Welding of the main coolant pipeline has commenced at Kudankulam NPP Unit 3

30.12.2022

Welding of the main coolant pipeline (MCP) has commenced at Kudankulam NPP Unit 3 (Republic of India, general designer and general contractor is Rosatom State Corporation Engineering Division).

This stage continues construction of the power unit after installation of the reactor pressure vessel (April 2022) and dome closing (November 2022). MCP welding is a complex process operation which covers 16 pipe units and includes several stages: preparation, welding-up, heat treatment, non-destructive testing, austentic surfacing, performed by the highly-qualified personnel. The total MCP length is about 140 m, pipe wall thickness is 70 mm, the total length of 28 welded
joints is over 87 m.

“What is remarkable about Unit 3 is that the customer, responsible for installation of thermal and mechanical equipment, took the best practices of Russian companies as a basis for the MCP welding. This will allow reducing the period of MCP welding from the scheduled 255 days to 120-150 days with all the requirements for safety and quality fulfilled consistently”, noted Andrey Lebedev, ASE JSC Vice President for Projects in India. “We are interested in high-quality and dynamic cooperation with our Indian partners and grateful to them for the trust and openness which affect the development of our common project in a positive way”,

MCP is a part of the primary coolant circuit along with the reactor and four circulation loops, each of which, in its turn, includes the steam generator, reactor coolant pump set and main coolant pipelines connecting the loop equipment with the reactor and steam generator. The design service life of MCP in tough environment (pressure 160 atm., temperature 3500С) is 60 years.

Timely completion of MCP welding in conjunction with the installation of thermal and mechanical equipment determines the commencement of flushing to the open reactor and the stage of hydraulic tests and circulation flushing of the primary circuit.

Information about Kudankulam NPP Project

Power units No 3,4 and 5,6 are the second and the third stages of Kudankulam NPP constructed under AES-92 design with VVER-1000 (V-412) reactor type. The technical solutions implemented in Kudankulam design characterize further evolutionary development of VVER-reactor NPPs of high power and transition to creation of a new, reliable, safe and feasible power unit.

New power units of Kudankulam NPP comply with the most up-to-date safety requirements of IAEA.

The developer (the technical customer of the facility) is Nuclear Power Corporation of India. The general designer and supplier of equipment is ASE JSC.

Currently, power units No. 1, 2 of Kudandulam NPP are operating at the capacity established by the operation schedule.

Russia is consistently developing international trade and economic relations, focusing on cooperation with friendly countries. Despite external restrictions, the domestic economy is growing its export potential and supplies goods, services and raw materials all over the world.