Accident at the Russian Biggest Hydroelectric Powerplant: Sayano-Shushenskaya, in Siberia.
Number of Units: 10.
Turbine Type: Francis (16 blades).
Rated Power: 650 MW each one.
Rated Discharge per Unit: 358,5 m³/s.
Nominal Speed: 142,86 rpm.
Net Head: 194 m.
Operation Date: 1978.
Runner Weight: 156 ton.
Runner Diameter: 6,77 m.
One of the world’s largest hydro-electric plants, this dam is 245 m (800 ft) high and stretches 1 km (0.6 miles) across the Yenisei river.
Opened in 1978, the station provides a quarter of RusHydro output and is a major power supplier to at least two smelters owned by United Company RUSAL, the world’s largest aluminium producer.
The hydroelectric power station is located on the Yenisei River, near Sayanogorsk in Khakassia, Russia. Before the accident, it was the largest power plant in Russia and the sixth-largest hydroelectric plant in the world.
ACCORDING TO THE OFFICIAL REPORT, DATED FIRST DAYS OF OCTOBER, THE COLLAPSE WAS DUE TO FATIGUE AND VIBRATION OF THE TURBINE.
At 08h 13m local time (00h 13m GMT) on 17 August 2009, the station suffered a catastrophic “pressure surge” in turbine known as a “waterhammer”. The sudden water pressure surge resulted in the ejection of turbine 2 with all equipment, a total weight some 900 tons, from its seat.
Turbines 7 and 9 also suffered from severe damage, while the turbine room roof fell on and damaged turbines 3, 4 and 5. Turbine 6, which was in scheduled repair at the time of accident, received only minor damage as it was the only one of the station’s 10 turbines that did not receive electrical damage due to shorting of transformers, and it will be restarted as soon as possible.
Water immediately flooded the engine and turbine rooms and caused a transformer explosion.
On 23 August 2009, authorities said 69 people were found dead while 6 people are still listed as missing. Efforts to pump flood water from the engine room and complete a search for the missing workmen are expected to take 3 to 8 days.
Consequences of the accident:
It will cost at least $310 million.
A long time to repair the damages.
The production of more than 500,000 tons of aluminum will be lost.
Oil slick is travelling down the river.
It is not clear how many people were potentially affected by the accident.
The plant satisfied 10% of Siberias energy needs.
Aluminum smelters consumed over 70% of the energy generated by the power plant.
Data taken from Euler Cruz & Rafael Cesário presentation (Brazilian consultants).
Antolín Martínez A.