Chennai, May 20 (IANS): The first 220 MW nuclear power plant at Kakrapar Atomic Power Station (KAPS-1) will be synchronised with the grid next week and power generation will be increased after that, a senior official of Nuclear Power Corporation of India Ltd (NPCIL) said.

The KAPS-1 unit/reactor attained criticality, or initiation of controlled self sustaining nuclear fission chain reaction, on Sunday, following the replacement of the entire coolant channel, feeder replacement and safety upgrades.

The replacement of coolant channel and feeder were necessitated after the reactor shut down automatically on March 11, 2016 following leakage of heavy water from its coolant channel. The leak was plugged ten days later.

"After the 2016 shutdown, the reactor attained criticality only on May 19. The KAPS-1 will be synchronised with the grid on 23/24 of this month. Then the power levels will be increased," the official told IANS on the condition of anonymity.

India's atomic power plant operator NPCIL has two 220 MW units pressurised heavy water reactor (PHWR) at KAPS. Following the heavy water leak, unit 1 was under cold shut down.

Similarly, the renovation and modernisation of KAPS-2 was completed in 2018 and is operating at full capacity, the official added.