Fee-for-progress - the biggest accident on hydroelectric power station

In August this year will mark 5 years since the accident at the power plant. Until now, the region face the consequences of the disaster. Hydroelectric power did not work in full capacity. The families (75 people) continue to mourn their loved ones. Technological disaster – the price that mankind pays for the development of scientific and technological progress. Remember some of the crushing world of accidents at hydroelectric dams.

 

 

China, Henan province, dam, Banqiao

 



This dirt dam (height 24,54 m, length 118 m) was built on the river Guha in 1952. Original purpose: the protection of farmland of the province by the floods. Later added to this power generation. The number of dead and injured from the consequences of this disaster is unparalleled in the "black list" of hydropower. On the night of 8 August 1975 the strongest flood broke through the dam Shimantan that was higher up the river, Guha. Water with a roar rushed down. Reaching the dam, Banqiao, the stream flowed through her comb, and destroy the building to the ground within a few minutes. The resulting wave height of 7 meters per hour flying distance 55 km away, Destroying everything in its path, the water flooded the plain up to 15 km wide. From the water head, the blow falling of the walls and stones in an hour after the accident killed 26 thousand people. Later sank another 145 thousand. Had destroyed 60 of dams, dozens of road bridges rail journey. Destroyed lines of communication. This greatly hampered the rescue of the victims. The flood has claimed 300 thousand heads of livestock. The water flooded a huge area of fertile farmland. Due to famine and cholera epidemics, the number of victims has risen significantly. According to various estimates, it reached the appalling number of from 170 to 230 thousand people. In the number of fatalities and the injury suffered, this accident is considered the largest in the history of the plant.

Reasons

All man-made disaster caused by many factors one of the main "human".

The destruction of the dam, Banqiao is no exception. Conducted investigation into the accident revealed serious problems in the technical condition of the dam and the fact that they have long been known to the top leadership of China's energy. Because of blunders in the construction, shortly after the whole structure was covered with cracks. The dam strengthening steel structures was carried out by Soviet specialists. There were other technical problems.

Due to cost considerations, the dam passed with five floodgates, although it was planned to build 12. The reduction of the floodgates has affected other dams on the river, Guha. For this reason, 8 August 1975, they were unable to withstand the load of the wave, and was destroyed. The designers have calculated the dam Banqiao for floods that occur once in 1000 years (306 mm precipitation per day). But at the time of the accident his the destructive force of the flood exceeded all estimates. This one of the top leaders of China could not imagine, and cheapening the construction of the dams had seemed a reasonable solution. Against a common thrill practice the savings made by only one specialist hydrologist Chen Xing. He has repeatedly stated publicly that the reduction of gutters puts the dam, Banqiao in a technically dangerous position. But the opinion of the engineer was not taken into account. For integrity, he was dismissed and accused of trying to waste money the Chinese people. Unfortunately all Sin was right.

Weather

Since the end of July of 1975 during the week over China raged, super Typhoon "Nina". Even after it weakening continued torrential rains. For the entire day on August 6 dropped a record rainfall of 1,631 mm above normal 2 times! Several provinces of the country were covered by the flood.

 

Reservoir Banciao were overcrowded. Required urgently to pull the excess water. But to make it energy drinks banned because areas downstream of Juha had already been impounded. When the party comrades took the decision on the opening of floodgates, communication was lost with the dam. The management of the dam decided to act on your own risk — let the water run. But it was too late. By the time, code, station Director gave the order to open the floodgates, they were thoroughly covered with mud. The last link in the chain of events – the destruction Shimantan the top of the dam, which was upstream from Banciao. Mass of water, destroying one dam, rushed to the second and swept her up in a few seconds. Was the morning of August 8, 1975. Slept in their homes, people were helpless before the madness of the elements. This explains the appalling number of casualties in the first hour after the accident. The destruction of roads and communications links disrupted the work of saving the victims. The water destroyed the food stocks, medicines, herds of cattle. In the flooded areas of aid dropped by helicopter. Famine and epidemics. In the funnel of the disaster were drawn 11 million people.
In 1993, the dam was rebuilt and put into operation. In the restoration works took part rehabilitated the hydrologist Chen Xing.

 

Italy, the dam Vajont


Hydroelectric power plant abandoned since the disaster — more than 50 years. 5 concrete-arch structure (261,6 m, thickness at the base of 23 meters) is located on the river Vaynot at the mount Current in the province of Belluno. In October 1963, the late evening into the reservoir slipped a huge part of Monte Current, a long stretch of 2 km and a width of almost 1 km. of the Reservoir to 175 m was filled with rocks. Water rushed over the crest of the dam. Water column shot up to a mile above the dam, and rushed down. Giant wave Sasa) 90 m in height swept through the area at speeds of tsunami 8-12 m/sec. For 7 minutes after landslide she washed in the valley of the Piave river 5 villages. Seriously damaged and other settlements. According to various estimates, in the accident died from 1900 to 3000. By morning, the gorge was a huge lake of mud.

Reasons

The accident investigation found that the place for building designers was chosen incorrectly. The crust in this area is mobile, frequent small earthquakes and landslides. This was known to the company-by SADE, but she continued to work. Before the construction of the dam their concerns repeatedly expressed by the geologists. The construction of the dam began in 1957 and the first landslide happened 2 years later. Despite this, construction has not stopped. After filling the bowl reservoir with water (in 1960) the position of the stations some of the art seemed extremely dangerous. A year before the disaster, engineers of the company SADE (construction contractor) on the basis of long-term observations of problematic areas of the dam, warned their superiors of the impending threat of an accident. But the statement of the experts have ignored. Nobody reported a possible danger to residents of nearby villages.
The accident occurred on 9 October 1963 at 22.35 after long and heavy rains.

Punishment

The trial between the top managers of the company and the government of Italy continued for many years. Several specialists SADE was convicted and sentenced to short terms. One of the engineers committed suicide. Areas affected by the disaster, were given economic incentives. This has a positive impact on the economy of the region. Dam little hurt in the crash and is still in place. In 2001 he was made a feature film, restoring a chronicle of those events. Since 2002, dam Vajont became a popular tourist attraction.

 

Russia, the Sayano-Shushenskaya HPP


The largest (total capacity together with the Maynskaya hydroelectric facility-6721 MW) in the country powerhouse with a concrete dam with a height of 245m, with a length of 1066 m is 35 km from Sayanogorsk (Khakassia). Before the accident on 17 August 2009, the share of hydropower accounted for 15% of produced in the country of electricity. Share in world volume, 2%. Currently, the station operates at half of its capacity. The restoration work is not over yet. Late in the evening of 17 August 2009, with the increase of vibration on the unit 2 tore the cover of the turbine and put it up. Blow was such force that the lid is struck a concrete ceiling. In the engine room flooded water from the Sayano-Shushensky reservoir. A few minutes after destroying the engine room, the flow meter spilled out into the streets, and flooded the surrounding area, producing the road of strong destruction. All units of the dam were destroyed or severely damaged. Protection system did not work, the power plant was de-energized. At this time, the hydraulic unit No. 6 specialists carried out the repair. They worked in the internal space of the unit, under the floor of the machine room. Water from the destroyed unit No. 2 flooded the room for a few minutes. All the workers were killed. Later they are joined by other victims. The total number of deaths from the accident at the HPP – 75. Got serious wounds and injuries of 13 people. Water stopped flowing into the engine room only the next morning. By this time managed to manually search through the technological gates on the crest of the dam.
Because of the accident in the Yenisei river spilled out of 45 cubic meters turbine oil. Formed a spot with a length of 130 km. In fish farms at the Sayano-Shushensky reservoir killed 400 tons of industrial trout. To localize oil stain failed after a week. The size of the material damage emergencies Minister (at that time) Sergei Shoigu has compared the accident at the Sayano-Shushenskaya HPP with the destruction of the reactor at Chernobyl. Because of the accident been dead several large industrial enterprises, including metallurgical Sayanogorsk plant. Without electricity there were many cities and towns in Khakassia, Altai Krai. And also in the neighboring regions: Novosibirsk, Kemerovo and Tomsk. Soon the supply was restored by redistributing the load between the other power plants of Siberia. Restore the machine hall, reconstruction of old and installation of new units cost "RUSHYDRO energy holding, the owner of Sayano-Shushenskaya HPP) to 20 billion rubles.

Reasons

Rostekhnadzor conducted an investigation of causes of accident on August 17. In addition to technical reasons, he again attended the "human factor". Technical problems: fasteners (studs) covers the turbines could not withstand the increased vibration because of the "fatigue" of metals collapsed. The pressure of the water tore the cover. The accident could have been prevented in a timely manner after the repair. The chief engineer of the station ignored the critical sensor readings. The user GES for many years made the work of unit No. 2 in unsatisfactory vibration mode. A special Commission of Rostekhnadzor, which conducted the investigation, found responsible in the accident, many top managers of Russian energy: the former head of RAO "UES of Russia" Anatoly Chubais, the Deputy Minister of energy Vyacheslav sinugin etc. And corresponding member of RAS Anatoly Dyakov and Ambassador for special assignments of the Russian foreign Ministry Igor Yusufov. He directed the Ministry of energy from 2001 to 2004 they All knew about the emergency situation Sayano — Shushenskaya power station accident that took place there until August 17. However, any drastic measures to resolve technical issues was not accepted.

Punishment

The investigation into the accident at the Sayano-Shushenskaya HPP was carried out for 3 years. The first criminal case was closed by the Prosecutor General's office due to the occurrence of a limitation period in 2011. The guilt of the accused was changed to a more serious article of the criminal code. However, the court verdict is not so far. The meeting was postponed many times for various reasons, including from-for absences in court of the counsel for the accused. The prosecution indicted former station Manager, chief engineer, his two deputies, experts of monitoring equipment of Sayano-Shushenskaya HPP. The list of defendants 7 people. The investigation was completed in August 2012. More years the accused got acquainted with case materials (1213 books).

Resonance

Residents of Khakassia and Krasnoyarsk Krai (1823 people) in November 2009, appealed to the Supreme leadership of Russia with a proposal to close the Sayano-Shushenskaya HPP.
25 km from Krasnoyarsk on the Yenisei river is another powerful plant. In case of destruction of the Sayano-Shushenskaya dam, the wave comes to Abakan (the capital of Khakassia) for 60 minutes, until the Sayanogorsk in 7 minutes. But even more terrible consequences will occur when the wave gets to the Krasnoyarsk hydroelectric power station. If that will not stand, million city will be flooded. For this reason, after the accident on 17 August in Krasnoyarsk region for a long time remained tense emotional atmosphere, people were scared.

 

 

 

 

Source: alternativenergy.ru