Heavy water reactor nuclear power plant steam generator hand hole multifunctional foreign-matter-blockage preventive component

Abstract

The invention relates to the technical field of nuclear power plant running and maintaining, in particular to a heavy water reactor nuclear power plant steam generator hand hole multifunctional foreign-matter-blockage preventive component which comprises a plug, a sealing face protection cover plate, an operation handle and a rubber ring. The plug is of a cylindrical structure integrally, size ofthe plug is matched with that of a steam generator hand hole, multiple grooves are formed in the outer circumferential wall of the plug from top to bottom, and the rubber ring is embedded in the grooves in a compressed manner; a balance air pressure through hole penetrating the plug and three threaded blind holes uniformly distributed around the balance air pressure through hole are formed in themiddle of a sealing face of the upper portion of the plug, an internal thread is formed in the balance air pressure through hole and used for being matched with an operation handle thread for penetrating operation. The component has functions of plugging a hand hole, resisting foreign matters and protecting a hand hole sealing face and is simple in structure, convenient to mount, reliable in operation, light in weight, convenient for carrying and transporting and capable of avoiding risks like foreign matter inhalation and sealing face scratching during maintenance operation.

Description

technical field [0001] The invention relates to the technical field of operation and maintenance of nuclear power plants, in particular to a multifunctional anti-foreign matter blocking assembly for a hand hole of a steam generator in a heavy water reactor nuclear power plant. Background technique [0002] The steam generator is the key equipment of the primary circuit of the heavy water reactor nuclear power plant. It is the main pressure boundary between the primary and secondary circuits of the nuclear power plant. The regular preventive maintenance of the steam generator is carried out to ensure the integrity, safety and reliability of the steam generator structure. It is of great significance to the safe, stable and economical operation of nuclear power plants. [0003] There are 4 steam generators in each unit of heavy water reactor nuclear power plant, and there are 3 hand holes above the tube sheet of each steam generator. These handholes are used as the only access...

AI Technical Summary

Problems solved by technology

[0006] 1. The installation of the plug is unreliable, and it may fall into the steam generator as a foreign object

[0007] 2. There is a gap between the plug and the inner wall of the hand hole. When the plug is pulled out, metal debris may enter the steam generator.

[0008] 3. Due to changes in the liquid level and pressure of the secondary side of the steam generator during the plugging process, negative pressure may be formed inside the steam generator, and the plug may be difficult to pull out or be sucked into the steam generator

[0009] 4. The sealing surface of the hand hole is protected by adhesive tape, the protection form is unreliable, and the sealing surface is damaged by tools during the maintenance process

[0010] 5. The plug is pasted with tape. The halogen elements in the tape material may remain around the hand hole, causing corrosion of the sealing surface

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