Method and device for monitoring irradiation damage of reactor pressure vessel in nuclear power plant

Abstract

The invention discloses a method and a device for monitoring irradiation damage of a reactor pressure vessel in a nuclear power plant. The method comprises the following steps of calculating the change rate of resistivity after reactor pressure vessel steel is subjected to the irradiation damage by measuring initial resistivity of the reactor pressure vessel steel and acquiring the resistivity of the reactor pressure vessel steel after the irradiation damage at any time point in real time; obtaining change conditions of macro-mechanical property parameters of the reactor pressure vessel steel in the irradiation damage according to the change rate of the resistivity after the irradiation damage; further analyzing and evaluating the irradiation damage degree of the reactor pressure vessel according to the macro-mechanical property parameters. The method and the device are economical, environment-friendly, safe and efficient; the irradiation damage degree of a plurality of parts (including specific parts) of the reactor pressure vessel can be monitored 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 for real-time monitoring of radiation damage of reactor pressure vessels of nuclear power plants. Background technique [0002] The reactor pressure vessel of a nuclear power plant is a closed container used to accommodate a nuclear reactor and withstand its huge operating pressure, which contains and supports the core nuclear fuel assembly, control assembly, reactor internals and reactor coolant. Due to its long-term service in strong irradiation, high temperature, and high pressure environments, it is prone to neutron radiation damage, which is specifically manifested in the increase in strength and decrease in toughness during the irradiation embrittlement of reactor pressure vessel steel, which further leads to the failure of reactor pressure vessel. [0003] At present, the reactor pressure vessel steels of my country...

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Problems solved by technology

[0005] (1) Limited by the internal space of the reactor pressure vessel, the number of radiation monitoring tubes that can be loaded is very limited, and it is impossible to monitor multiple parts (including specific parts) of the reactor pressure vessel, and the above radiation monitoring tubes must be tested for the first time. The one-time loading is completed before the loading operation, and the radiation supervision tube cannot be installed during the operation, which cannot fully meet the radiation supervision requirements of the reactor pressure vessel when the life extension of the nuclear power plant in the future;

[0006] (2) After the radiation supervisory tube is extracted from the reactor pressure vessel, it must be transported from the nuclear power plant to a designated hot cell institution. At present, only two units in Sichuan and Beijing have this hot cell. The inspection and supervision tube has very high and strong radioactivity, so the security requirements during transportation are very high, the transportation cost is high, and the cycle is long;

[0007] (3) Since the mechanical performance test of the irradiation supervision sample is a destructive test, a large amount of radioactive waste will be generated after the test is completed, and the subsequent treatment of the three wastes will be large and costly;

[0008] (4) Since the irradiation supervision samples come from the rest of forgings in the core area, the above method can only monitor the damage degree of the reactor pressure vessel core area as a whole, but cannot monitor other parts of the reactor pressure vessel. Especially the degree of radiation damage at a specific location

[0009] (5) The above method does not have the ability to monitor the radiation damage of reactor pressure vessel steel, and can only obtain the radiation damage degree of reactor pressure vessel steel at certain specific time points (depending on the extraction time of the radiation supervision tube)

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