Monitoring method for radiation embrittlement of reactor pressure vessel of nuclear power plant

A nuclear power plant reactor and pressure vessel technology, applied in the field of nuclear power, can solve problems such as long cycle time, high transportation cost, and large amount of three wastes to be treated

Active Publication Date: 2019-10-18
中广核工程有限公司 +1
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  • Application Information

AI Technical Summary

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

Method used

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  • Monitoring method for radiation embrittlement of reactor pressure vessel of nuclear power plant
  • Monitoring method for radiation embrittlement of reactor pressure vessel of nuclear power plant
  • Monitoring method for radiation embrittlement of reactor pressure vessel of nuclear power plant

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] Embodiment 1: upper platform energy-resistivity

[0048] Depend on figure 1 (b) It can be seen that:

[0049] ΔUSE / USE 0 =0.59-0.54exp(-2.74Δρ / ρ 0 ) (4.1)

[0050] Where: ΔUSE = USE 0 -USE; Δρ = ρ - ρ 0

[0051] Explanation: During the irradiation embrittlement process of RPV steel, the platform energy of the material decreases gradually, so here define ΔUSE=USE 0 -USE.

[0052] The unit of USE is Joule, and the unit of ρ is ×10 -7 ohm meter.

[0053] For this research object RPV steel, USE 0 is 335J, ρ 0 is 3.03×10 -7 Ω·m, USE=137.01+2803.03exp(-0.90ρ) after being substituted into the above formula for calculation.

Embodiment 2

[0054] Example 2: Reference temperature - initial magnetic susceptibility

[0055] Depend on figure 2 (d) know that:

[0056] ΔT 0 / T 00 =0.99-1.00exp(-4.27Δχ / χ 0 ) (4.2)

[0057] where: ΔT 0 =T 0 –T 00 ;Δχ=χ 0 -χ.

[0058] Explanation: The material reference temperature increases gradually during the irradiation embrittlement process of RPV steel, so ΔT is defined here 0 =T 0 –T 00 ; while the initial magnetic susceptibility is gradually reduced, so define Δχ=χ 0 -χ.

[0059] T 0 The unit of is absolute temperature, and χ is dimensionless.

[0060] For the RPV steel of this research object, T 00 is 203K, χ 0 is 11.406, after substituting into the above formula to calculate T 0 =404.97-2.84exp(0.37χ).

Embodiment 3

[0061] Example 3: Ductile-brittle transition temperature-saturation magnetization work

[0062] Depend on image 3 (c) know:

[0063] ΔRT NDT / RT NDT0 =0.94-0.89exp(-1.77ΔW / W 0 ) (4.3)

[0064] Where: ΔRT NDT =RT NDT -RT NDT0 ;ΔW=W-W 0 .

[0065] Explanation: During the irradiation embrittlement process of RPV steel, the ductile-brittle transition temperature of the material increases gradually, so here the definition of ΔRT NDT =RT NDT -RT NDT0 .

[0066] RT NDT The unit of is absolute temperature, and the unit of W is kilojoules / cubic meter.

[0067] For this research object RPV steel, RT NDT0 241K, W 0 246.3KJ / m 3 , after substituting into the above formula to calculate RT NDT =474.77-492.13exp(-0.0030W).

[0068] Table 4.1 Using the predictive unified model to characterize the fitting accuracy of the relationship model between the rate of change of mechanical properties and the rate of change of electromagnetic properties of reactor pressure vessel steel...

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Abstract

The invention discloses a monitoring method for radiation embrittlement of a reactor pressure vessel of a nuclear power plant. The monitoring method comprises the following steps: 1) acquiring an electromagnetic property parameter value X0 and a mechanical property parameter value Y0 of reactor pressure vessel steel at an initial state; 2) performing on-time testing on an electromagnetic propertyparameter X of a monitoring part of the reactor pressure vessel steel at one specific time point after radiation embrittlement; and 3) according to a function relation expression delta (Y)=A+B*exp[C*delta(X)], confirming a mechanical property parameter Y, wherein the electromagnetic property change rate delta (X)=IX-X0I/X0; the mechanical property change rate delta (Y)=IY-Y0I/Y0; and A, B and C are calculation coefficients. Compared with the prior art, the monitoring method for radiation embrittlement of the reactor pressure vessel of the nuclear power plant, which is disclosed by the invention, is not only capable of achieving real-time multi-time nondestructive measurement, but also precise in data, good in testing operation security, and capable of monitoring radiation embrittlement degrees of multiple positions of the reactor pressure vessel simultaneously.

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...

Claims

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Application Information

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IPC IPC(8): G21C17/003
CPCG21C17/003Y02E30/30
Inventor 李承亮束国刚刘伟谭珂赵建光段远刚
Owner 中广核工程有限公司
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