A Multiphysics Coupling Method in Transient Calculation of PWR

Abstract

The invention discloses a multi-physical coupling method in transient calculation of a pressurized water reactor. The method comprises the following steps of 1, for a multi-group space-time neutron kinetics equation, obtaining neutron-flux density and delayed-neutron precursor density of a prediction step by using a fully-implicit backward difference method; 2, obtaining a shape function of the prediction step through a normalization condition, linearly interpolating the shape function in a medium time step, and by solving an amplitude function equation on a small time step, finally obtaining neutron-flux density on the medium time step, thereby obtaining power and delayed-neutron precursor density; and 3, performing fuel temperature calculation and coolant temperature calculation through the power in the medium time step, realizing feedback through a nuclear reaction cross section, and realizing coupling with neutronics calculation. When the neutronics calculation is performed by using an improved quasi-static method of prediction and correction, heat engineering calculation and delayed-neutron precursor density calculation are performed on the proper time step to realize efficient coupling.

Description

technical field [0001] The invention relates to the field of nuclear reactor safety analysis and reactor physical calculation, in particular to a multi-physics coupling method in the transient calculation of a pressurized water reactor. Background technique [0002] In the traditional PWR safety analysis, it is necessary to analyze the parameters of the reactor (reactor power, core reactivity, etc.) , component power peak factor, etc.) is analyzed over time to see whether it meets the safety design requirements. Therefore, it is essential for the transient calculation of the reactor. In a steady-state PWR system, the introduction of disturbances will change the distribution of neutron flux density in the reactor, resulting in changes in reactor power. The power change of the reactor will directly lead to the change of the core temperature, and the temperature change will in turn affect the cross-section where the nuclear fuel and neutrons react in the reactor, thereby affe...

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Problems solved by technology

In a steady-state PWR system, the introduction of a disturbance will change the distribution of the neutron flux density in the reactor, resulting in a change in the reactor power

The power change of the reactor will directly lead to the change of the core temperature, and the temperature change will in turn affect the cross-section of the nuclear fuel and neutron reaction in the reactor, thereby affecting the distribution of the neutron flux density in the reactor

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