Device for carrying out ultrasonic automatic inspection on pipe fittings penetrating through top cover of pressure vessel

Abstract

The invention relates to a nondestructive security detection technology for reactor pressure vessels, and particularly discloses a device for carrying out ultrasonic automatic inspection on pipe fittings penetrating through a top cover of a pressure vessel. A lifting cylinder drives a frame and a lifting mechanism in the frame to carry out synchronous lifting, so the lifting mechanism is driven to drive a lifting shaft and a rotating shaft to lift together, and a rotating motor drives the rotating shaft to rotate, so that a probe can accurately and smoothly enter a penetrating piece so as to realize the automatic inspection on the penetrating piece; in the process of operating, an elastic sealing ring is bent downward and adhered to the inner wall of a bell mouth of the penetrating piece to carry out static water-shutoff, so that less water in the penetrating piece leaks downward; a water container is designed, so that water leaked from the bell mouth is collected in the water container and discharged from a water discharge nozzle; an elastic rubber ring is designed, so that when an upper laminated plate is contacted with the bell mouth, a certain elastic buffer can be obtained so as to avoid impacting the penetrating piece; and by using a O-shaped sealing ring, an upper water-shutoff felt, a middle water-shutoff felt and a lower water-shutoff felt, and through appropriate extrusion and dynamic sealing, the hermetic installation among parts can be ensured.

Description

technical field [0001] The invention belongs to the non-destructive safety detection technology of reactor pressure vessels, and in particular relates to an ultrasonic automatic inspection device for penetrating pipe fittings. Background technique [0002] The top cover of the reactor pressure vessel of a nuclear power plant is a hemisphere with an inner diameter of SR890mm and a wall thickness of 157mm, with the top facing upwards, like a pot with its mouth facing downwards. Many pipe fittings are installed on the top cover, referred to as penetration parts, with an inner diameter of Φ70mm and a wall thickness of 17.5mm. The lower part is welded with the inner wall of the top cover through a J-shaped weld to form the pressure boundary of the main system of the primary circuit of the nuclear island. The lower end is equipped with Install a horn-shaped guiding device, referred to as the horn mouth. The interior of the top cover penetration accommodates the control rods that ...

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Problems solved by technology

[0005] At present, only large testing companies in the world, such as Framatome of France, can implement automatic ultrasonic inspection of the J-shaped weld of the reactor pressure vessel top cover penetration, but the operation of the equipment is difficult, and the price is very high, so it cannot be directly inspected. Applied to the automatic ultrasonic inspection of roof penetrations of the same type and different specifications in my country, the adaptability is poor, and it is difficult to meet the requirements of my country's nuclear power plants for this inspection

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