Cook U1 Turbine Problems

[Rennhack]

I hear that DC Cook just had some issues with their turbine... like a thrown blade.

[retired nuke]

Hmmm, I remember the one at Salem - what a mess, shutdown too early to do the outage, had to get another turbine (Seabrook 2) screwed up schedules everywhere - hope nobody got hurt.

[Nuclear NASCAR]

The only thing I've been able to find so far is on Wikipedia it says there was a turbine building fire on September 20, 2008.

[fueldryer]

I hear that DC Cook just had some issues with their turbine... like a thrown blade.

The email that I got said that they had a fire in the main generator.

[Already Gone]

I just talked to a guy who talked to a guy who says that the turbine-generator train was a big wreck.  He says that the fire was caused by the messed-up bearings, which came from trouble with the new turbine rotors.

More and better details to follow.

[Rennhack]

Well... I live in the area, and have a friend or two that work there.  My information is all second hand and hear-say... so take it for what it's worth...

I'm told that it is a major mess.  There was an explosion that caused a lot of seismic damage.  Preliminary inspection suggests that the U1 turbine AND turbine deck would need to be replaced.  Pipes have been moved feet, not inches, insulation dislodged.... Some concrete damaged... you get the picture.

[Rennhack]

A news article:

http://www.woodtv.com/Global/story.asp?S=9046420&nav=0Rcedls9

BRIDGMAN, Mich. (WOOD) -- A fire at the DC Cook Nuclear Power Plant caused an emergency response Saturday after a fire in one of the generators.

The fire broke out at 8:05 p.m. Saturday in the unit 1 generator. Firefighters were called to the scene, and by 8:30 p.m. the flames had been knocked down.

The plant's policy though requires that the emergency plan be activated for any fire lasting longer than 15 minutes. Officials tell 24 Hour News 8 that at 8:18 p.m. Saturday the "Unusual Event" emergency plan was activated - that is the lowest of the four emergency levels. State and county officials were notified of the situation.

The emergency alert was deactivated at 4:09 a.m. Sunday.

The actual fire took place in the part of the plant where steam is transferred into electricity, nowhere near the nuclear reactor.

The incident did not pose any danger to the public. The plant has electricity in reserve, therefore the shutdown did affect customers.

Now an investigation is underway at the plant to determine what may have caused the fire and to see how much damage was done to plant.

I know that the fired departments fron 3 local towns responded...

[Rennhack]

As an aside note of trivia, Unit 1 has a General Electric turbine as opposed to Unit 2's Brown Boveri turbine.

[Already Gone]

Update on that trivia.  They replaced at least one of the GE turbines with Siemens-Westinghouse.  This is apparently the place where the damage started, but that could take months to sort out.

[Rennhack]

Update on that trivia.  They replaced at least one of the GE turbines with Siemens-Westinghouse.  This is apparently the place where the damage started, but that could take months to sort out.

I was told that Furmanite had just finished a repair of a hydrogen leak in that area a day prior to the incident...

Again.. this is all rummors.  Take it all with a grain of salt.

[Already Gone]

Yeah, all we really know is that the plant is a mess.  And, for people in our line of work, that means opportunity.

[Rennhack]

Yeah, all we really know is that the plant is a mess.  And, for people in our line of work, that means opportunity.

Well... Short term opportunity... but for the nuclear industry in general... its not a good thing.

[Fermi2]

Can't be any worse than the Fermi2 Turbine Event X Mas Day 1993. Turned the Turbine Building into a total trainwreck and put a million gallons of lake water into the TB Basement.
Also flooded the Radwaste Building.

Plant was down for over a year.

Mike

[Brett LaVigne]

I certainly hate to hear this news. It is not good for the industry. I haven't heard anything about anyone getting injured, anyone know?

[rlbinc]

I have no specifics, but the failure modes of turbine generators are easy to summarize from an SRO Instructor perspective...

Small imbalances or blade resonances can cause high vibration due to the large rotating mass and high speed.
If vibrations are allowed to persist, bearing clearances will enlarge due to accelerated wear.
As bearing clearances increase, two effects occur - both bad. Oil pressure lowers at the bearing with the highest clearance due to excessive drain flow. The Turbine Shaft gets an increasing amount of radial room to wobble around. Greater shaft movement exerts high stresses on Turbine Blades, particularly the longer ones in the late stages of the Low Pressure Turbine.
If a blade failure occurs - a piece of steel departs the Turbine assembly at near sonic speed - and collateral damage occurs to the Turbine Casing or condenser. (One rather notorious blade failure resulted in a blade landing in a corn field in the surrounding community.)
If a bearing failure occurs - a large oil leak will occur which will not stop until either the Turbine coasts down or theTurbine Oil reservoir empties.
In either case, the Hydrogen Seals on the Generator are quickly eaten up by excessive radial shaft movement and a Hydrogen Leak will occur.
Oil, Hydrogen, and friction heat combine to pose a threat of fire.

There's a lot of rotating energy in even a tripped Turbine Generator. Lots of mayhem can occur before the Turbine coasts down to a stop.

The root cause of the failure can be isolated down to technical issues over the weeks and months following a failure - the outcomes are pretty much the same. Smoke, fire, mechanical damage, and an extended outage.

[Rennhack]

Can't be any worse than the Fermi2 Turbine Event X Mas Day 1993.
Plant was down for over a year.

As I see it, the diff in 15 years is that NOW they are thinking about building more... 15 years ago they were not.  Bad press and an unfavorable election could put an end to to new construction.

[Dave Warren]

an unfavorable election could put an end to to new construction.

What are you trying to say?

[Laundry Man]

Of course Fermi is a BWR which just made the mess all the more a pain to clean up.  Worked a lot of hours that year.
LM

[retired nuke]

No info on turbine damage beyond the fire and safe shutdown of the reactor on the NRC site....

http://www.nrc.gov/reading-rm/doc-collections/event-status/event/en.html#en44507

[Rennhack]

Of course Fermi is a BWR which just made the mess all the more a pain to clean up.  Worked a lot of hours that year.
LM

I'm told that U1 insulation is propbably asbestos... not a rad mess... but still a mess to clean up.

[Already Gone]

Mike,
I wouldn't be so concerned about the effect of this incident on the future of nuclear energy.

This kind of thing happens a lot in fossil plants.

The good side is that the nukes might start to remember why this is a rare occurrence in their plants.  They might realize that all that maintenance they were doing was really a good idea, and the more recent trend of blowing it off is not so good.

I have seen people make big decisions with one eye on the megawatt meter that turned out to be wrong.  Dresden deciding to go back to full power with a cracked generator rotor comes to mind.  They were lucky that it didn't fail, but they were coming down to fix it and turned right around and cranked her up to max without knowing what was causing those vibrations.  All they had to do was stop the thing and look at it to find the damage.  But, that would not have kept the cha-ching coming in.

I mean really!?!?!  Furmanite???  C'mon!!  You don't Bondo the Space Shuttle, and you shouldn't bubble gum the generator either.  Even if that wasn't the cause, it is indicative of the mindset that a band-aid repair to keep the money flowing is okay.  I really wonder how long these guys drive their Mercedes cars with the oil light on.

The best thing that can happen to the future of nukes is to take care of the aging plants that are running now, and build their replacements soon.  the "newest" commercial reactor in this country is over 20 years old.  If you look at the time it takes to build and get a nuke on the grid, the only smart course of action is to get a license extension for your current plant and start building its replacement the same day.

Anyway, the death of the industry won't come from equipment failure, but from the failure of management to do their job and prevent that failure.  Davis Besse was the wake-up call, but maybe this is the buzzer that goes off after they hit the snooze button.

GREED screwed up our economy in general, and it will screw up the smaller economies of energy production too.  Nuclear licensees need to wake up and be responsible to someone other than the Wall Street pundits - or else maybe the industry should die.

[Melrose]

The turbine casing and hood are split and dented.  Chunks of debris, piping, concrete etc are all over the deck.  Looks like a steam line is twisted, even material outside was shaken and broken loose from the side of the building, bearings lifted out of place..... that SOB must've been shakin' and a rattlin' to beat all.

Troy... I'll send ya pics......

[PWHoppe]

Troy... I'll send ya pics......

 ???Might not be a good idea

[dinutt]

I agree with Pwhoppe not a good idea to send pics. Cook will be getting all the media and publicity they don't need or want at this time I am sure! I can honestly say that it is possible to happen to any of the sites out there... Agree totally on what  BeerCourt says about the mess and what needs to be done.  The asbestos mess is a  pain in the b---...it is or should be  a HUGE  eye opener to start looking into this OE now and look ahead in the event of   I can only relate to my own experience and part of my job  in the event I had to respond , thankful no one got hurt....  a shame this has happened.I have worked DC Cook in the past, love the plant,people and the area is so nice.Best of luck in this recovery time.keep us updated .......

Di

[nuke_girl]

The asbestos mess is a  pain in the b---...it is or should be  a HUGE  eye opener to start looking into this OE now and look ahead

i totally agree di

also im just so glad to hear no injuries.. i have family as well as friends there in the HP dept. A big shout out to my cuz..glad youre ok bro.

Davis Besse was an eye opener as well as Fermi...in this industry, maintenance SHOULD rule the day..but in all fairness ..im not at DC Cooke and i have not been for a very long time..so i cannot say what maintenance evolutions have occured. i can say this for them..when i was there...maintenance was an everyday occurance and huge projects were always being planned.

Im anxious to see the OE on this event.