Cook U1 Turbine Problems

[Already Gone]

I'm not singling out this one plant for any particular blow-off.  I'm speaking more of the general industry trend of making the fuel cycles longer and adjusting the maintenance schedule to match.  Inspections that used to be done every single year are now being done every six to eight years - on plants that aren't getting any newer.

I'm also very concerned with the trend of trying to do patch-up maintenance on line to prevent an unplanned outage.  There really isn't any evidence that that happened here - at least none we know of for certain at this point.  We'll see.

[PWHoppe]

Nothing "Double Secret Probation" this is a release to the media. BTW don't believe everything you hear this is an essentially new turbine put in during fall of 2006

COOK UNIT 1 GENERATOR FIRE INSPECTIONS CONTINUE
BRIDGMAN, Mich., Sept. 22, 2008 – Initial indications are that Saturday night's fire at American Electric Power's (NYSE: AEP) Cook Nuclear Plant Unit 1 occurred when turbine vibrations led to a generator hydrogen leak that ignited. Damage to the turbines and generator from the fire is minimal, but vibrations did damage the low pressure turbines, bearing supports and some steam piping.
The cause of the vibrations is believed to be an imbalance from the loss of turbine rotor blades.
Hydrogen is used in a closed system to keep the generator cool during operation and the seals that contain the hydrogen were likely damaged by the vibrations.
"We know how to fix and operate equipment, but we are most gratified that there were no personal injuries as a result of the incident," said Mike Rencheck, AEP senior vice president and chief nuclear officer. "Our plant operations crews, fire brigade, security officers and other emergency responders all performed well. We are also very appreciative of the excellent response and support of local fire fighters and law enforcement."
The small fire was quickly contained by the plant fire brigade. Fire personnel from Lake Township, Bridgman, Lincoln Township, Royalton Township and Chikaming Township responded to the site or mobilized. Berrien County Sheriff's deputies and Baroda/Lake Township law enforcement also responded. 
One the plant's three fire pumps was damaged and a 12-inch water supply line broke. Cook uses Lake Township water as a back-up to on site water storage tanks and is currently connected to that system.
An estimate for returning the unit to service will be made after the turbine casings are removed and the turbines fully inspected. It is expected to take about one to three weeks to complete turbine inspections.
The generator is in the Turbine Building and is separate from the nuclear reactor that is located in the Containment Building. The nuclear systems were unaffected by the generator fire. AEP has sufficient reserve generating capacity so the loss of the Cook unit had no impact on customers. Cook Unit 2 remained at 100 percent power through the incident.

[remowil55]

DC Cook is a commercial issue, if upper management wants to risk busting a turbine to stay online and make revenue, that's their prerogative,

I have to disagree with ya on this one Marssim, Upper Management has no right to do that.

First, is personnel safety, no one has the right to risk another persons personal safety, such as the people working on the turbine deck. Had a worker been injured or killed, then it become criminal.

Second, they have no right to risk the safety of the plant, Upper Management does not own that plant.

Third, they have a inherent responsability to the local and nuclear community to operate that plant in the safest manner possible.

Fourth, see number two, shareholders own that plant.

Finally knowingly operating the plant in an unsafe condition is an NRC violation. Such as Davis Bessie was.

Finally i have seen a video of an low pressure turbine explosion and fire, i don't recall where it took place but it destroyed the turbine building and about 20 cars in the parking lot because of flying debris, the interstate runs in front of at D.C.Cook less than 1/4 a mile from the turbine deck.

The Nuclear Business doesn't need anymore black eyes because of operating ignorance. This is a Nuclear issue. Any safety, security, or radiological, maintenance failure is a Nuclear Issue.

[thenuttyneutron]

I have to disagree with ya on this one Marssim, Upper Management has no right to do that.

First, is personnel safety, no one has the right to risk another persons personal safety, such as the people working on the turbine deck. Had a worker been injured or killed, then it become criminal.

Second, they have no right to risk the safety of the plant, Upper Management does not own that plant.

Third, they have a inherent responsability to the local and nuclear community to operate that plant in the safest manner possible.

Fourth, see number two, shareholders own that plant.

Finally knowingly operating the plant in an unsafe condition is an NRC violation. Such as Davis Bessie was.

Finally i have seen a video of an low pressure turbine explosion and fire, i don't recall where it took place but it destroyed the turbine building and about 20 cars in the parking lot because of flying debris, the interstate runs in front of at D.C.Cook less than 1/4 a mile from the turbine deck.

The Nuclear Business doesn't need anymore black eyes because of operating ignorance. This is a Nuclear issue. Any safety, security, or radiological, maintenance failure is a Nuclear Issue.

I agree with this.  The loss of a turbine is a RX trip initiator.  That simple fact adds risk to the reactor.  What if there was a signifigant event from a minor system that caused a core melt problem?  Crap, there was one in 1979 and it was in Pa. 

TMI all got started with problems in the instrument air header which set off the chain of events to a core melt event.

[justatech]

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?

That was the first question we asked Monday morning and were told NO, which is the only good news.

[vikingfan]

saw some pics and boy it doesn't look good !!

[Rennhack]

Local radio station coverage:

http://wsjm.com/NRC-Says-Cook-is-Safe/3025294

Plant personell have been told not to discuss the incident - even with family.

[Melrose]

Local radio station coverage:

http://wsjm.com/NRC-Says-Cook-is-Safe/3025294

Plant personell have been told not to discuss the incident - even with family.

Funny....... the afore mentioned, "plant personnel", are the ones sending all the pictures and notifications from the PM around.  I'm sure half the country knows what happened by now.

[Rennhack]

Reuters article:

http://www.reuters.com/article/rbssIndustryMaterialsUtilitiesNews/idUSN2527572420080925

[Melrose]

Reuters article:

http://www.reuters.com/article/rbssIndustryMaterialsUtilitiesNews/idUSN2527572420080925

Wow, they "talk purtier than a two dollar whore"...... -  bastardized from slim pickens, I think

They ain't coming back online in two to three weeks.

[Rennhack]

They ain't coming back online in two to three weeks.

Thats what I was thinking...

[rlbinc]

In my humble opinion...it will take one to three weeks to return the unit to service.
After about a year of repair work.

[Rennhack]

In my humble opinion...it will take one to three weeks to return the unit to service.
After about a year of repair work.

Exactly...  They have MAJOR turbine damage.  Unless there is an extra turbine sitting around some where... it isn't happening.  - Berrings are shot, bladse thrown... heck, even the housing is damaged...

I wouldn't even buy 2-3 months.

[Laundry Man]

Housing, easy fix, cut out patch.  Finding another rotor or three, some extra diaphragms and exciter might take a little longer .
LM

[Fermi2]

In my humble opinion...it will take one to three weeks to return the unit to service.
After about a year of repair work.

I've seen the pictures and based on the very similar damage as Fermi had I'm thinking a year of work, about a month of testing.

Mike

[HydroDave63]

I've seen the pictures and based on the very similar damage as Fermi had I'm thinking a year of work, about a month of testing.

Mike

Pictures..where?

[Fermi2]

Dave,

Email me. I have a bit over a dozen. Pretty impressive.

Mike

[Already Gone]

Housing, easy fix, cut out patch.  Finding another rotor or three, some extra diaphragms and exciter might take a little longer .
LM

You haven't seen this casing.  It is more than just dents and holes.

[HydroDave63]

Casings are easy....it's getting a couple 100 ton forgings made, and new blades cut, it's a year from when your check clears. Saw this at a plant once upon a time....

[Melrose]

Pictures..where?

Dave...
Check out the Cook photo album http://www.nukeworker.com/pictures/thumbnails-120.html
someone has loaded the initial (first entry) pictures there.

[Fermi2]

Mine are lots better!

[Melrose]

Mine are lots better!

As I said... the are THE prelim photos,
I've got a disc of >50 taken after they broke into things, too many to post, ya wanna see 'em, lemme know, later

BTW
You got pictures of the brass plates that were brazed to the buckets during tuning?  How 'bout pics of the one that fell off? 

[rlbinc]

I remember teaching about trip redundancy.
Overspeed Trip has a Backup Overspeed Trip. Turbine Stop Valves and Turbine Control Valves all close off steam to the HP Turbine on a Trip, there's redundancy there.
Intermediate Stop Valves and Intercept Valves similarly close off steam to the LP Turbines on a Trip. There are Lockout Relays and Backup Lockout Relays.

One of my students asked, "What backs up the High Vibration Trip?"
The answer, "Low Bearing Oil Header Pressure Trip after the thing comes apart, and if it's bad enough, a Low Vacuum Trip, after a blade goes through the condenser or turbine hood."

The lesson: (and I don't know if they did) Folks, don't EVER bypass Turbine Supervisory Trips.

[Rennhack]

Please note, the AEP (DC Cook) legal team has requested that we do not display any pictures which relate to the recent turbine issue. 

Your assistance in this matter is appreciated. 

[Melrose]

Skeered?

just funnin'