Deadly Catastrophic Failure at Russian Hydroelectric Dam

August 19th, 2009
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At 8:13 local time this morning, the largest single hydroelectric dam in Russia experienced a catastrophic failure that destroyed much of the turbine hall and is feared to have killed dozen.   As of the most recent reports, at least twelve have been confirmed and seventy two are missing and presumed dead.   The incident occurred at the Sayano–Shushenskaya hydroelectric power station in Siberia – the largest hydroelectric power station in Russia and the sixth largest in the world.   The massive facility is equipped (or was equipped) with ten turbines with a combined output of more than six gigawatts.  The dam represents nearly 25% of the current hydroelectric capacity of the Russian Federation.

The accident heavily damaged the dam’s turbine hall and power generating equipment.  According to the dam’s operator, RusHydro, two of the turbines have been completely destroyed and at least two others are very heavily damaged. Assessments of the damage continue to be made and at this time, it is too early to know the full extent of the losses, although it is thought to be well into the billions of Rubles.  (At least 100 million USD, and possibly far more)   Repairs are expected to take years, although officials hope to have some power generation restored within 2-3 months.

It is important to note that at this time, all information indicates that the dam itself has not been damaged and remains structurally sound. The design of this dam has the powerhouse off to the side of the main structure.   This is where the accident occurred and thus a dam failure is not of concern.   A complete failure of the dam could result in mass casualties well into the tens of thousands.   Past reports have indicated concern over the integrity of the dam itself, especially during periods of high flooding, but this incident should not cause any immediate danger of a failure of the dam structure.



There have been local effects, however.   The region has experienced power failures due to the shortage of generating capacity.  The dam provides power to several large aluminum smelters, some of which have been completely shut down due to blackouts.   Although some of the smelters continue to operate on alternate power sources, they have had to reduce their production capacity.   These smelters are the region’s largest employer.   Additionally, the incident caused a major spill of transformer oil. It is unknown whether PCB’s may have also been released.

The exact cause of the accident remains under investigation.   However, it appears that the incident began with the failure of a large oil-filled transformer at the power plant.   Reports indicate that there was repair work being done on the system at the time of the incident.   Transformer failures are not entirely uncommon and most power plants are equipped to deal with these kind of incidents.   However, it appears that the failure of the transformer may have lead to a mechanical failure of the generators at the plant.   A sudden loss of load could cause the turbines to over-spin, putting them past their design limits.    Loss of phase or sudden loads, such as from a short circuit, can also subject the turbines to enormous mechanical stress.

There are safety systems which should cut the water flow in this circumstance and prevent short circuiting or phase loss on the turbines, but it appears that there was some kind of multiple systems failure in this case.   Clearly things went very very wrong.

This is not the first time this kind of thing has happened.   In 1949, the much smaller Ocree hydroelectric facility in the US experienced a catastrophic failure which destroyed the turbines and generators at the plant.   The event appears to have been triggered by a control problem which caused the turbines to temporarily disconnect from the grid load, causing them to over-spin and drop phase with the power grid.   The resulting mechanical forces ripped the turbine-generator units from their mountings send one flying through the powerhouse wall.    Plants are equipped with numerous safety systems to avoid such mishaps, but as this event shows, things still go wrong

There are already several videos on youtube which show the extreme damage caused by this incident.  Worth checking out.


This entry was posted on Wednesday, August 19th, 2009 at 12:00 am and is filed under Announcements, Enviornment, History, media, Misc, Politics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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24 Responses to “Deadly Catastrophic Failure at Russian Hydroelectric Dam”

  1. 1
    BMS Says:

    Leave it to renewables to outdo the Chernobyl accident.


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  2. 2
    Mister Fisk Says:

    Short circuits happen. Sudden losses of loads happen. Trees fall on power lines. Transformers catch fire.

    Every designer of a power plant is aware that these events occur and that the equipment will eventually face them. This is why there are circuit breakers and automatic diversion valves and kill switches and so on. They shouldn’t just be there in one case, they should be redundant.

    It looks like tether there was a short that put a huge load on the generators or maybe a fault that caused a huge reduction in load. In both cases, there should be something to stop any problems. The fact that its tied to the grid should offer some buffering. Maybe it lost the grid connection? In such a case, that is why there are governors to stop over-spin and if they fail, there is usually a fail safe like a centrifugal valve that is forced closed if it exceeds a speed.

    Usually there is a simple circuit breaker that cuts it off and also closes the gates on the turbine if there is a big problem.

    Even if that all fails, there should be a last line of defense like a connector that can act as a big fuse and will be sacrificed to save the generator or even a shaft that is designed to break in a predictable place if the system exceeds a load and therefore stops it from flying apart.

    Maybe I shouldn’t speculate, but I am inclined to suspect that there is more to this. I am thinking that there is a high likelyhood that someone cut a corner somewhere and when they go back and investigate this they’ll see someone jury-rigged some way of defeating the safety systems. Maybe someone was tired of the fuse constantly blowing for no apparent reason and so they decided to just take it out and shove a piece of copper pipe in. Maybe someone figured it was easier to bridge a broken circuit breaker than fix it.

    I don’t know for sure, but this shouldn’t happen if things are done by the book.


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  3. 3
    BMS Says:

    Maybe it’s a sabotage plot by Gazprom to boost profits.


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  4. 4
    Finrod Says:

    This really is a terrible thing. Hydroelectric dams are great for producing really cheap, almost emission-free electricity, but they’re occasionally subject to failures such as this, and sometimes far worse, such as the disaster in China in 1976.

    If only there were some way to make Hydroelectric dams as safe as nuclear power plants.


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  5. 5
    Russ Says:

            Finrod said:

    If only there were some way to make Hydroelectric dams as safe as nuclear power plants.

    Hydroelectric dams can be perfectly safe if they’re properly built and operated and have the capacity to deal with the amount of flooding that the area can get. It’s all a matter of standards. Nuclear plants are built and operated to the highest standards around and are constantly being inspected for safety and having their systems tested.

    The disaster in China was due to poor planning, failure to manage the water flow and construction bellow what it should have been. It’s comparable to Chernobyl, because both were examples of shoddy building, bad designs and corners cut when they were run.

    I don’t know that dams can ever be as safe as nuclear plants, especially earthen dams, but the issue is not that they’re always dangerous. There are many thousands of dams around, big and small, some over one hundred years old. They don’t get constant maintenance and attention to problems. Even known safety issues fester.

    A nuclear plant could also suffer a catastrophic mechanical failure of the turbines, if the safety procedures and systems were not all up to snuff. It is early to tell, but I do think that in all likelihood, things were not “done by the book” here.


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  6. 6
    Dave G Says:

    Wow. That is certainly catastrophic. Damn!


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  7. 7
    Engineering Edgar Says:

    I am really confused about what happened here exactly. The first reports I read all said that this was caused by a transformer explosion and that the explosion caused the damage. That makes no sense. Transformers can arc and they can catch fire and sometimes dramatically burst into flames, but they don’t go off like a bomb and create an explosion. Others said that the failure somehow damaged one or more of the turbine ducts and let all the water in doing the damege. Again, this doesn’t make much sense to me. For one thing, the transformer would probably be outside the turbine hall, and the video appears to show arcing early on in the event. I also saw something that claimed it was was a sudden surge of water from a gate opening improperly or something. The turbine should be able to take that without being destroyed (damaged, maybe, but not destroyed to this level).

    I think the idea of it being mechanical stress caused by a catastrophic failure of the electrical system is the one cause that makes sense. That still *shouldn’t* happen, because there should be some basic failsafes like big breakers and even if it were a loss of load, overspin should force the gates closed. Also, usually that’ll cook the bearings long before the turbine gets heaved out.

    I’ll be interested to see how the investigation turns out.


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  8. 8
    apotheosis Says:

    Jeez. Like the Russians didn’t have enough problems already. Those guys just can’t catch a break, can they?


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  9. 9
    Chem Geek Gregor Says:

    “Should have fail-safes” “Should have breakers” “Should be designed to handle this”

    Yes, it should. However, this was built by the Soviet Union in the same era that saw the construction of enormous nuclear reactors that were moderated by graphite, cooled by water, had a huge positive void coefficient and were built without even the most basic containment building.

    Clearly they were more than willing to build things that were inherently unsafe and contained numerous severe design flaws.


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  10. 10
    Chuck P. Says:

            apotheosis said:

    Jeez. Like the Russians didn’t have enough problems already. Those guys just can’t catch a break, can they?

    Sure they can. They’re making money hand over fist off the bulk of western Europe due to shortsighted energy policies on the part of European Greens.


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  11. 11
    Jaro V. Says:

    As discussed above there could be many reasons leading to the catastrophic failure. What was possibly missing was a good responsible operation and/or maintenance. It should have been based on a solid reliability analysis , possibly FMECA.
    At the end it had to be a mechanical failure of turbine components; could be failure of the bolts of the head cover which is bolted to stay ring. Care is required that these high quality bolts are tightened/prestressed to the same level of tension to share the load.
    Anyway, it should not have happened to the station of this importance


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  12. 12
    Kingbob Says:

    So between 12 and 60 dead, and potentially a hundred or more injured. And this is meant to be safe, clean, green, hydro-electricity.

    So how many people now has “safe” energy killed vs nuclear power?


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  13. 13
    drbuzz0 Says:

            Kingbob said:

    So between 12 and 60 dead, and potentially a hundred or more injured.

    The latest numbers I have seen for the total is that there are 17 confirmed dead (meaning that they have found their bodies) and 58 missing and presumed dead At this point, it is no longer considered a “rescue” operation because it is considered highly unlikely that any of the remaining lost will be found alive. Finding all the bodies could be very difficult as some may have been washed some distance by the torrent of water and possibly not in one piece.

    It has been about two days to track down any workers who were declared “missing” from the site, so at this point, it looks like the death toll is going to be in the neighborhood of 75, possibly give or take a few.


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  14. 14
    FooBarEr Says:

    What happened to cause this? I keep reading the news. First they said it was an explosion and then they said an unexplained surge of water and then they said they think it’s a broken turbine blade? Which one is it??

    It does not look like an explosion to me. I don’t know all the details, but it looks like one of those big generators just flew apart or something and then water started gushing out the roof.

    Any idea what report is correct?


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  15. 15
    Engineering Edgar Says:

            FooBarEr said:

    Which one is it??

    It does not look like an explosion to me. I don’t know all the details, but it looks like one of those big generators just flew apart or something and then water started gushing out the roof.

    Any idea what report is correct?

    Not an explosion. That term seems to be used to just describe everything flying apart. It was some kind of massive mechanical failure where one or more turbine gensets broke lose violently and there was also the massive volume of water that came in.

    It is not known yet what caused this, but it was widely reported that a transformer failure started this whole thing. If that’s correct it could have been a sudden electrical load or maybe a sudden loss of load (depending on the type of failure, like was it a short or a break). Also, it’s possible that the turbine wasn’t properly bolted down or something.

    We really don’t know what touched this off. I suspect more than one major system was not functioning like it should have been.


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  16. 16
    Soylent Says:

    Edgar, transformers contain large volumes of oil coolant, which if heated sufficiently can cause a BLEVE and big fireball.

    E.g. see this substation fire: http://www.youtube.com/watch?v=WkDCS8xeobg


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  17. 17
    Engineering Edgar Says:

            Soylent said:

    Edgar, transformers contain large volumes of oil coolant, which if heated sufficiently can cause a BLEVE and big fireball.

    E.g. see this substation fire: http://www.youtube.com/watch?v=WkDCS8xeobg

    Oh I know, and I’ve seen it (Not in person, but I’ve seen the results), but it’s really a burst of flames if the oil gets sprayed. It’s not like it’s a concussion that it sufficient to blast a huge turbine genset through the ceiling. That’s my point. Whether or not there was a transformer ‘explosion’ that was not really what the big problem was.

    Sorry if I was not clear.


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  18. 18
    dmfdmf Says:

            Chem Geek Gregor said:

    Yes, it should. However, this was built by the Soviet Union in the same era that saw the construction of enormous nuclear reactors that were moderated by graphite, cooled by water, had a huge positive void coefficient and were built without even the most basic containment building. Clearly they were more than willing to build things that were inherently unsafe and contained numerous severe design flaws.

    This is correct but there is more to the story. At Chernobyl they disabled 2 or 3 safety systems (I forget the exact count) and put the reactor into a dangerous operating zone (low power, few voids) while trying to run a turbine spin-down test before a scheduled shutdown. Pressure and orders from Moscow apparently played a role, as the previous lead engineer or plant manager (I forget which) was fired for not getting the test done before the last planned outage.

    My guess is that this accident is probably due to poor maintenance and/or not following policies and procedures. It will be interesting if there was any political pressures involved such as with Chernobyl.


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  19. 19
    An Actual Scientist Says:

    It was both, really. The RBMK was not a design that was inherently safe in the same way a PWR is. It was a reactor that was fairly easy to create an out of control situation with if you just did a few of the wrong things. It had active safety systems to stop this, but it let the operators override these and run it in a manner it shouldn’t have ever been run. It was the combination of the two factors: design and operation. Really both were unacceptable.

    The containment of the reactor: it was supposed to have a full containment structure. That was in the original design specs for the RBMK. This was omitted in the final construction of most of them. Chernobyl had nothing more than a roof you might see on a warehouse.


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  20. 20
    Q Says:

    I was thinking, since this is going to cause an energy crisis for months and won’t be back online 100% for years, I wonder if this could cause gas supply shortages. We all know Europe is dependent on Russia for most gas, but if the Russians need it to fill the generating gap they might end up without enough gas well capacity to provide gas to both their own needs and those of the rest of Europe. In that circumstance they could cut down on exports to use what they have.

    Just speculation, mind you.


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  21. 21
    Brent Says:

    Now we see that the turbines were 31 years old. The design life of the turbine is 25-30 years. The direct cause was a water hammer caused by the wicket gates slamming shut( very fast). and the resultant reverse water hammer causing the turbine (# 2) to be lifted up flooding the turbine house and the transformers then shorting out and causing the roof to collapse.

    http://mail.google.com/mail/?ui=2&ik=aeccc6985c&view=att&th=123617e71f53a264&attid=0.1&disp=attd&zw

    The cause of the wicket gates closing could have been a log getting into the turbine( which would mean the trash gates had a hole in them) and striking the wicket gates or it could have been a wicket gate coming apart throwing a piece of junk into the other gates.


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  22. 22
    My Chernobyl Says:

            An Actual Scientist said:

    It was both, really.

    The RBMK was not a design that was inherently safe in the same way a PWR is.

    It was a reactor that was fairly easy to create an out of control situation with if you just did a few of the wrong things. It had active safety systems to stop this, but it let the operators override these and run it in a manner it shouldn’t have ever been run.

    It was the combination of the two factors: design and operation. Really both were unacceptable.

    The containment of the reactor: it was supposed to have a full containment structure. That was in the original design specs for the RBMK.

    This was omitted in the final construction of most of them. Chernobyl had nothing more than a roof you might see on a warehouse.


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  23. 23
    My Chernobyl Says:

    To be exact, the Chernobyl “containment” consisted of a 600-ton “bioshield” on top of the reactor vessel (The erupting fuel famously ejected this massive object as though it were not even there)> But to your point, the reactor was not “contained”, in any appreciable sense, just “shielded” one the top side.


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  24. 24
    EP Says:

    After the fact, I saw one post that made perfect sense. The head bolts on the turbine were not torqued properly. This from a Canadian fellow that has seen the effects of this.


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