Method for obtaining resonance group constant by aiming at dual heterogeneous fuel of nuclear reactor

Abstract

The invention discloses a method for obtaining a resonance group constant by aiming at the dual heterogeneous fuel of a nuclear reactor. On the basis of an ultrafine group resonance calculation method, an energy spectrum obtained by solving a neutron slowing-down equation by a lattice cell of which the fuel region is homogenized and a point section corrected by a Shmakov method on the basis of a dual heterogeneous geometrical parameter are subjected to merging on the basis of volume flux weight to obtain the resonance group constant. Compared with a non-deterministic theory Monte Carlo method, the method disclosed by the invention can obviously improve calculation efficiency and economic efficiency. Meanwhile, the coupling of two methods enables a deterministic theory ultrafine group resonance calculation method to own a capability of processing a complex dual heterogeneous geometric resonance problem, the application of the ultrafine group resonance calculation method can accurately process a resonance interference effect which is in the presence in fuel and can obtain accurate homogenized resonance group constant.

Description

technical field [0001] The invention relates to the nuclear reactor core and the field of nuclear reactor physical calculations, in particular to a method for obtaining resonance group constants for nuclear reactor double heterogeneous fuels. Background technique [0002] Traditional pressurized water reactors use rod-shaped geometric fuel, and the development of traditional resonance calculation methods is also based on this type of fuel to calculate and provide resonance group constants, which provide section coefficients for solving transport equations. With the advent of double non-homogeneous fuel in nuclear reactors, the geometry is more irregular, which poses a challenge to traditional resonance calculation methods. [0003] Double Heterogeneity (DH) fuel realizes that the fuel pellets in the PWR cell are replaced by a matrix randomly dispersed with TRISO (Tri‐structural Isotropic) fuel particles, and the silicon carbide (SiC) shell of TRISO particles The structure r...

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Problems solved by technology

figure 2 It is a schematic diagram of the geometry of the dual heterogeneous fuel of the existing nuclear reactor, and a schematic diagram of the structure of the existing TRISO particles loaded in the dual heterogeneous fuel for reference image 3 , it can be seen from the figure that the geometric structure of dual non-uniformity fuel is more complex than that of traditional PWR fuel. Traditional resonance calculation methods are divided into two categories: strict solution of moderation equation and resonance integral table. The effective description of the influence of the random arrangement of fuel particles on the multi-group self-screening section, coupled with the insufficient description ability for the double inhomogeneity geometry, makes it impossible to directly calculate the resonance group constant of the double inhomogeneity fuel

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