OREANDA-NEWS. On 10 September 2009 was announced, that a meeting was held of the Board of Directors of JSC RusHydro in presentia to discuss measures to eliminate the consequences of the accident that occurred in the turbine room of the Sayano-Shushenskaya HPP on 17 August, 2009.

The Board of Directors of JSC RusHydro has heard and taken note of information about the situation surrounding the accident at the Sayano-Shushenskaya HPP, including a general description of the hydro-electric power station, of the accident and the current status of restoration work.

The accident at the Sayano-Shushenskaya HPP occurred on 17 August, 2009.  At the time of the accident, 9 of the Sayano-Shushenskaya HPP turbines were in operation (hydro-turbine No. 6 was in reserve).  The total active capacity of the turbines amounted to 4400 MW.  As a result of the damage to hydro-unit No. 2, the reason for which is being determined, water was ejected from the turbine crater.  The reasons for the accident are still being investigated.

As a result of the accident, MARKhI construction elements of the on the sector from hydro-units 1 to 5 and the roof at the turbine room service level (level 327) partially collapsed; the support columns of the building and level 327 were damaged and partly destroyed, as were the regulation, control and protection systems of the hydro-units at this level; 5 phase power transformers received mechanical damage of different degrees; construction elements of the transformer site in the area of blocks 1 and 2 were damaged. 

The water caused electrical and mechanical damage to different extents to all the HPP’s hydro-units, including the following:

∙    hydro-generator 5 – preliminary estimate – electrical damage to the generator,

∙    hydro-generator 6 – damage to the generator owing to flooding,

∙    hydro-generators 3 and 4 – electrical and mechanical damage to a medium degree and varying degrees of damage to the construction elements,

∙    hydro-generators 1, 10 and 8, – electrical and mechanical damage to a more serious degree and varying degrees of damage to the construction elements,

∙     hydro-generators 7 and 9 – serious damage to the construction elements and complete destruction of the generators,

∙     hydro-generator 2 – complete destruction of the construction elements, the generator and the turbine.

All the technological systems for the entire power station located at the 327 and lower levels were flooded and damaged to differing degrees.  Cable tunnels and galleries of the tailrace in the area of hydro-generators 2, 7 and 9 collapsed.

The personnel of the power station and contractor organisations managed, by 9 hours 20 minutes to close the accident and repair valve of hydro-generator 2 and cut off the inflow of water into the turbine room through the destroyed hydro-generator 2.  At 11 hours 40 minutes, the gates of the spillway dam were opened and the release balance through the hydro-power complex restored to the set regime.  Until the valves of the spillway dam were opened, the Mainskaya HPP regulated the sanitary release for the River Yenisei. 

During elimination of the consequences of the accident at the power station by the efforts of the Ministry for Emergency Situations, together with the Ministry of Power of Russia, a total of up to 2.7 thousand people have been involved in the search and rescue work (including about 2 thousand at he HPP itself), plus over 200 pieces of equipment, including 11 aircraft and 15 water craft.  Over 5 thousand cubic metres of debris have been cleared and more than 277 thousand cubic metres of water pumped out.  9683 metres of booms were set up and 324.2 metric tonnes of oily emulsion collected up.

By 25 August, rescue work at the HPP was drawing to a close.  14 people were rescued and the bodies of 73 were found at the accident site.  Another two are still missing. 

On 23 August, 2009, divisions and brigades of professional repair workers, installation and other power industry experts began arriving at the power station from other parts of Russia.  It is planned to bring the numbers engaged in the restoration work up to 2500, the figure fluctuating depending on the volume and complexity of the tasks.

For the purpose of delivering workers and freight to the accident site, from 19 August, 2009 through 29 August, 2009, JSC RusHydro organised 12 charter flights, including 1 Ministry of Emergency Situations aircraft, which brought in 700 people and 85 metric tonnes of freight.

To co-ordinate the interaction between the various organisations involved in performance of the accident and rescue work, and subsequently for the purpose of operational regulation of aspects of restoring the HPP, a Ministry of Power of Russia headquarters has been set up to work round the clock, headed by the Deputy Ministry of Power. 

Restoration is currently under way at the power station.