Russia's Rosatom, the technical consultant and main equipment supplier for India's largest nuclear power plant at Kudankulam near Kanyakumari, has installed an advanced safety feature 'core melt catcher' or 'core melt localisation device (CMLD)', at the bottom of the upcoming Unit-3 power plant's protective shell to increase the safety of the reactor.
Uniquely designed by Russian nuclear experts and an important safety system for modern nuclear reactors, the core catcher is designed to localise and cool the molten core material in case of an accident and confine it within the protective shell of the reactor to prevent radioactive emissions into the external environment. Core catcher, a next generation safety device, has improved seismic resistance, hydro-dynamic and shock strength, as well as flood protection and simplified installation and assembly technology. Weighing 147.5 tonnes, it was lifted to the height of 27 meters and installed in the design position by using a tracked crane placed between two nuclear islands, said a Rosatom official.
The new system gains significance as recently the Indian government had confirmed detecting a malware attack in September at the administrative software systems of the state-run Nuclear Power Corporation of India Ltd's (NPCIL) Kudankulam Nuclear Power Plant (KKNPP). The Kudankulam power plant, based on light water nuclear technology, is being constructed as part of a Russia-India agreement in 1988. The first 1000 megawatt (MW) unit was commissioned in October 2013 and the second 1000 MW unit was commissioned in August 2016. Currently Unit-3 and Unit-4 are under construction and the equipment supplier Rosatom has shipped in all the critical equipment of these units.
"This is a special system for beyond-design-basis accidents management," said Vladimir Angelov, Director for Projects in India at ASE, the engineering division of Rosatom State Atomic Energy Corporation.
The core catcher, one of the elements of the passive safety systems, was first installed at China's Tianwan Nuclear Power Plant of Russian design. The main feature of the Kudankulam NPP project is its unique combination of active and passive safety systems that provides maximum resistance against external and internal influences. The passive safety systems are capable of functioning even in the event of a complete loss of power supply. They can provide full safety without the active systems and an operator.
The NPCIL runs 22 commercial nuclear power reactors with an installed capacity of 6,780 megawatts (MW).