A helium leak detection method for stainless steel cladding of pools in the control area of ​​nuclear power units

Abstract

The invention relates to a helium leakage checking method used for a stainless steel cladding surface of a pool in a nuclear power unit control area. The pool includes a concrete base pool and a stainless steel plate group laid on the inner surface of the concrete base pool, the stainless steel plate group includes a plurality of stainless steel plates, each two adjacent stainless steel plates are connected by welding, the stainless steel plates and weld zones jointly form a stainless steel cladding surface on the inner surface of the concrete base pool, an approximately airtight accommodating space is formed between the stainless steel cladding surface and the concrete base pool, and the bottom of the concrete base pool is provided with a leading-out port connected to the accommodating space. The helium leakage checking method includes the steps of (1) using a helium filling device to be connected with the leading-out port to fill the accommodating space with helium; (2) verifying whether the accommodating space is filled with helium; and (3) performing helium leakage checking on the surfaces of the steel plates. After adoption of the abovementioned technical scheme, leak point checking can be conveniently performed on the stainless steel cladding surface of the pool before a nuclear power unit is on service.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing, in particular to a helium leak checking method for the stainless steel cladding of pools in the control area of ​​nuclear power units. Background technique [0002] Helium leak detection is widely used in nuclear power plants, petrochemicals, thermal power plants, steel plants, aviation and many other fields due to its high sensitivity, convenient use, and no impact on the environment. Helium leak detection is measured by the method of detecting the concentration of helium ions by a helium mass spectrometer. The helium mass spectrometer uses its main component, the mass spectrometer chamber, to turn helium of different masses into ions in a high-vacuum working environment, and the ions move in the electromagnetic field. deflection so that ions of different masses are separated from each other and ions of the same mass are brought together in the electromagnetic field. There is a ...

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Problems solved by technology

[0008] The invention provides a helium leak detection method suitable for the stainless steel cladding of the water pool in the control area of ​​the nuclear power unit, so as to overcome the inability of the stainless steel cladding in the control area of ​​the nuclear power unit to bear reverse pressure and the inability of the space between the stainless steel cladding and the concrete base pool in the prior art. When vacuuming and helium leak detection, there is a contradiction between the pressure difference on both sides of the inspected part, so as to realize the helium leak detection of the stainless steel cladding of the pool in the control area of ​​the nuclear power unit, detect the defects of the stainless steel cladding, ensure that the pool has no abnormal dripping, and ensure that the radioactivity is not exceeded vent

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