Main Coolant Pipelines

One main coolant pipeline (MCP) set consists of 16 pipe spools made of 32 blanks (20 pipe blanks and 12 bends). The total length of the MCP set for one NPP power unit is 146 meters.

The length of the blanks varies from 4 000 to 8 500 mm, the diameter of the straight blank is 990 mm, the bend blanks are 1 130 mm in length, the wall thickness is 70 mm, the anticorrosive weld overlay thickness is 5 mm, the weight of the blank is up to 13 400 kg.

The MCP connects the main equipment of the NPP primary circuit: the reactor, steam generators, and reactor coolant pumps. It is designed for primary coolant circulation at temperatures up to 330 ℃ under high pressure of 160 atm. To protect the pipeline against coolant attack, the inner surface of forged blanks is covered with anticorrosive coating.