Method and device for evaluating neutron irradiation damage of reactor pressure vessel of nuclear power station

Abstract

The invention discloses a method and a device for evaluating neutron irradiation damage of a reactor pressure vessel of a nuclear power station. Reactor pressure vessel steel neutron irradiation damage fluence is calculated by measuring initial resistivity of reactor pressure vessel steel and acquiring resistivity of the reactor pressure vessel steel at any time point in real time after neutron irradiation damage; the irradiation damage degree of the reactor pressure vessel is analyzed and evaluated according to the reactor pressure vessel steel neutron irradiation damage fluence. The method and the device are economical, environmentally friendly, safe, efficient and capable of monitoring irradiation damage degrees of multiple parts and specific parts of the reactor pressure vessel in real time.

Description

technical field [0001] The invention relates to the field of safe operation of reactor pressure vessels of nuclear power plants, in particular to a method and device for evaluating neutron radiation damage of reactor pressure vessels of nuclear power plants. Background technique [0002] The reactor pressure vessel is one of the most critical large-scale equipment in the nuclear island of a nuclear power plant. Its main function is to contain and support the steel pressure vessel of the core nuclear fuel assembly, control assembly, reactor internals and reactor coolant. It has served in strong radiation, high temperature and high pressure environment for a long time. Among them, neutron radiation damage (specifically manifested as an increase in strength and a decrease in toughness during the irradiation embrittlement of reactor pressure vessel steel) is one of the main failure modes. [0003] In order to ensure the safety of reactor pressure vessel operation, monitoring an...

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Problems solved by technology

[0005] (1) Fission dose detector (U 238 and Np 237 ) is a radioactive source, and its production, transportation, and sales all require professional qualifications. At present, my country cannot produce it, and only Belgium can supply civil nuclear power to my country abroad. The procurement cost is very high, and subsequent transportation and compliance are also extremely troublesome;

[0006] (2) The radiation damage fluence of the reactor pressure vessel body cannot be directly obtained, and it needs to be converted by the lead factor, and there is a certain error. When the lead factor is large, the error becomes more obvious, and the neutron radiation damage fluence obtained at that time are less representative;

[0007] (3) Due to the very limited number of radiation supervision tubes, usually only 4 to 6, and they must be loaded at one time before the first loading operation, and the existing technology cannot realize the supplementary installation of radiation supervision after a period of operation In spite of this, this problem will become more prominent when the life of nuclear power plants is extended in the future, and the number of corresponding fission dose detectors is only 4 to 6, so the neutron radiation damage fluence of reactor pressure vessel steel cannot be continuously obtained by this method; It takes at least one year for supervisors to extract, transport, cut and dissect, and test and analyze fission dose detectors. Therefore, there is an obvious time lag in obtaining the neutron radiation damage fluence of reactor pressure vessel steel by this method.

[0008] (4) The fission dose detector is a one-time product and has strong radioactivity after use. At the same time, a large amount of radioactive waste is also generated in the analysis and testing process. The subsequent treatment of three wastes is relatively large and the cost is high;

[0009] (5) The above method can only monitor the neutron radiation damage fluence in the core area of ​​the reactor pressure vessel as a whole, and does not have the ability to monitor the radiation damage fluence of other parts of the reactor pressure vessel, especially the radiation damage in a specific position

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