Monitoring method for irradiation embrittlement of reactor pressure vessel in nuclear power plant

Abstract

The invention discloses a method for monitoring radiation embrittlement of reactor pressure vessels of nuclear power plants, which comprises the following steps: 1) Obtaining the electromagnetic performance parameter value X of the initial state of reactor pressure vessel steel 0 and mechanical property parameter value Y 0 ; 2) Real-time testing to obtain the electromagnetic performance parameter X of the reactor pressure vessel steel monitoring position at a specific time point after radiation embrittlement; and 3) According to the functional relationship δ(Y)=A+B*exp[C* δ(X)] to determine the mechanical performance parameter Y, wherein, the rate of change of electromagnetic properties δ(X)=|X‑X 0 | / X 0 , rate of change of mechanical properties δ(Y)=|Y‑Y 0 | / Y 0 , A, B, C are calculation coefficients. Compared with the prior art, the method for monitoring radiation embrittlement of nuclear power plant reactor pressure vessels can not only realize real-time and multiple non-destructive measurements, but also have accurate data, good test operation safety, and can simultaneously monitor multiple positions of the reactor pressure vessel degree of radiation embrittlement.

Description

technical field [0001] The invention belongs to the technical field of nuclear power, and more specifically, the invention relates to a method for monitoring radiation embrittlement of a reactor pressure vessel of a nuclear power plant. Background technique [0002] Nuclear safety is the premise and the highest principle of nuclear power development, and the radiation embrittlement of reactor pressure vessels is an important part of nuclear safety. The reactor pressure vessel is one of the most critical equipment of the nuclear steam supply system of the nuclear power plant. It is the only large-scale equipment that cannot be replaced in the whole life of the nuclear power plant. Its safe service life determines the operating life and economy of the nuclear power plant. The main function of the reactor pressure vessel is to support the core fuel assembly, control assembly, reactor internals and the steel pressure vessel containing the primary circuit coolant. It is the secon...

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Problems solved by technology

[0009] (1) Since the mechanical properties of the reactor pressure vessel body cannot be obtained directly, it needs to be converted by the lead factor, so there is a certain error

When the leading factor is large, the amplification effect of the error becomes more obvious, and the representativeness of the obtained mechanical property changes will be poor

[0010] (2) Since the number of radiation supervision tubes is very limited (usually only 4-6, and must be installed at one time before the first loading operation, the existing technology cannot realize the supplementary installation of radiation supervision tubes after a period of operation ), and the number of irradiation supervision samples loaded in each irradiation supervision tube is also very limited, so continuous supervision and real-time supervision cannot be realized during the service period of the reactor pressure vessel. requirements

[0011] (3) After the radiation supervision tube is extracted from the reactor pressure vessel, it must be transported from the nuclear power plant to the designated hot cell organization. Since the radiation supervision tube has very high radioactivity, the security requirements during transportation are very high. High, the transportation cost is very high, and the cycle is long;

[0012] (4) 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 relatively large and costly;

[0013] (5) It can only monitor the degree of radiation embrittlement in the annular zone of the reactor pressure vessel (referring to the area with the most serious radiation embrittlement) as a whole, and does not have the ability to monitor other parts of the reactor pressure vessel, especially to track radiation embrittlement at specific locations. changes in degree of

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