The pressuriser designated for the under-construction unit 5 of India’s Kudankulam nuclear power plant (KNPP) in Tamil Nadu has been shipped from Russia earlier this month, according to a statement by the Russian state atomic energy corporation Rosatom.
Rosatom is the equipment supplier and technical consultant for the KNPP, India’s largest nuclear plant operated by the state-run Nuclear Power Corporation of India Ltd. Its units 1 and 2 of 1,000 MW capacity each, started commercial operations in 2014 and 2016, respectively. Rosatom is similarly collaborating in the construction of four more VVER-1000 type units at Kudankulam – 3, 4, 5 and 6 – of 1,000 MW capacity each.
The pressuriser is a part of the primary circuit equipment of the VVER reactor and responsible for creating and maintaining pressure and coolant volume. It is used to limit pressure fluctuations in transient and emergency modes during the operation of a nuclear plant.
“The mass of the equipment is 187.5 tonnes. When assembled, it is about 14 meters long and 3.3 meters in diameter. Its capacity is 79 cubic meters, and the wall thickness is 152 millimeters,” a Rosatom statement said.
Rosatom’s machine building division Atomenergomash subsidiary AEM-Technologies shipped the pressuriser to Kudankulam on April 3, 2023, the statement added.
In January this year, AEM Technologies successfully tested the KNPP unit 5 pressuriser, which helps maintain the appropriate pressure of the coolant water used to transfer heat from fuel assemblies in the reactor pressure vessel to the steam generators. “The pressure in the tank was increased to the maximum allowable value for this equipment, which is 24.7 MPa (Megapascals),” a statement said.
The trial assembly of the internals of the reactor pressure vessel designated for unit 5 of KNPP was successfully undertaken also in January 2023 at the company’s Volgodonsk plant in Russia.
The reactor pressure vessel is the heart of a nuclear power plant. It contains the nuclear fuel assemblies which produce heat and forms part of the primary coolant circuit. It also contains provisions for sensors and moving parts such as control rods.
A control assembly, in which the products completely replicate their design position, significantly reduces the installation time and simplifies the process of installation of the reactor at the NPP construction site, a Rosatom statement had said.