Rescue workers searched Russia's largest hydroelectric plant today for 64 missing workers after an accident during repairs killed at least 12 others at the massive plant in southern Siberia.
The cause of yesterday's accident at the Sayano-Shushenskaya plant was unclear. Federal investigators said a transformer exploded during repair works, destroying walls and the ceiling in an engine room where turbines are located and causing the room to flood.
The plant's owner said the flooding occurred due to a pressure surge in water pipes.
Twelve workers were confirmed dead and 64 were missing, Russian Emergency Situations Minister Sergei Shoigu told the Itar-Tass news agency.
Some of the dead had drowned and others were crushed by debris, Ministry spokesman Roman Dotsov told The Associated Press, adding that 14 survivors were hospitalised with a range of injuries, including concussions and exposure.
Rescue workers combed through the cavernous engine room today, trying to find the missing workers.
The accident shut down the power station, which supplies several major aluminum plants. The government said electricity supplies from other power plants were being rerouted to help cover the shortfall, but outages were reported throughout the region.
The plant's dam, a towering structure that stretches about a kilometre across the Yenisei River, was not damaged and towns downstream were in no danger, Shoigu said.
The accident produced an oil spill, however, and a slick as large as 25 square kilometres was floating downriver, the Natural Resources Ministry said.
Two of the plant's 10 turbines were destroyed and a third was seriously damaged, said Vasily Zubakin, acting chief executive of the plant's owner, RusHydro. He said the company was still assessing the state of the remaining seven turbines.
Shoigu said the repairs would be difficult.
"We're probably talking about years rather than months to restore three of the 10 turbines," he said on state-run television.
The world's largest aluminum producer, Rusal, was operating as usual, with its smelters being powered from other plants, company spokeswoman Yelena Shuliveistrova said.
The company was talking with the government about reducing output to free up energy supplies needed elsewhere in the region, Rusal said.
Half of the residential buildings in Abakan, the capital of the Khakassia region where the plant is located, were left without power. Residents were stocking up on basic supplies and gasoline, Mayor Nikolai Bulakin said on Ekho Moskvy radio.
Abakan, home to 160,000 people, is located 180 kilometres north of the plant. Power shortages also were reported in the Tomsk and Kemerovo regions.
It was not immediately clear how many people were potentially affected by the accident. The plant satisfies 10 per cent of Siberia's energy needs, according to Russian media reports.
The Sayano-Shushenskaya plant was working at record capacity in June and July due to high water levels in the river, RusHydro reported last week. The plant went into operation in 1978.
Aging infrastructure has long been regarded as a key obstacle to Russia's development.
Analysts have warned that Russia needs to boost its power production significantly to meet the growing demand of industrial producers or it would face regular power shortages in the next several years. Yesterday's accident put these plans in jeopardy.