Method for accurately calculating space-time neutron distribution in nuclear reactor

Abstract

The invention discloses a method for accurately calculating space-time neutron distribution in a nuclear reactor. The method comprises the following steps of 1, directly solving a steady-state neutron transport equation by using a one-step method to obtain neutron flux density distribution and precursor concentration in a steady state; 2, solving a space-time neutron transport equation within 0.25ms, obtaining an amplitude value of 0.25ms through neutron flux density and a neutron flux density shape function at the moment of 0.25, and taking the amplitude value as an initial value of point reactor calculation; and 3, calculating the space-time neutron transport equation by using the one-step method in a large step length to obtain a predicted solution, solving a point reactor equation in an extremely small step length, and correcting the neutron flux density by using the amplitude value of a point reactor. By improving an existing prediction and correction quasi-static method, on the premise of not remarkably prolonging calculation time, rapid change of neutrons of the nuclear reactor in an extremely short time can be accurately captured, and the defects of the conventional prediction and correction quasi-static method are radically overcome, so that the method provided by the invention can play a real role in high-fidelity space-time neutron dynamics calculation.

Description

Technical field [0001] The invention relates to the technical field of nuclear reactor core design and nuclear safety, in particular to a method for accurately calculating the space-time electron distribution in a nuclear reactor. Background technique [0002] In the design of nuclear power plants, the design of nuclear reactors has always been at the core. In the design of nuclear reactors, it has always been a huge amount of neutron distribution to accurately simulate nuclear reactors at different points in time and at different positions during the transient process. challenge. At present, numerical simulation is the most important means of nuclear reactor design. Therefore, in order to accurately simulate the neutron distribution of nuclear reactors at different time points and different positions during the transient process, numerical simulation calculation methods are particularly important. [0003] In recent years, with the substantial increase in computer computing power...

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Problems solved by technology

[0006] In order to overcome the problems of the above-mentioned prior art and solve the problem of inaccurate calculation of the quasi-static method of estimation and correction under the situation of a sharp change in the power of the nuclear reactor, the purpose of the present invention is to propose a method for accurately calculating the distribution of electrons in space and time in the nuclear reactor, Based on the existing quasi-static method of prediction and correction, the method can accurately capture the rapid neutrons in a nuclear reactor in a very short time without significantly increasing the calculation time by improving the existing quasi-static method of prediction and correction. Changes, completely overcome the shortcomings of the traditional predictive correction quasi-static method, so that it can really play a role in high-fidelity spatiotemporal electron dynamics calculations

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