Russell W. Ray, Associate Editor, Hydro Review Worldwide
March 30, 2010 | 0 Comments
Rebuilding Russia's largest power plant, the 6,400-MW Sayano-Shushenskaya hydroelectric plant in southern Siberia, may take longer than expected as engineers deal with challenging logistics, a rare design, and uncertainty surrounding the accident that killed 75 people in August 2009.
"The vibration itself was a cry for help from the machine that something was going on. That machine, with that vibration level, should probably have been the last unit on and the first unit off. In the 12 to 14 hours preceding the failure, they ran that machine in zones that most places don't let their units even run." -- Donald Erpenbeck, vice president of MWH Americas Inc.,
Russian equipment supplier JSC Power Machines is supplying the damaged plant with ten new turbines, nine new generators, and six new excitation systems for 11.7 billion rubles (US$392 million). Power Machines General Director Igor Kustin said the manufacturer will be “taking into account corrections” deemed necessary in a report by Rostechnadzor, the government watchdog that investigated the disaster.
RusHydro, the plant’s owner and operator, was the second-largest hydropower producer in the world, with 25,400 MW of capacity. Sayano-Shushenskaya accounted for a quarter of that output. Before the accident, Sayano-Shushenskaya was the largest hydropower plant in Russia and the sixth largest in the world.
On the morning of Aug. 17, 2009, Unit 2 was operating under load, with the rotor spinning at nominal frequency, according to RusHydro. From 8:12 a.m., output from unit 2 was reduced by an automatic power regulator, the company said.
According to RusHydro, six of the ten hydro units were destroyed. In materials provided to HRW-Hydro Review Worldwide, RusHydro said: “As the turbine’s output power entered into a power band not recommended for long-term operation, the bolts keeping the turbine’s cover were broken. Under water pressure in the hydropower unit, its rotor with the turbine cover and the upper bracket shot up. After this, water sprouted from the cavity of the turbine and flooded the machinery hall in less than a minute.”1
RusHydro: Restoration work on schedule
In the short-term, RusHydro said it plans to restore four units in 2010.
Yuri Gorbenko, a member of RusHydro’s Management Board, said the restoration work is on schedule and involves 2,508 workers and 91 pieces of equipment.
On February 24, 2010, the company restarted unit 6, which can generate up to 640 MW. From the plant’s central control board, Russian Federation Prime Minister Vladimir Putin launched unit 6 into production. Unit 5 was scheduled to be placed back into service in March 2010.
The operation of units 5 and 6 means the introduction of 1,280 MW of capacity, minimizing flooding risks and guaranteeing water supply to residents and industrial operations, RusHydro said.
The launch of unit 6 was carried out ahead of schedule. Units 3 and 4 will be put back into production by the end of 2010. Following these launches, the Sayano-Shushenskaya plant’s installed capacity will stand at 2,560 MW.
Putin said the Russian government plans to allocate more than 10 billion rubles to the restoration project in 2010 and 3.5 billion rubles for construction of the first stage of a shore spillway.
The long-term plan calls for the installation of ten new units by 2014. Power Machines will supply the equipment.
Under its contract, Power Machines will complete six hydro units in 2011. The rest will be completed in 2012. Each unit will have a life span of 40 years and will operate at 96.6 percent efficiency.
“This large transaction is vitally important for the restoration of the company’s Sayano-Shushenskaya hydropower plant,” said Evgeny Dod, chairman of RusHydro’s Management Board, “and it is also extremely critical, particularly in terms of delivery guarantees and technical tracking, for the equipment operating process.”
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