Cold mounting process for pressurized water reactor nuclear power plant voltage stabilizer penetration pieces

The invention belongs to a process of pressurized water reactor nuclear power plant equipment and particularly relates to a cold mounting process for pressurized water reactor nuclear power plant voltage stabilizer penetration pieces. The cold mounting process comprises the steps of (1) opening pores for mounting penetration pieces in a casing according to the design size, and processing location bosses on the outer side of the casing; (2) processing the outer diameters of the penetration pieces matched with the pores according to the actual pore diameters on the casing and the required interference magnitude and processing location bosses simultaneously; (3) submerging the penetration pieces in liquid nitrogen to be cooled; (4) taking the penetration pieces out to be inserted in the corresponding pores in the casing rapidly; (5) when the penetration pieces and the casing temperatures rise to the room temperature, space between the penetration pieces and the pores of the penetration pieces on the casing is eliminated, that is, interference fit between the penetration pieces and the casing pores is achieved. The cold mounting process has the advantages that uniform deformation of the voltage stabilizer penetration pieces and the voltage stabilizer casing pores can be guaranteed, and accordingly, the stress between the penetration pieces and the casing pores is uniform, and the risk of failure of the positions during the operation of the power plant is reduced.