A weighted Monte Carlo calculation method for neutron dynamics

Abstract

The invention discloses a weighted Monte Carlo calculation method for neutron kinetics. The method comprises the following steps that: 1: establishing an initial particle source library, simulating initial particles, if the initial particles are neutrons, jumping to 2, and if the initial particles are delayed neutron precursors, jumping to 4; 2: sampling time for the neutrons to generate nuclear reaction, if the time exceeds transient process time t, jumping to 5, and otherwise, jumping to 3; 3: sampling to determine a type for the neutron to generate the nuclear reaction, if scattering reaction happens, keeping particle weight to constant, jumping to 2, if adsorption reaction happens, changing the weight of a descendant particle, sampling to determine the existence state of the descendant particle, if the descendant particle is the neutron, jumping to 2, and if the descendant particle is the precursor, jumping to 4; 4: sampling precursor decay time, if the time exceeds the transient process time, jumping to 5, otherwise, changing a particle state into the neutron, and jumping to 3; and 5: carrying out statistics on the contribution of the particle, if particles which are not simulated are still in the presence in the source library, jumping to 1, and otherwise, ending to output a result.

Description

technical field [0001] The invention relates to the fields of nuclear reactor design and reactor physics calculation, in particular to a weighted Monte Carlo calculation method of neutron dynamics. Background technique [0002] The Monte Carlo method is a method widely used in reactor physical analysis and calculation. In systems described by steady-state neutron transport equations, that is, systems in which physical quantities do not change with time, the solution obtained by this method is usually regarded as a reference solution. Compared with the deterministic method, the Monte Carlo method has its unique advantages in the determination of errors, the increase in the amount of calculation for multidimensional problems, and the accuracy. [0003] The application of the Monte Carlo method in the solution of the steady-state neutron transport equation specifically includes solving the power distribution, iteratively solving the k eff And give the cross-sectional data of ...

AI Technical Summary

Problems solved by technology

Although the Monte Carlo method has accumulated a lot of experience in steady state analysis and has many improved methods, in the analysis of neutron dynamics, the Monte Carlo method is still limited to the traditional direct simulation method

This method takes a lot of time, takes up a lot of memory, and the variance of the model is large, so there is still a lot of room for improvement in the accuracy of the results.

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