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Reactor Shutdown Darkens South Florida
grassy_knoll asks, "So how fragile is the electrical grid, and just what technical problems could shut down five reactors?" "Five reactors at a nuclear power plant in Florida had gone down on Tuesday and two were now back online amid a massive power outage in the southern state, CNN reported. The report on the Turkey Point nuclear plant came as four million people had lost electricity in Miami and elsewhere in Florida, with traffic signals out and major delays on roads, authorities and media said."
I hear the problem originated with a drone in sector 7-G.
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good thing I backup IP over carrier pigeon.
Here is FPL's page on the Turkey Point reactor: About Turkey Point. Their site also has a News Releases page, which I'll be watching for updates whenever they get their PR department in gear.
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Oh, wait. This is Florida. Things already look like a Mad Max movie, minus Tina Turner and with a lot more cubans.
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your ideas are intriguing and i would like to subscribe to your newsletter.
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Is this the MPAA? Is this the RIAA? Is this the DMCA? I thought it was the USA!
Uh.. Turkey Point has *2* reactors and 3 major fossil fuel generators (As well as several generators under 5 MWs).
The power outage -- ie, some serious switch failures -- triggered the reactor shutdown. Nuclear reactors are great at supplying base load power but if all of a sudden the grid goes offline, they have nowhere to send that power and have to shut themselves down. (Power reactors don't do well with highly dynamic loads.)
It was not, as some posters seem to have misread even the summary, that the reactors went down first and caused the outage. Mind, once the reactors are down it takes longer to bring the whole grid back up, so in that sense it's contributory.
-- Alastair
... at least given how much crime shows draw on real life events, albeit massively embellished. Cue Horatio Caine.. 'Looks like someone's been left in the dark.. permanently.' *removes sunglasses*
The article says that a switch caused the power outage; if the transmission lines get shut off (perhaps the switch caused a cascading failure, as has happened before), of course power plants (no matter what type) will shut down --- there's nowhere for the power to go!
The system detected there was a problem and automatically shut the reactors down; The system worked! Maybe massive blackouts aren't the best result, but they are by far better than the worst result.
Demented But Determined.
Did anybody seem to notice that while yes, the nuclear plants shut down, so did the coal plants. Neither of of the plants had problems. It was a problem with the substation.http://money.cnn.com/news/newsfeeds/articles/djf500/200802261723DOWJONESDJONLINE000845_FORTUNE5.htm
Agreed. I found the NRC press release in about 2 seconds by simply going to their website. Perhaps people should 2 seconds of research before they begin jumping to conclusions about things.
http://www.nrc.gov/reading-rm/doc-collections/news/2008/08-037.html
(NPR is running a story on it right now):
These plants were designed to shut down in case of a fall in the power reaching them from *other sources* (because they need, e.g., to run cooling pumps for a safe shutdown and can't count on their own power). I'm not sure why the outside power browned out, but it did, so these plants did what they were designed to do.
What would it take to trigger the automatic release of the control rods? An earth tremor above a pre-set limit, insufficient input of cooling water from rivers (or water that's too hot or too impure), a controller hitting the wrong switch, a software glitch, a glitch in a clock crystal screwing with timing calculations, a loose connector, a chip in an old-style spring-based socket catapulting itself into the air (which they had a nasty habit of doing), erronious control signals from other power stations, a downed power line on any segment with single points of failure, etc.
Of these, the vast majority apply to any power station - one line down not too long ago caused a blackout that covered three States and half of Canada. One line down between the east and west coasts about 14-15 years ago shut down large parts of the northwest USA for a couple of weeks. Cascading failures are inherent in the meta-stable mashup of networks that form the power grid. Too many SPFs, too little redundancy, too many communication glitches, too few contingency plans.
Personally, I think the grid needs to be massively redesigned, with far better (and more intelligent) signalling, far more redundancy at all levels and a huge upgrade on software and hardware (NT4 and Windows 3.11 are not acceptable to me for mission-critical systems - they're tried and tested, but they're not reliable and they're not secure).
Of course, this won't happen, massive cascading faults will continue to be reported on a regular basis, and people will continue to be surprised when they occur. Preventative maintenance on the scale needed to cure the system as a system is so expensive (even though it's one-off), the distributed costs of regular blackouts on even a gigantic scale look cheaper on the balace sheet, so an inefficient, decrepid, flawed power grid becomes the preferred option.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
It was due to a distribution line that failed. For those not familiar with how nuclear reactors work, two of the fission products of concern are I-135 and Xe-135. I-135 will decay into Xe-135 and Xe-135 is a very strong neutron poison (absorbs neutrons). During normal operations Xe-135 is produced from fission or I-135 decay and it is removed by neutron absorption of Xe-135 or by beta decay of Xe-135. If you are operating at high power and have a significant amount of Xe-135 in the core and you suddenly drop power the neutron flux that is removing a significant fraction of your Xe-135 from neutron absorption is gone. But the I-135 in the core still remains and more than compensate the reduction of Xe-135 from direct fission. The result is a Xe-135 spike that will overwhelm certain types of reactors forcing a shutdown and a waiting period for the Xe-135 to decay. For those familiar with the Chernobyl disaster, the reason that the control rods in that core were fully withdrawn was because they were trying to compensate for a xenon transient (since they were operating at high power before they dropped to low power for the test). The Turkey Point reactors don't suffer from the flaws that the RBMKs had, but they will still be shutdown due to xenon transients.
I was on campus completely oblivious that anything happened. My girlfriend called me six times in a row, and while I had the phone on vibrate as to not to disturb the interesting lecture on the horribly long lab I'm going to have next week, I was irritated and concerned. I called her after class to see what's up, and that's when I found out there was an outage. The science and engineering side have nice generators, hence my ignorance. The building my girlfriend, Cooper Hall, is a death trap. Apparently, the idiots at USF made sure that when the electricity is out, people are actually locked inside the building. All of the doors were locked from the inside. What the hell would happen if there's a fire? I understand that's the inferior side of campus, but there are people in my phonebook over there and therefore I'm concerned!
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Actually, I believe they shutdown due to a safety issue. When they lose grid power for powering water cooling pumps etc, their standard response is to shutdown for safety reasons. Yes I know, a power generating plant that gets power off the grid, but consider if the plant is unable to drive a turbine to power its own pumps, where does it get the power from? Okay backup generators, but they can also fail. From what I hear the current dropped enough from the grid to cause them to need to shutdown the reactors. This is a good safety thing. The bad thing is the issues on the grid that caused this and other sites to shutdown generation.
And now, we return you to regular scheduled blackout... if this were an actual emergency, you would of killed the person sitting next to you.
Tes
I smell something fivey .... the Pentagon!
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If a job's not worth doing, it's not worth doing right.
What I've heard on the radio so far (in Tallahassee, FL) is that the nuclear reactors have their coolant pumps connected to the grid so if the reactor ever had to be shut down the coolant would continue to flow, avoiding a meltdown. There was apparently a problem with the substation supplying (backup) power to the coolant pumps, and as a precaution the entire reactor shut down automatically.
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More information Here (pg 34) and here
Perhaps people should 2 seconds of research before they begin jumping to conclusions about things.
You're obviously new here...
"Every great cause begins as a movement, becomes a business, and eventually degenerates into a racket." -- Eric Hoffer
1998: "A massive power outage left millions of people without power Friday. The cause of the blackout is unclear."
2008: "A massive power outage left millions of people without power Friday. The government says terrorism was not involved, but the cause of the blackout is unclear."
Sigh . . .
I'd love to see the two of them in a debate with each other. That'd be great. Think of the drinking games you could create off that.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
I'd be a little scared of the vortex of intense stupidity that would form as these two approached each other. I mean, this would probably rip quarks from each other, rip space time and bring the dinosaurs back. I think, in the interest of galactic peace that these two be kept a minimum of two hundred miles apart.
The world's burning. Moped Jesus spotted on I50. Details at 11.
I'm afraid that can't be correct. He was "imprisoned forever by a force field powered by an eternal battery" and is thus incapable of making visits to Earth, even transiently.
... wait ... xeon transients - never mind
Oh
A substation. Not the reactor. Then the reactor went offline because of the undervoltage condition caused by that power outage. Neutron-absorbers in the fuel had *nothing* to do with this.
The backup generators have backups. All critical systems have at least double redundancy, that's why nuke plants are so darn expensive to build.
Naw, if anything it would take the form of a smug cloud, which isn't quite as impressive as ripping space time -- though no less deadly.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
The reactor shut down due to the no load condition. And they can't start it up for several hours due to xenon preclusion. If they didn't shut down the reactor it would have shut itself down due to the large xenon transient. This is common knowledge for nuclear engineers. If you lose your load on a nuclear reactor, you must shut down due to the massive xenon transient. If you are not familiar with this then you should read the reactor fundamentals handbook link above. This isn't rocket science.
Most everything's been covered here, but I'll put my two cents in as a Nuclear Engineer (albeit in PA). Nuclear power plants run all safety systems on offsite power. This is a perfectly understandable setup, because if something goes wrong and we need to scram the reactor, the safety systems need to keep running. At my plant, we have two completely separate backup diesel generators to supply power in the event of loss of offsite power, but shutdown is nevertheless the automatic response, both because the diesels won't run forever and because a sudden loss of load messes with a very delicate balance of turbine power, reactor power, and load. Nuclear power is a popular black sheep for these kinds of events because people are afraid of it, and the news media profits from sensationalist broadcasting. Whatever garners the greatest response, they'll run with it. As for the grid as a whole, it is not a Florida problem. The same issue came up with that massive northeast blackout in what was it, 2003? The whole system is ancient, but it's too expensive to completely overhaul it, not to mention people wouldn't stand for the loss of power as systems were replaced and/or updated. In terms of power distribution, there's a delicate balance as plants come on and offline and demand goes up and down. Any significant transients (like this undervoltage line) just causes a complete mess. This is a problem that's only going to get worse as power demands continue to rise, especially if we don't build enough plants to keep a healthy amount of excess capacity.
I'm in Miami and experienced the horrific even (playing tennis for 45 minutes because I could not log into wow). I spoke to my bud in FPL (ze power company) and he told me that a massive transmission cable went down by aligator alley (I75 stretch that crosses the everglades). This created some load issues and a plant (non nuke) had to shut down to protect itself. This in turn routed more power to the rest of the grid creating the same effect we saw in California and in the NE in the past. Turkey Point, the nuke, was merely one of the plants that shut down to protect itself. Only reason we are talking about that one and not the others is that talking about nuclear power is sexy.
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Exactly. The FIRST time you sync a new generator to the grid, that can get a little hairy, because you've got to get the phases checked to make sure their rotation matches with the phase rotation on the rest of the grid. But once you've got phase match, with modern sync check relays and automatic syncing and switching it's pretty routine.
Now...back in the day, before modern digital relays, when you had to watch a rotating needle on a dial and the three blinking lights, and the sync check relay was an electromechanical device, yeah, it could get a little hairy to switch a generator onto the grid.
"nuclear power plant operation isn't rocket science"
- and that's why we don't have regular interplanetary space flight
"the large and rapid build-up of additional Xenon reactivity load following a reactor trip can cause an extended (approximately 40 hours) reactor shutdown"
http://www.nuceng.ca/ep6p3/class/Module3D_XenonJun21.pdf
You know all too often I hear of IP over Carrier Pidgeon as the next generation of internet technology, something even bigger than Web 2.0 and software as a service. I'm sure it's going to actualize our paradigm shifts and all that but seriously lets get some cold hard FACTS into the discussion.
Firstly:
Where are the numbers on latency and bandwidth?
Details like this are frequently brushed aside when making unrealistic promises. Let's stop listening to the marketing department and talk to the engineers working specifically with IP over Carrier Pidgeon and IP over Avian Carrier in general. (From here on referred to as IPoAC) We have no hard numbers on packet size limits.
Secondly:
What is the average delay on DNS resolution?
Another salient fact glossed over is that IPoAC completely depends on DNS caches as name lookups are expensive. As well as how long does it take to train new carriers til they are able to follow the new routes?
These and other questions lead me to believe that IPoAC is entirely VAPOR and has most likely not even been successfully implemented in the real world.
Does anyone have any real stats we can use to examine this? Or is IPoAC just going to be rammed down our throats by another mega-corporation with an agenda? It's time to really open the discussion on IPoAC.
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It's a shame there isn't a hydrogen electrolysis facility nearby to take the power when the normal users can't be reached.
The fundamental thing that is missing is the amount of power being generated.
You have to cool the steam down somehow, normally it looses energy by turning the generators but if that is not the case the energy needs to go somewhere.
The steam is normally re-condensed and then reused in a closed or semi closed loop depending on whether there are cooling towers. There is no way that the
cooling capacity would be able to dissipate the full load and hence the need to rapidly shut-down. This is the same for coal and gas plants as well.
The Xenon is what prevents you from starting the reactor once the grid problem has been fixed. Thus while the reactors had nothing to do with the cause of the shutdown, they can't simply be restarted the moment the problem is gone, you have to wait for several hours or even a day. The time period depends a bit on the precise reactor type, and some can be safely restarted without waiting for Xenon to decay. I don't know about the specific reactors in question, so I can't tell if this was an issue or not.
This is the same for coal and gas plants as well.
This is the key point that the idiot with the +5 mods above is missing.
This shutdown has nothing to do with neutron poisoning, and everything to do with load loss, the same as any conventional power plant. Negative reactivity from 135Xe typically doesn't prevent restart for an hour or so, and as the news is reporting the reactors are running again they must have had then back on line fairly quickly.
And yes, I am a nuclear physicist, and my undergraduate education as an engineer included reactor design.
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First off, There are not 5 nuclear reactors at turkey point. there are 5 units. units 1 and 2 are oil and natural gas(fossil) units 3 and 4 are nuclear and unit 5 is a gas turbine unit. The shutdown of the reactors DID NOT cause the blackout contrary to what the slashdot summary says. A failed switch and fire at an electrical substation outside Miami(read: not at the power plant) caused the grid to go into an imbalanced state at which time the plant experianced a loop(loss of offsite power) and did what they are supposed to do. There was no place for the power to go, so they shutdown to stop making it. All the power plants did what they were supposed to do. The fossils were presumably shut down. I'll find out more when I get to work. great, now i'm gonna be late.
Oh Crap, I'm an optimist.....
The AC had his facts in order. Even your quote backs him up. "The initiating event was a malfunctioning disconnect switch." The reactor shutdown was an (expected) response to the initiating event.
Fission products in the fuel have everything to do with why the plant was shut down. Operating nuclear plants run at a significant percentage of their capacity for reasons of economy. A sudden loss of load (as in the disconnect opening) results in the rapid rise in primary coolant temperature due to noplace for the energy to be dissipated. This will result in a reactor shutdown shortly after the load is lost (either by overtemperature or by turbine overspeed trip).
Heck, a sudden loss of turbine load can cause the turbine to overspeed, causing a turbine trip which in turn causes an automatic scram. Since every good discussion needs a car analogy, imagine driving up a steep hill and then knocking the transmission into neutral while keeping the accelerator mashed. RPM goes up, eh?
Even inserting control rods doesn't drop power fast enough to prevent heating up. After shutdown the fission products in the core continue to decay, releasing significant amounts of heat which must be dissipated.
That's what I love about slashdot... folks argue with experts without having a background to do so.
I'm an individual! Just like everyone else!
The solution is to have the power plant measure the phase of the lines they're on, and generate with a matching phase.
ROLFLAMO Power into and out of the electrical grid is not by the phase of the generator. Power into and out of the grid is by the prime mover, eg throttle and nothing else. Once a plant is online, the throttle doesn't change the phase, just the power. (infinate grid calcultions) Matching phase while connected is not monitored as the electrical locks it to the grid. Power factor is controlled by the voltage regulator. Over voltage produces a leading power factor and under excited generators produce a lagging power pactor. Excitation is used for correcting power factor with some voltage regulation/correction.
Matching phase is only something you do just before closing the breaker and it is almost always closed slightly out of phase by about 5-10 degrees leading while advancing (running slightly fast) so it can connect with little bounce. After that, it's in phase, even if the prime mover is shut down. (reverse power protection should relay it out at this point to allow it to stop rotating)
Disclaimer, I am not a powerhouse operator, but I am the son of a retired one.
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Yes, and still they fail. We had a somwhat interesting event at one of our sites in Sweden, Forsmark: When a fault in the outbound net triggered a shutdown in a similiar way, a power spike at the internal system forced all of the backup generators down, stopping power to the pumps. Fortunately, they were able to be restarted manually.
There is some debate about whether we had a risk of meltdown (our reactors *do* have some shielding if that would happend), but still the lack of safety culture was heavily critizised, and the event was classed as INES-2, and is regarded the most serious in Sweden.
The Forsmark plant was seen as a "flagship" plant for modernity and safety; hosting many demonstration tours and such. Stil there seem to be some "Oops" event beacuse of complexity ...
If they were going c through aluminum transmission wires, they damn sure had better be pulled over. Violating the laws of physics is no laughing matter, son.
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