Unit 1 at India's Kakrapar nuclear power plant, a 220MW PHWR, achieved first criticality on 19 May after completing modernisation and refurbishment works three months ahead of schedule.

Kakrapar 1, located in Gujarat, is operated by Nuclear Power Corporation of India Ltd (NPCIL) and has been in service since in 1993. The unit was taken offline in 2016 for the refurbishment project.

Work involved coolant channel replacement, feeder replacement and other safety upgrades. "The task, which was scheduled to be completed in August 2019, was completed ahead of schedule by over three months," NPCIL said in a statement.

Repair and maintenance of Kakrapar 2 was also completed three and a half months ahead of schedule in September 2018, it added.

Two 700MW indigenous PHWRs are at an advanced stage of construction at Kakrapar 3&4, and expected for completion in 2019 and 2020.