Reactor core power distribution monitoring method and system based on model order reduction and data assimilation

Abstract

The invention discloses a reactor core power distribution monitoring method and system based on model order reduction and data assimilation. The method comprises the following steps: acquiring reactor core operation state parameters in a current operation state; determining a local parameter domain of the current reactor core operation state parameters; determining discretization of a local parameter domain; calculating a physical field distribution set corresponding to a discrete parameter set by utilizing a reactor core physical calculation program and a parallel calculation architecture; performing dimension reduction on the physical field distribution set by adopting a model order reduction method to obtain a primary function; reading readings of detectors inside and outside the reactor core, and modeling a response function; carrying out primary function coefficient calculation; making the current physical field approximated as a linear combination of the primary function, the coefficient beingthe obtained primary function coefficient; and continuously updating the local parameter domain, and repeating the steps to realize on-line monitoring of the reactor core power distribution in the operation state of the reactor. According to the method, high-precision and high-speed online calculation is realized, and the influence of inaccurate background physical field solution on the power distribution reconstruction precision is eliminated.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor core operation and safety, in particular to a method and system for monitoring core power distribution based on model reduction and data assimilation. Background technique [0002] On-line monitoring of nuclear reactor core power distribution is of great significance to ensure the safety of the reactor core and improve the economic benefits of nuclear power plants. But the core power distribution is not a direct monitoring quantity, but the core power distribution is measured indirectly through the measurement of the neutron flux density. In order to measure the neutron flux density of the core in real time, neutron detectors are installed inside or outside the reactor, but these neutron detectors are only arranged at specific positions and the number is limited, so to achieve spatially continuous power distribution For real-time monitoring, it is very necessary to study the online reconf...

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Problems solved by technology

[0014] However, the methods described in these invention patents and published papers of the prior art all need to solve the neutron diffusion equation (or in a state close to the current core state) online (or offline). neutron transport equation), in order to obtain a spatially continuous power distribution (or neutron flux distribution); this not only produces a large amount of calculation, greatly increases the calculation time, but also in the online reconstruction calculation of the core power distribution Only the predicted value of power distribution (or neutron flux distribution) in one core state can be considered, and it is proposed that the core state corresponding to the neutron diffusion (or transport) calculation should be the same as the core state to be reconstructed. Consistent or close requirements, resulting in the deviation between the core power distribution (or neutron flux distribution) calculated by neutron diffusion (or transport) and the real power distribution (or neutron flux distribution) of the core directly determines the accuracy of the online reconstruction calculation of the core power distribution, therefore, this type of method does not have a wide range of stability

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