Causes behind Sayano-Shushenskaya HPP accident still unclear

A day of mourning is being observed in the Khakasia republic in southeastern Siberia for the victims of Monday’s accident at the Sayano-Shushenskaya hydroelectric power plant. The latest reports say 12 people were killed but the death toll may rise.

Russia’s largest power generating plant, Sayano-Shushenskaya was stopped in the early hours of Monday after the turbine room partially collapsed. Three generating units were severely damaged and two others are heaped with metal debris. Despite a leak of transformer oil into the Yenisei river, the ecological damage has been minimized thanks to the authorities’ urgent response.

A criminal investigation has been launched. A group of experts comprising leading hydroelectric power specialists is examining possible technical faults behind the accident. The experts have asked journalists to refrain from preliminary conclusions or unchecked versions. So far, one thing clear is that the main cause is a hydraulic impact. Water falls on a turbine through special pipes at a giant speed from the height of more than 200 meters. But the waterfall can be regulated with the help of a special girder than can be either open or shut. A girder failure may cause an emergency. In this case, the impact may be much higher than the turbine can withstand. Valentin Berlin, a hydropower specialist and a member of the commission, explains:

A loss of pressure might have caused the girder to shut. If the loss occurred in the power house, it might have shut spontaneously.

Experts have ruled out a terrorist act, a transformer blast or repair failure. Energy Minister Sergei Shmatko told reporters:

Earlier assumptions that the accident occurred due to a transformer explosion or repairs have not been confirmed. More weighed conclusions can be made after we get into the collapsed turbine room.

Mr. Shmatko agreed that tighter control over electric power plants maintenance may be needed. The Energy Minister suggests placing repairwork at power generating facilities in Siberia under direct management. Their owners are currently evaluating the scope of repairs needed to be done and possible deadlines.


Vyacheslav Solovyov