The first 1,000 MW unit in Kudankulam Nuclear Power Project (KNPP) belonging to Nuclear Power Corporation of India Ltd (NPCIL) was shut down for around two months for refuelling purposes on Thursday, said a senior official.

Kudankulam is in Tirunelveli district around 650 km from here and NPCIL has two 1,000 MW nuclear power plants there built with Russian equipments.

"The first unit was shut down at 3.38 a.m. on Thursday for refuelling purposes. The shut down will be for around 70 days," HN Sahu, Site Director, KNPP told IANS over phone on Friday.

Every year, one third of the reactor's 163 fuel assemblies -- 54 assemblies -- will be replaced.

This coming refuelling cycle will be the second for Unit 1.

According to Sahu, the second unit at KNPP is generating power at full capacity.

Meanwhile, the first 220 MW unit of Madras Atomic Power Station (MAPS) belonging to NPCIL under annual maintenance shutdown is expected to come into operation from April 27 onwards.