Radioactive environment large-scale shield main pump integral dismantling device and dismantling process

Abstract

The invention provides a radioactive environment large-scale shield main pump integral dismantling device and dismantling process and belongs to the technical field of nuclear power station large-scale shield main pump maintenance. The radioactive environment large-scale shield main pump integral dismantling device comprises a main bolt pneumatic disassembling and assembling tool, an upper C-typering internal residual liquid draining tool, an upper C-type ring cutting tool, a pump case shielding protective tool and an impeller shielding and rotor locking tool. The radioactive environment large-scale shield main pump integral dismantling device is easy to operate and capable of safely and efficiently completing dismantling of a large-scale shield main pump.

Description

technical field [0001] The invention relates to the technical field of maintenance of a large-scale shielded main pump of a nuclear power plant, in particular to an integral disassembly device and a disassembly process of a large-scale shielded main pump in a radioactive environment. Background technique [0002] After a long period of operation of the nuclear power plant, the shielded reactor coolant pump (hereinafter referred to as: the shielded main pump) may have problems with the thrust bearing, the shielding sleeve, and the lower locking cup. Plan and develop the shielded main pump in a radioactive environment in advance. It is necessary to disassemble the pump as a whole. The pump casing of the shielded main pump is welded to the bottom head of the steam generator, and installed upside down on the pump casing through 24 main bolts. The space around the shielded main pump is compact and narrow, and the position of the shielded main pump cannot be reached by hoisting. ...

AI Technical Summary

Problems solved by technology

[0008] The impeller shielding and locking rotor device of the shielded main pump needs to be developed: the shielded main pump is installed upside down at the bottom of the evaporator. When the damaged shielded main pump is disassembled from the pump casing, the hydraulic parts such as the pump impeller are directly exposed to the environment, and the environmental dose is very high. , will seriously affect the subsequent maintenance work of the shielded main pump such as hoisting, overturning and transfer; in addition, in the process of hoisting, overturning and transportation of the shielded main pump, in order to prevent the rotor from moving and damage the thrust bearing components and other components, it is necessary to lock the main pump before turning over. Tightly shield the main pump rotor assembly; therefore, effective shielding of the pump impeller portion and locking of the rotor assembly must be performed

Through the comprehensive analysis of the site working conditions, the structure of the canned main pump and the overall disassembly process of the canned main pump, the restrictive factors in the prior art are as follows: (1) The space of the canned main pump chamber is limited, and it needs to be completed when the pump is dropped and moved to hoisting Locking of the rotor assembly of the shielded main pump and installation of the impeller shielding device after opening; (2) The hoisting passage of the shielded main pump is narrow, so the rotor locking device, the impeller shield and the main spreader need to be integrated and installed, and the rotor is locked After the installation of the device and impeller shielding cover is completed, the installation of the main spreader shall not be interfered with, and the overall dimensions of the rotor locking device and the impeller shielding cover shall not exceed the external dimensions of the main spreader; (3) The impeller of the shielded main pump is directly connected to the primary circuit , high radioactive environmental dose; (4) There is residual radioactive medium at the impeller of the shielded main pump, and there is a risk of leakage

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