Govt shuts unit at largest Tamil Nadu nuclear power plant for maintenance

The Central Electricity Authority, India's power advisory body, said the 1,000 MW Unit 1 at Kudankulam in Tamil Nadu was shut on August 3

India has shut a unit at its Kudankulam nuclear reactor, the largest in the country, for scheduled maintenance last week, according to an outage report, possibly spiking power prices for southern regions.

The 1,000 megawatt (MW) Unit 1 at Kudankulam in the southern state of Tamil Nadu was shut on August 3, the Central Electricity Authority, the country's power advisory body, said in a report dated August 7.

Confirming that one unit of Kudankulam is under maintenance, a senior official with Tamil Nadu Distribution and Generation Company said the state might have to tap market sources if the need for additional demand arises.

The official from the state government did not want to be identified as India's nuclear facilities are controlled by the federal government.

Earlier, the Kerala State Electricity Board Ltd (KSEBL) filed a petition with the state's electricity regulator, saying the shutdown is expected to worsen the peak-hour electricity shortages in some southern states, driving up short-term power procurement costs.

The 65-day outage, coupled with low volumes on power exchanges and increased demand from neighbouring states, had forced it to procure 300 MW of peak-hour power at rates as high as 9.18 rupees ($0.1048) per unit of electricity.

The utility finalised purchases from Tata Power at 8.75 rupees per unit and Greenko Energies at 9.18 rupees per unit for the slot between 07:00 PM IST and 00:00 AM IST slot throughout August, the petition showed.

"The projected peak-hour deficit of around 600 MW in August 2025 may worsen due to the scheduled refuelling outage of the Kudankulam nuclear power plant," KSEBL said.

Kerala's electricity regulator approved the emergency procurement but flagged concerns over the high tariffs.

The other 1,000 MW unit 2 at Kudankulam is operating normally, according to the Tamil Nadu government official.

India aims to expand nuclear capacity to at least 100 gigawatt by 2047, up from about 9 gigawatt currently.