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Three Mile Island Shuts Down After Pump Failure

samzenpus posted about 2 years ago | from the a-bit-of-a-problem dept.

Science 247

SchrodingerZ writes "The nuclear power station on Three Mile Island in Pennsylvania shut down abruptly this afternoon. Its shutdown was caused when one of four coolant pumps for a reactor failed to work. 'The Unit 1 reactor shut off automatically about 2:20 p.m., the plant's owner, Exelon Corporation, reported. There is no danger to the public, but the release of steam in the process created "a loud noise heard by nearby residents," the company said.' If radiation was released into the environment, it is so low that it thus far has not been detected. The plant is a 825-megawatt pressurized water reactor, supplying power to around 800,000 homes, thought there has been no loss of electrical service. Three Mile Island was the site of a partial nuclear meltdown in 1979. The Unit 2 reactor has not been reactivated since."

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And, cue shitstorm.. (5, Insightful)

Anonymous Coward | about 2 years ago | (#41407701)

But, to be fair, isn't this how these things are suppose to work? Something fails, everything gracefully shuts down?

Re:And, cue shitstorm.. (5, Insightful)

fredgiblet (1063752) | about 2 years ago | (#41407725)

Yes.

Not that that's going to stop the shitstorm

Re:And, cue shitstorm.. (4, Funny)

Black Parrot (19622) | about 2 years ago | (#41407805)

Yes.

Not that that's going to stop the shitstorm

Clearly, we need more backup pumps for shitstorms.

Re:And, cue shitstorm.. (1)

Anonymous Coward | about 2 years ago | (#41407833)

The internet has an infinite supply, no worries.

Re:And, cue shitstorm.. (1)

Anonymous Coward | about 2 years ago | (#41408139)

Obligatory Kingpin reference:

A huge cloud of shit? Wow! I think i smell it!
Hey everyone, there's a shit cloud coming! Run for your lives!

Re:And, cue shitstorm.. (3, Insightful)

ozmanjusri (601766) | about 2 years ago | (#41408015)

Maybe.

I'll reserve judgement on what's actually happened, because this industry has a history of salamitaktic, lying, cover-ups and manipulation of public opinion.

It's possible this innocuous announcement is the start of a series of press-releases, each admitting to progressively worse problems. If that's the case, all the Pollyannas on Slashdot will have vanished by the time the real scope of the event is clear.

Re:And, cue shitstorm.. (5, Interesting)

Anonymous Coward | about 2 years ago | (#41408079)

Oh for fucks sake. There are event classifications if shit goes really wrong. Since they didn't even declare an Unusual Event (lowest of four classifications), things are under control. It appears that there may have been complications during the trip, but there is no emergency. And for your information, if there is an emergency the plant has to declare it within 15 minutes and inform state and local authorities within another 15 minutes. The people who make these decisions are licensed by the NRC and can be held personally responsible. They are also legally protected from any type of retaliation for taking action based on safety concerns. They aren't going to cover it up for three reasons: 1) their families live nearby, 2) the legal ramifications are severe, and 3) they could easily get another job at any other plant in the country (~2000 workers of their level of training in an industry that wants 3000 or 4000).

Re:And, cue shitstorm.. (0)

Anonymous Coward | about 2 years ago | (#41408137)

buh-buh-buh..... itz nuke-yew-lur! The whirled will end! an-an-an... rad-ee-ATION! An STUFF!

Re:And, cue shitstorm.. (-1)

Anonymous Coward | about 2 years ago | (#41408219)

Which bit of "I'll reserve judgement " did you not understand, you pompous dolt?

Re:And, cue shitstorm.. (4, Informative)

Anonymous Coward | about 2 years ago | (#41408467)

"Three Mile Island is still shutdown Thursday night. Around 220 Thursday afternoon, people who live near the nuclear power plant heard a loud noise, saw steam and then the plant automatically shut down.

This is the second time that this has happened in the past month."

http://www.whptv.com/news/local/story/UPDATE-3-Thursdays-TMI-shutdown-is-the-second-in/_Z1vYirDt0ybASp0FZhmUw.cspx [whptv.com]

"The Nuclear Regulatory Commission said Thursday that it was satisfied with Exelon’s repairs following a reactor shut-down at Three Mile Island on Aug. 22.

The NRC said a small leak in the reactor coolant system was caused by “micro-cracks” in a diaphragm in a pressurized heater bundle within the containment barrier. The cracked diaphragm was made of alloy 600; it was replaced with one made of stainless steel, and the unit was powered back up."

No doubt the saga will continue.

X-men escaped. (1)

leuk_he (194174) | about 2 years ago | (#41408405)

They will never tell you one of the x-men/kids escaped. [cleanenergy4america.org] they might tell you that the invisible radiation inside has become too high , so nobody can check what really is going on.

If someone does spot something and report it, it will be mistake for fantasy.

The biggest secrets are all in the open....

Re:And, cue shitstorm.. (4, Insightful)

bcmm (768152) | about 2 years ago | (#41408645)

To be fair to the shitstorm, there are historical reasons to be a bit worried when Exelon describe something as a planned release of steam with minimal release of radioactive material. Lets hold out for the NRC report.

Re:And, cue shitstorm.. (3, Interesting)

Anonymous Coward | about 2 years ago | (#41407861)

Yep. Basically, everything worked as it was meant to. Problem will be fixed soon and life will continue as usual.
Also, if one wishes to scare greenies half to death: http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2012/ [nrc.gov]

Re:And, cue shitstorm.. (5, Interesting)

Anonymous Coward | about 2 years ago | (#41407945)

It doesn't sound like a graceful shutdown. We'll have to wait for the NRC event report tomorrow. A reactor cooling pump trip would typically initiate a reactor protection trip (scram). The steam generators would cool the primary by sending steam to the condenser steam dumps. Instead there was a loud noise which indicates that steam was being vented to the atmosphere via the atmospheric steam dumps. This implies that the main steam stops (isolation valves to the turbines) shut. Potential causes for that would be excessive cooldown (an interlock), loss of the condenser vacuum, or a secondary equipment fault. None of these is normal.

I'm guessing that it was probably an electrical fault. A reactor cooling pump trip and secondary pumps could be powered from the same electrical buses since they are not considered safeguards equipment. The other possibility is that the operators didn't control the cooldown properly, or there was an I&C fault that tripped an interlock for the main steam isolation valves.

Disclaimer: I'm familiar with Westinghouse PWRs, but not the Babcock & Wilcox PWRs. So take what I say with a grain of salt.

Re:And, cue shitstorm.. (1)

Splab (574204) | about 2 years ago | (#41408297)

Would that be rock salt? Perhaps Thorium?

Re:And, cue shitstorm.. (4, Funny)

TheLink (130905) | about 2 years ago | (#41408321)

Nah potassium iodide, 130mg.

Re:And, cue shitstorm.. (-1)

Anonymous Coward | about 2 years ago | (#41408305)

Hate to burst your bubble but I would not trust what the NRC has to say over this incident. They will make up some BS, you should be part of a public watchdog reporting this it seems to be accurate unlike the NRC. The plant is how old now? I guessing these things happen all the time with the other older reactors throughout the country, some failure due to aging equipment.

Re:And, cue shitstorm.. (4, Informative)

thegarbz (1787294) | about 2 years ago | (#41408443)

Of course it's not graceful but a shutdown as a result of equipment failure never is. Steam venting isn't graceful, but then neither is a SCRAM.

I work in the process industry and the only time a shutdown is ever graceful is through carefully planned and usually long duration operator actions. Even then some processes they just get it down to a stage where there will be minimal damage and then hit the trip button and hope nothing breaks.

The key thing here is what shutdown the process was a safety system which prevented a hazardous event from occurring, rather than hazardous event occurring and causing the shutdown. Compared to that this event really can be considered quite graceful.

Re:And, cue shitstorm.. (4, Interesting)

dbIII (701233) | about 2 years ago | (#41408479)

It doesn't sound like a graceful shutdown

A "graceful" emergency shutdown of a large thermal power station unit is actually bloody noisy as the steam goes into the blow down vessel/s.
Also any water that touches the turbines doesn't actually go into the reactor, it goes through heat exchangers where the working fluid of the reactor is on the other side.
Disclaimer: I'm familiar with the turbine side (fairly universal amoong all thermal power stations of the same size) but in my case the boilers were all coal fired. There are many similarities to the point where one of my co-workers was a Russian turbine engineer with a lot of nuke experience (and some scary stories).

Re:And, cue shitstorm.. (5, Informative)

Anonymous Coward | about 2 years ago | (#41408565)

This is a very accurate reply with one exception. Generally, the condenser can't support the steam output of the steam generators (they're normally rated around 10-25% of full load). Most plants in the US will steam dump to atmosphere because it's easier and doesn't put unnecessary strain on the equipment.

Plus, dumping to atmosphere has the added benefit is that the whole plant staff knows immediately that they are staying late.

Source: I am an I&C engineer that has worked on many US and European units.

Re:And, cue shitstorm.. (3, Informative)

Anonymous Coward | about 2 years ago | (#41408115)

Um, no. This is how these things are supposed to fail.

Re:And, cue shitstorm.. (2)

Chrisq (894406) | about 2 years ago | (#41408543)

Um, no. This is how these things are supposed to fail.

I don't know why this is modded down - its absolutely correct. Nuclear reactors are designed to be "fail safe". If a pump breaks, the system shuts down. There are probably backup pumps in case the shutdown fails too, etc.

Re:And, cue shitstorm.. (1)

AHuxley (892839) | about 2 years ago | (#41408167)

From the 1960s and 1970s, ~40 years, but dont worry they many in the US got a rubber stamp extension :)
20-year extensions where granted, so expect to see 80 years, and then 100.
The designed for a duty cycle is now a historical number, a better understanding of earthquakes and flooding is put to one side.
The sub systems are also an interesting risk, you can have a great reactor, lots of diesel ready, good protected diesel generators, extra staff on site after they all get called back in - if the cooling systems for the massive diesel units fail nothing is really ready... the full backup system has to work every time..
With age this all gets more complex. Parts fail, a better understanding of the structures and movement under the plant...
Direct inspection is another area that can be interesting ie fall apart and thinning of metal vs paperwork.
New parts are also showing interesting signs of been in need of more inspections very early in their life - ie who pays to replace a brand new upgrade as it thins at a very rapid rate?
http://www.ocregister.com/news/unit-338565-reactor-plant.html [ocregister.com]

Re:And, cue shitstorm.. (1)

Anonymous Coward | about 2 years ago | (#41408259)

But, to be fair, isn't this how these things are suppose to work? Something fails, everything gracefully shuts down?

Which won't stop every envirowhack on slashdot from waving his hankie and screaming "NUKLYUR EVIL!!".

Re:And, cue shitstorm.. (1, Troll)

tehcyder (746570) | about 2 years ago | (#41408727)

But, to be fair, isn't this how these things are suppose to work? Something fails, everything gracefully shuts down?

Which won't stop every envirowhack on slashdot from waving his hankie and screaming "NUKLYUR EVIL!!".

It's not nuclear power that is evil, it's the fuckwads who end up working there and/or in charge of it. My father used to work in nuclear power stations, and he said once that the opening credits of The Simpsons are closer to reality than most people would like to think.

I'm sorry, but with the nuclear power industry, it's always jam tomorrow. It needs to be tightly controlled by people with no vested financial interest in it, but of course that is too fucking socialist for everyone nowadays.

Re:And, cue shitstorm.. (0)

Anonymous Coward | about 2 years ago | (#41408687)

Emergency steam vent to atmosphere is not graceful. Such venting is last resort before rupture. In any steam system other things should have happened before such venting but did not.

Three Mile Island is STILL open?!?!?! (1)

Anonymous Coward | about 2 years ago | (#41407711)

I for one welcome our new glow-in-the-dark overlords.

Re:Three Mile Island is STILL open?!?!?! (1, Troll)

fredgiblet (1063752) | about 2 years ago | (#41407735)

Implying Three Mile Island was even a big deal.

Re:Three Mile Island is STILL open?!?!?! (2, Interesting)

dbIII (701233) | about 2 years ago | (#41408513)

It was a huge deal. A plant with a control system that wouldn't even pass regulations at a fertilizer works showed that you couldn't play fast and loose with nukes just because there were no regs to prevent you doing so, so that meant improvement of some other plants, shutting down some absolute deathtraps of the 50s and 60s, and a move towards better designs.

Re:Three Mile Island is STILL open?!?!?! (4, Insightful)

tehcyder (746570) | about 2 years ago | (#41408749)

Implying Three Mile Island was even a big deal.

If this was a fucking software discussion I'd be calling you a paid shill for the nuclear power industry now and getting modded up for it.

But as the slashdot groupthink is that anyone who is not 100% a cheerleader for nuclear power is some tree-hugging commie, we all know what will happen.

Re:Three Mile Island is STILL open?!?!?! (1)

sjames (1099) | about 2 years ago | (#41407767)

Yes, TMI-1 is running just fine and has been ever since we figured out what happened to TMI-2 and how to not have it happen again.

Yep, and now (0)

Anonymous Coward | about 2 years ago | (#41407845)

And today the same thing will happen again. We will discover the problem and it will not happen again.

Re:Three Mile Island is STILL open?!?!?! (1)

petermgreen (876956) | about 2 years ago | (#41407779)

Due to a combination of nimbyism and practical considerations it's very common to have multiple reactors at one site.

TMI-2 was where the famous accident happens and was shut down permanently due to massive internal radioactive contamination. Afaict TMI-1 has had minor incidents over the years but nothing that would require a permanent shutdown.

Re:Three Mile Island is STILL open?!?!?! (4, Interesting)

quenda (644621) | about 2 years ago | (#41407901)

Why not? You might be surprised to hear that the Chernobyl power station operated until 2000, 16 years after the well known incident.

Fukishima may not do so well. Losing a single reactor, as the US and USSR did, may be seen as bad luck. Losing three of them is an embarassment.

Re:Three Mile Island is STILL open?!?!?! (0)

Anonymous Coward | about 2 years ago | (#41408119)

They'll fire up Fukushima 5 and 6 again. Just you watch. Yes, I know the Japanese are supposedly abandoning nukes. I also know they're going into a debt crises, have become net importers and sometime in the next 10 years they will stop indulging idiocy and put the nukes back on line.

Re:Three Mile Island is STILL open?!?!?! (1)

c0lo (1497653) | about 2 years ago | (#41408173)

I also know they're going into a debt crises, ...

Well... it's not like US have a monopoly on QE - Japan is at its eight [telegraph.co.uk] already.

soggy hand luke (1)

Anonymous Coward | about 2 years ago | (#41407769)

why not power an island with the furious masturbation of basement dwellers?

Some one in 7G messed up (4, Funny)

Joe_Dragon (2206452) | about 2 years ago | (#41407785)

Some one in 7G messed up

Re:Some one in 7G messed up (1)

nihilistcanada (698105) | about 2 years ago | (#41407815)

If only Frank Grimes had lived, none of this would have ever happened.

Re:Some one in 7G messed up (1, Funny)

Anonymous Coward | about 2 years ago | (#41408591)

Hmm... Nuclear power mishap? Pennsylvania? Sounds like its time for my comic book featuring an atomic Amish super team. Send in the X-Menonites!

Granted I doubt Three Mile is near any Anabaptist communities, and Menonite is different from Amish. But I'd pay to see that book.

Add it all up (5, Insightful)

medcalf (68293) | about 2 years ago | (#41407793)

Embassy attacks. Crap economy. Foreign policy humiliation. Three Mile Island. Am I the only one who didn't like 1979 the first time, and don't want a replay?

Re:Add it all up (1)

arkane1234 (457605) | about 2 years ago | (#41407863)

We did not have a recession starting more than 4 years before 1979... at least we've exceeded our failures in that respect.

Re:Add it all up (-1)

Anonymous Coward | about 2 years ago | (#41408197)

Tell that to Chrysler.
http://en.wikipedia.org/wiki/1973_oil_crisis [wikipedia.org]

Hell, almost the entire 1974 Chevrolet line was just the 1973 models with an extra badge stuck above the grille, because GM was _desperately_ shifting resources to try to match the sudden swing in the once-reliable consumer purchasing pattern. The oil crisis kicked off a big mult-year shakeup and shakedown of the economy. Many areas went into full recession. I lived in one.

And in 1979 along with the other listed woes we got the "Chrysler Corporation Loan Guarantee Act of 1979" bailout.

Re:Add it all up (1)

Splab (574204) | about 2 years ago | (#41408325)

Yes! Always strive to improve!

Re:Add it all up (0)

BitZtream (692029) | about 2 years ago | (#41407921)

Perhaps you should stop overreacting as neither now nor 1979 were really 'bad' by any real sense of the word. Perhaps 'bad' to a spoiled American (I'm American as well) but not bad to anyone who actually has to fight to survive in some 3rd world country.

Re:Add it all up (1)

Anonymous Coward | about 2 years ago | (#41407995)

It takes a Jimmy Carter to get a Ronald Reagan.

Just sayin.

Re:Add it all up (1)

treymd (757333) | about 2 years ago | (#41408067)

This is not a Carte-Reagan election. Unlike Carter, Obama did nothing prior, during, and likely after his term, and Mitt Romney is a terrible actor.

Re:Add it all up (-1)

Anonymous Coward | about 2 years ago | (#41408665)

Ronald Reagan was also a terrible actor.

Re:Add it all up (0)

tehcyder (746570) | about 2 years ago | (#41408779)

Ronald Reagan was also a terrible actor.

As well as being a terrible politician and a truly evil president.

Re:Add it all up (-1, Flamebait)

tehcyder (746570) | about 2 years ago | (#41408783)

It takes a Jimmy Carter to get a Ronald Reagan.

Just sayin.

I'd rather have Jimmy Carter than Ronald McDonald Reagan any day of the week. It wasn't Carter's fault that your fabulous US military fucked up the Iran hostage thing.

Re:Add it all up (1)

Anonymous Coward | about 2 years ago | (#41408081)

Let's hope we get something as good as The Wall again this time.

Re:Add it all up (0)

Anonymous Coward | about 2 years ago | (#41408201)

I was born in '79, what's not to like? ..oh a quick google says: 'everything'.

Sorry mate.

Re:Add it all up (4, Funny)

tehcyder (746570) | about 2 years ago | (#41408759)

At least the music was better back then. Now get off my lawn.

Move along... (1)

gubon13 (2695335) | about 2 years ago | (#41407801)

...nothing to see here...

No redundancy (1)

treymd (757333) | about 2 years ago | (#41407803)

Can they not have parallel backup pumps designed to leap into action when needed? Seems like some extra plumbing and monitoring hardware could help avert a costly shutdown.

Re:No redundancy (1)

corsec67 (627446) | about 2 years ago | (#41407819)

But then what about the reliability of that backup hardware, especially if it isn't subject to the same kinds of loads as the primary?

At a certain point, "Shut everything down (safely)" is cheaper than having more redundant valvles, pumps, pipes, and more tubes in a series.

It is like RAID 1: you are more likely to have some kind of hard drive failure, but that hard drive failure is more likely to be recoverable.

Re:No redundancy (0)

Anonymous Coward | about 2 years ago | (#41407835)

Possibly depends on the nature of the system. There would be times you don't want it to automatically switch over, as you don't know if the pump failure was from the pump itself, or a problem someplace that would be common to multiple pumps, e.g. a damaged or blocked cooling line. It is just like how you can get circuit breakers that automatically reset after tripping... potentially bad if what tripped it before is going to get worse by reseting, although there are expensive that will try to reset when they are sure it can handle a few tries even with bad faults.

Re:No redundancy (1)

tangent3 (449222) | about 2 years ago | (#41407847)

Says right there: "Its shutdown was caused when one of four coolant pumps for a reactor failed to work."

Could probably have continued operating on the remaining 3 pumps, but was shut down for safety.

Re:No redundancy (1)

treymd (757333) | about 2 years ago | (#41407885)

That to me implies that the normal situation is that all 4 pumps must be running, and they are not there for redundancy at all. If not, why have the other 3 pumps there at all?

Re:No redundancy (1)

fragMasterFlash (989911) | about 2 years ago | (#41407943)

That to me implies that the normal situation is that all 4 pumps must be running, and they are not there for redundancy at all. If not, why have the other 3 pumps there at all?

The answer to that question changed considerably when the Fukushima incident occurred. The entire nuclear power industry is held accountable for the failings of even the most reckless of its ranks.

Re:No redundancy (0)

Anonymous Coward | about 2 years ago | (#41407957)

Because it's a nuclear reactor? If it can work with two, you'll have four, and shutdown the instant one of them has problems.

Re:No redundancy (2)

treymd (757333) | about 2 years ago | (#41407993)

The fact that it is a nuclear reactor means that it SHOULD have backups, and backups for those backups, and if that should fail, there is a backup for that. Perhaps NASA should run our nuclear power plants.

Re:No redundancy (1)

Anonymous Coward | about 2 years ago | (#41408385)

It does, but for safety reasons the backups only run until the reactor can shut down.

Would you expect to run your servers as normal on UPS power, or would you use that power to effect a clean shutdown so you don't have problems when power is restored? It's exactly the same principle.

Re:No redundancy (5, Informative)

sjames (1099) | about 2 years ago | (#41407973)

They ARE there for redundancy. For safety reasons, a reactor must not be operated without adequate redundancy. So, one of the redundant pumps failed and the system shut down in an orderly manner. That is necessary since it takes just a wee bit longer to swap in a cold spare pump than it does for a disk in a RAID.

It would be technically possible to run the reactor on 3 pumps but safety would be compromised.

The best way to know a pump will run is to have it running. That's why they keep all 4 running under normal conditions.

Re:No redundancy (2)

treymd (757333) | about 2 years ago | (#41408017)

That is actually sort of alarming to me since they probably install 4 identical pumps at the same time each with a rated lifetime that is about the same. So when the first fails, the others are surely soon to follow, And that takes us full circle to why if one fails, the system is designed to shut down.

Re:No redundancy (1)

sjames (1099) | about 2 years ago | (#41408151)

It's not THAT scary. Even assuming the pumps are all made exactly the same (I don't know that they are), failing 'at the same time' would mean within a year or two of each other.

I'm guessing (but it's a good guess) that one pump could manage when it has scramed.

Re:No redundancy (0)

Anonymous Coward | about 2 years ago | (#41408231)

Not if they run them at different intensities or don't run all the pumps all the time. For example they might power up the back-up pump every day for an hour to make sure it still works. Or they might run it all the time but only put it at full power for an hour a day.

Re:No redundancy (1)

koxkoxkox (879667) | about 2 years ago | (#41408327)

You are right and I sure hope they are running like GP says they are. If you have backup pumps, of course you do not run them like the others. You shouldn't forget about them for twenty years hoping they will just wake up when needed, but running them full-time would be nuts.

Re:No redundancy (1)

omglolbah (731566) | about 2 years ago | (#41408715)

You do not wait for the pumps to hit the rated lifetime... You replace them in a revision/maintenance stop with time to spare.
If a pump fails you determine why, and if it is warranted replace it.

Re:No redundancy (-1)

Anonymous Coward | about 2 years ago | (#41408711)

Emergency steam venting means it was not orderly. The venting is the last resort. Boilermen or engineers can be fired over such venting as it is likely due to negligence or incompetence. Maintenance or operation of the pressure system is likely where some inadequacy will be found.

Re:No redundancy (0)

Anonymous Coward | about 2 years ago | (#41408741)

Unexpected things happen when components fail. News at eleven.

Re:No redundancy (1)

thegarbz (1787294) | about 2 years ago | (#41408463)

Not just in nuclear but in the process industry in general to meet certain risk reduction goals for process safety redundancy is not enough. Redundancy can have failures and the failures require actions to be performed. The way this is typically done is when a piece of equipment has a failure in one of it's areas (say a safety PLC loses a processor card) a countdown timer starts to automated shutdown.

I look forward to seeing the full report on this.

Re:No redundancy (1)

Anonymous Coward | about 2 years ago | (#41408677)

no different than a four engine airplane, if you lose an engine it will fly just fine but you would still make a safety landing

Re:No redundancy (1)

Osgeld (1900440) | about 2 years ago | (#41407867)

I would rather it shut down than have some pump and plumbing that hasnt been used since the 70's at random take the full force at any given time

but hey you go right ahead

Re:No redundancy (1)

treymd (757333) | about 2 years ago | (#41407893)

I would say routing testing and replacement would make this a non issue, but egghead corner cutters tend to think this is the place to cut corners, so I am inclined to agree.

Re:No redundancy (1)

Osgeld (1900440) | about 2 years ago | (#41407937)

that and temporary testing is not a real measurement of long term performance

great it passed the 10 hour test, hows that going to hold when its the only path for a week?

Re:No redundancy (1)

treymd (757333) | about 2 years ago | (#41407985)

If the backup fails then the system shuts down. as intended.

Re:No redundancy (0)

Anonymous Coward | about 2 years ago | (#41407891)

Primary coolant pumps that work at 150 atmospheres aren't exactly cheap and you sure as hell can't hot-swap them, having a spare primary coolant loop would also give another possible point of failure. The unit probably could function with 3 pumps but for safety reasons they wouldn't risk it.

I can't think of any other industry where an equipment failure that leads to nothing but some downtime and expense for the company makes the headlines. Please /. stop reporting non-news.

Re:No redundancy (2)

quenda (644621) | about 2 years ago | (#41408007)

They do have redundancy. The power station is connected by a grid to other power stations.
Normally they also have multiple reactors at one site, but for some reason TMI #2 has had an extended outage.

Re:No redundancy (2)

treymd (757333) | about 2 years ago | (#41408031)

I believe it was stated that #2 is so polluted that it is on permanent shutdown.

Re:No redundancy (1)

jamesh (87723) | about 2 years ago | (#41408021)

Parkinson [wikipedia.org] obviously hadn't imagined Slashdot when he proposed his Law of Triviality...

Re:No redundancy (0)

Anonymous Coward | about 2 years ago | (#41408075)

Having parallel pumps is very expensive. You can't just leave them alone, you've gotta test them all the time. Testing is regularly without causing brownouts is probably very difficult.

And it would only protect you from pump failure. There would still be other types of failure that can bring the system offline.

So, instead of parallel pumps, they just have enough power stations in other places to cover any individual station going offline.

Re:No redundancy (1)

Gordonjcp (186804) | about 2 years ago | (#41408233)

What happens when the cutover from one system to the backup system fails? How do you avoid a single point of failure? Yes, you could run both pumps in parallel at half power and devise some means of shutting off a failed pump and running the other at full power. That *still* introduces more complexity and more potential failures.

It's like they say about twin-engine aircraft - if one engine goes, the other has enough power to fly you right to where the crash happens.

Re:No redundancy (1, Informative)

Anonymous Coward | about 2 years ago | (#41408269)

Reactors run with 'inoperable' components all the time. Primary Reactor Coolant Pumps [frbiz.com] aren't one of them. They circulate core coolant in high volumes and they literally cost a fortune. When a PRCP trips you SCRAM, cool the core and figure out the problem. No fucking around. When you've figured it out the chairman of the NRC and the CEO of your power company is briefed.

There are four on that particular reactor, btw. All four must be 100% for the reactor to be allowed to operate.

I would love to be there once during a SCRAM. When a PORV on a B&W PWR lifts at full power the noise is heard for miles. A primal howl of super heated steam blowing out of the reactor. Every mope in earshot gets reminded of exactly what it is that makes that air conditioner spin.

The valve in question is that same one that stuck open leading to a Loss Of Coolant Accident in '79. It can only be actuated like 40 times. Nuclear reactors defy everyday experience; it's best if you don't indulge too much guesswork.

sux4them (0)

Anonymous Coward | about 2 years ago | (#41407905)

glad i don't know next to a radiation spewing nuclear power plant LOL http://www.youtube.com/watch?v=5K4_uHlTcTM

Re:sux4them (1)

MobileTatsu-NJG (946591) | about 2 years ago | (#41408235)

I think I get what you're saying, but I had to set Babelfish to 'youtube' to get a decent translation

Right... (1)

lightknight (213164) | about 2 years ago | (#41407919)

Nice shutdown, but I still think we need to move to more powerful passive safety devices. Using water as a coolant is awesome, but still prone to failure. Solid conduction, on the other hand...

Re:Right... (1)

jamstar7 (694492) | about 2 years ago | (#41407967)

TMI is ancient technology. Nobody's built one of these things since TMI went online. They built using newer safer designs.

Of course, getting authorisation to shut down, decommission, and dismantle a reactor takes almost as much time, effort, legal fees, and money as building the damned thing in the first place. It's on the order of 4 acts of $DIETY and an act of Congress.

They posted a shot of the incident (2)

Grayhand (2610049) | about 2 years ago | (#41408087)

Re:They posted a shot of the incident (0)

Anonymous Coward | about 2 years ago | (#41408125)

Has anyone noticed that the spiral path of the laserbeam does not take into account the acceleration of the falling head due to gravity? The curves are perfectly parallel to each other, while they should actually stretch out in distance during the free fall.

Re:They posted a shot of the incident (0)

Anonymous Coward | about 2 years ago | (#41408319)

Has anyone not?

I'ze so skaird (0)

Anonymous Coward | about 2 years ago | (#41408103)

I was so scared until I recalled that more people died at Chappaquiddick than at Three Mile Island.

Re:I'ze so skaird (0)

Anonymous Coward | about 2 years ago | (#41408187)

That is one way to look at it. The way I see it, half the people that potentially could have died at Chappaquiddick, died. If the same percentage die at Three Mile Island, it would be catastrophic. You should be *very* afraid.
 
PS: Stupid comments deserve stupid responses.

Didn't even cause a blip (0)

Animats (122034) | about 2 years ago | (#41408229)

They had a reactor trip. Big deal. It didn't even show up as a power grid event that required emergency action in the PJM dashboard.

Welcome back Carter (1)

AntiBasic (83586) | about 2 years ago | (#41408381)

It's like 1979 all over again. I told you Carter would be a best case scenario for Obaaaaama

what even is (1)

nimbius (983462) | about 2 years ago | (#41408391)

the nuclear regulatory comission? ill wait on the IAEA, thank you...

er, wait...the IAEA doesnt investigate reactor faults in the United States. Because apparently american reactors just work.

"news worthiness"? (1)

SimplexBang (2685909) | about 2 years ago | (#41408395)

Are nuclear installation incidents the only subject that has the validity of its "news worthiness'' discussed ? Is there an inverse proportionality rule that states that the small news shouldn't concern itself with larger problem areas ? Oh boy , we have a solar eclipse , big deal , nothing to see here ?

Re:"news worthiness"? (0)

Anonymous Coward | about 2 years ago | (#41408473)

"news worthiness" = can you instill fear, doubt or anger in your audience?

'If radiation was released'? (2, Funny)

Anonymous Coward | about 2 years ago | (#41408525)

What is this? Come on America -are you turning into a load of cheese-eating surrender monkeys? The US should take pride in releasing the best and biggest cloud of radiation money can buy.

So how does that change nameplate efficiency? (0)

Anonymous Coward | about 2 years ago | (#41408571)

If unit 2 has been down since 79, that's GOT to be a large drop in the nameplace capacity.

I guess nuclear isn't reliable and you need more than nameplace power to use it...

Just like wind.

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