Sayano-Shushenskaya Hydro Accident

The number of people killed in the accident at Russia’s largest hydroelectric power plant increased from 67 to 69.

Six persons are still missing, an official with the Russian EMERCOM said Sunday.

Specialists and rescuers – over 2,000 people – are currently involved in the works to liquidate the consequences of the disaster at Sayano-Shushenskaya Hydroelectric Power Plant. Employees of the plant take part in the works to recover the missing people from the huge engine room of the plant.

Prime Minister Vladimir Putin signed a special decree Saturday to assign one million rubles (approximately $32,000) to each family of those killed in the accident. In the meantime, the relatives of the killed workers seek much larger compensations from RusHydro – the company which operates the Sayano-Shushenskaya Plant. They want the company to pay five million rubles to each family. In addition, they want the authorities to guarantee free higher education to the children, whose parents were killed in the disaster. Many of the relatives said that they would be ready to take a legal action against RusHydro.

The 2009 Sayano–Shushenskaya hydroelectric power station accident occurred at 00:13 GMT on 17 August 2009, (08:13 AM local time) when turbine 2 of the Sayano–Shushenskaya hydroelectric power station broke apart violently. The turbine hall and engine room were flooded, the ceiling of the turbine hall collapsed, 9 of 10 turbines were damaged or destroyed, and 75 people were killed. The entire plant output, totaling 6,400 MW and a significant portion of the supply to the local grid, was lost, leading to widespread power failure in the local area, and forcing all major users such as aluminum smelters to switch to diesel generators. An official report on the accident was issued on 4 October 2009.

Names of people killed and those who bear responsibility for the accident, and other data including a historical and technical review about the plant and plans for its future, are given in the report. The report states that the accident was primarily caused by the turbine vibrations which led to the fatigue damage of the mountings of the turbine 2, including the cover of the turbine. It was also found that at the moment of accident at least six nuts were missing from the bolts securing the turbine cover. After the accident 49 found bolts were investigated from which 41 had fatigue cracks. On 8 bolts, the fatigue damaged area exceeded 90% of the total cross-sectional area.

According to this report, on 17 August 2009 at 1:20AM (local time) there was a fire at the hydroelectric power station of Bratsk which broke both communications and the automatic driving systems of other power plants in the region, including Sayano-Shushenskaya. The situation was recovered on 17 August 2009 at 15:03. At 8:12AM local time, turbine 2's output power was reduced by the turbine regulator and it entered into the unrecommended powerband II. Shortly after this, the bolts keeping the turbine cover in place were broken, and under water pressure of about 20 bars (2,000 kPa), the spinning turbine with its cover, rotor, and upper parts started to move up, destroying machinery hall installations. At the same time, pressurized water flooded the rooms and continued damaging plant constructions.

According to Rostekhnadzor, the automatic shutdown system of the water intake pipes' gates failed after failure of the turbine 2. This accusation was dismissed by Rakurs, the company which designed the automated safety system for the plant.

The death toll from Monday's accident at Russia's largest hydro-electric plant has risen to 67, officials say.

They say eight people are still missing after a massive surge of water in the turbine hall at the Sayano-Shushenskaya plant in Siberia.

Rescue and clean-up operations are continuing, but officials say chances of finding any survivors are slim.

The cause of the accident on the plant on the Yenisei River remains unclear and an investigation has been launched.