomogeneity

[0003] The first type of method to deal with double inhomogeneity is based on the transport theory of double inhomogeneous systems. This method can obtain more accurate multi-group effective cross-sections of FCM fuel, but the calculation efficiency is relatively low due to the need to solve the three-dimensional neutron moderation equation. Low

Another method is to use the self-screening calculation method of conventional fuels to calculate the self-screening section of particles, and then use the Dankov correction factor to correct the section, considering the influence of double non-uniformity on the self-screening section, this method cannot be used for particles and The matrix is ​​homogenized, and the volume weight is generally used to obtain the self-screen section directly, which will introduce calculation bias

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