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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.
Airplane Photos, Airline News, Planespotting Guides
It seems all slashdotters come from Florida!
:)
Yeah, I have a backup system
Quo usque tandem abutere, Nimbus, patientia nostra?
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.
512 MB RAM, 20 GB disk, 200 GB transfer, five datacenters. $19.95/month.
Last I checked, said 'nutcases' approved somewhat of nuclear power as being cleaner than coal?
I'm kinda curious as to why they shut down five reactors, though.
In Xanadu did Kubla Khan
A stately pleasure dome decree
Oh, wait. This is Florida. Things already look like a Mad Max movie, minus Tina Turner and with a lot more cubans.
www.voiceofthehive.com - Beekeeping and Honeybees for those who don't.
I'm glad I don't live in Florida :D
Oday ouyay antway otay ayplay away amegay?
Yeah we never had power outages before.
Idiot. No, not strong enough. Epic thinking fail.
Done with slashdot, done with nerds, getting a life.
your ideas are intriguing and i would like to subscribe to your newsletter.
---
Is this the MPAA? Is this the RIAA? Is this the DMCA? I thought it was the USA!
Move along. Before we call in the assistance of our Blackwater contractors to ensure that you do.
I wonder what Dave Barry will write about this one?
"Flyin' in just a sweet place,
Never been known to fail..."
Maybe someone from the future needed to rebuild their Dilithium Crystals.
Tin Whiskers
PDF http://nepp.nasa.gov/WHISKER/reference/tech_papers/2006-Leidecker-Tin-Whisker-Failures.pdf
Now we're going to have yet another round of computer scientists and other pseudo-engineers telling us how they would have done it better.
Uh.. Turkey Point has *2* reactors and 3 major fossil fuel generators (As well as several generators under 5 MWs).
has always been a turkey
it was bound to come to this point
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
The cause of the recent power failure in Florida is a result of a bad batch of E-meters ordered by the Church of Scientology. David McCabbage was unavailable for comment.
"All I wanted to do was get rid of these surplus theatans" sad a member of the "Church" went the city went black.
This report would continue, but it's gotten silly, silly silly silly.
Next Bruce Wills will show up and start saving everyone....
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*
Aw...crap!
If "disco" means "I learn" in Latin, does "discothèque" mean "I learn technology"?
So Obi-wan, do you support massive coal and old fired power stations that belch obnoxious substances into the atmosphere? I don't know about you, but I have kids, and I don't want to have to leave it to them, or my grandchildren to clean up our mess.
wait what? so what you're pretty much implying is that the global warming "nut cases" as you call them advocate for alternative energy sources like nuclear power and it's all their fault this happened? wow...
Sigs are too short to say anything truly profound so read the above post instead.
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.
Comcast is taking packet shaping to a whole new level.
just what technical problems could shut down five reactors?
If the article submitter had actually read the article, he might have noted the nuclear plants shut down because of an under voltage in the rest of the system (caused by a breakdown elsewhere). My guess is this is some kind of safety measure, otherwise why would you have the system shut down?
AccountKiller
Haha!
:p
Time for this Asia (China) resident to get his own back by tagging this story as 'andnothingofvaluewaslost'.
For those of you who don't know, a lot of the stories about Asian countries losing connectivity to large parts of the rest of the world were tagged as 'andnothingofvaluewas lost'. Of course, it could be argued that it is the countries that lost the connectivity that didn't lose anything of value, but hey.
I wonder why it is often stated that such places have lost their 'connection to the internet' when at least some of them probably don't much notice (China wouldn't notice much more than MSN not working, for example) - do people think that 'the internet' lives in the USA or something?
Max.
This is kind of a blow to the pro-nuclear power constituency, but outages are always a possibility. Safety nets and first response triggers are essential and this problem was corrected rather quickly so I still have confidence in the system.
On a side note:
I really hate how every problem requires a clarification that it wasn't Terrorists.
We live in a state of fear, and not a state of freedom. Are there people that really freak out and cry "Terrorists!" when something goes wrong these days. I'm not complacent just aware that the probability and capabilities of terrorist groups and there infrastructure aren't as ominous as the media and government perpetuate these days.
In fact, I don't believe any US nuclear power plant has more than three reactors on one site.
Ok, I'm slightly worried now. I have to read Slashdot to know about local events? Living in RPB, I had just retreated to my lair for an afternoon nap when the electricity flickered briefly, didnt think much about it since I have battery back-ups for all my goodies. House was warmer when I woke 2 hours later, I guess they don't make back-ups for A/C's? (Air Conditioners, not Anonymous Cowards) One a side note, why does every tiny little event require a 'terrorists didn't do it' disclaimer? Is this really the first thing that folks think when there is a minor inconvenience? Geeze, if you are that skeered better build a bunker.
Power tends to corrupt, and absolute power corrupts absolutely.
You're right, we should keep using oil instead. That way we don't have to shut down any nuclear reactors until we run out of oil. Of course, we'll be screwed when we *do* run out of oil, but we'll not have power outages until then. Oh wait, we will. Turns out nuclear power uptime is the same or better then coal or whatever other smoke bleaching power plant you want.
But feel free to continue with the pointless fear mongering over non-existent terrors. Florida is the one that's going to be under water anyway.
FPL just wanted to make sure everyone tested their backup generators prior to hurricane season.
DMCA - Chilling free speech since 1998.
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
(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!
It's sad, but thanks to FPL and our largely-complicit state legislature, Florida has the power grid of a minor rural village in a POOR third-world country. Name ANY other place in the developed world with the size, population, and average wealth of Florida where it would EVER be considered acceptable to have more than a hundred thousand customers without power for more than TWO WEEKS after a hurricane that barely left a dent in anything besides the power grid itself (Hurricane Wilma... 15 days, 17 hours without power... in Coral f***ing Gables, 2 miles directly south of MIA, right smack in the middle of urban Dade County, lest anyone think I'm talking about some distant exurb out in the 'glades...)
Compounding the problem is FPL's refusal to bury lines unless the host municipality provides them with a brand new 20 foot wide easement dedicated ENTIRELY to FPL. Remember the outrageous $100+ billion estimates FPL gave in post-Wilma press conferences when asked about the cost of burying power lines statewide? Most of the estimate was for easement acquisition via eminent domain. Why is it that power companies in Europe can dig microtunnels for power lines a few feet below the streets in ancient city centers without disturbing a single cobblestone, but it's somehow impossible for FPL to bury power lines below a 10 foot wide pre-existing grassy easement running through people's back yards?
FPL is the worst excuse for a power company in America.
It comes with a free Ron Paul and Ralph Nader subscription, both voted The Only Man Who Can Save America!
Never answer an anonymous letter. - Yogi Berra
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
The account I read stressed that two nuclear reactors had shut down in a way that implied they were the cause. They interviewed a plant supervisor who said things had shut down as they were supposed to and everything was OK, as they are supposed to say.
Right at the end the article also mentions that two coal-burning plants shut down as well.
Same thing, so why the emphasis on the nuclear plants?
If you don't want to repeat the past, stop living in it.
My company is moving operations into Florida this year, with this and the hurricanes we might want to order larger capacity UPS units for our MDFs and IDFs.
I smell something fivey .... the Pentagon!
Infuriate left and 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.
E pluribus unum
that THIS is exactly how we will end up if we allow it to happen.
And THIS is exactly how we will end up if we don't. Newsflash, buddy, but the nuclear plant had nothing to do with it other than "being there", the problem was in a distribution switch that failed. These failures will happen no matter how many tree hugging hippies there are or are not, but I'm sure you won't let that stop you.
Mod parent up for obvious reasons.
Remember folks, slashdot doesn't have a -1 "disagree" moderation!
Happens all the time....
There is a fleet of ships...ah.. trucks repairing these things round the clock.
More information Here (pg 34) and here
I Love It!
"Flyin' in just a sweet place,
Never been known to fail..."
I would want to know more about the maintenance on those switches, their rated capacity, and why enough could fail at the same time to reduce transportable capacity. Even with infinite switches, there'd be a non-zero probability of a complete across-the-board failure, but provided everything is well-maintained, you only need to guarantee that at any given point in the system, what you have spare exceeds what is likely to simultaneously fail, for an acceptable level of "likely".
Were there unnecessary single points of failure or inadequate backup mechanisms? Did so many switches fail at the same time because they were rated far too low for current usage or because poor maintenance degraded them below the ability to handle current usage? Nuclear reactors are extremely bad at handling dynamic loads, so what is going into developing mechanisms for soaking up (or burning up) power when grids do go offline? (Reactors aren't trivial things to restart.)
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)
...the operation of such a technology that requires to-the-letter operation and maintenance. Admittedly I haven't given this opinion hours of scrutiny, so it may be a little naive, but wadya think?
Here's a blog on the nuclear industry that I consider to be largely spin-free
So, can I assume Fox News is reporting this is the result of a terrorist attack?
"Heyyyyy youuuuu guyyyyyyys!"
The electrical grid is a really tricky system. You've got generators putting in energy at a bunch of points. And the whole thing is AC, which means that, if you look at any particular point, you see the voltage (and current) going in a sine wave. If you drive the system at the correct phase, you're supplying power; if you're slow by 1/120 second, you're turning twice your capacity into waste heat, and you start blowing up substations. Furthermore, since electricity moves at a finite speed along the wires, you can't just have a really good clock and have everybody agree; the difference in phase you need depends on the distance between the power plants along the wires. The solution is to have the power plant measure the phase of the lines they're on, and generate with a matching phase.
Now, if something goes wrong somewhere down the lines, the power plant may not be able to get a good read of the phase. At that point, you just shut down the power plant, shut down the substations (so there isn't customer load on the lines), get the switching stations fixed, start the power plant up again in phase, and reconnect the customers. It's only if the switching stations are really destroyed that they'd actually run a power plant for local customers disconnected from the national grid, and they'd have to shut it down again in order to rejoin the grid.
What happened today is actually how it's supposed to work in case of an equipment failure: a regional blackout, some time to repair the malfunctioning equipment or swap in replacements, and then restoring power. When the grid doesn't handle the failure correctly, power lines melt down and power company manholes and buildings blow up and service isn't restored for days to some customers.
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 . . .
Cue Horatio Caine.. 'Looks like someone's been left in the dark.. '
*removes sunglasses*
'permanently.'
There, fixed that for ya.
du duuh du duuh
whooo are you? who who who who
ireallywannaknow
whooo are you? who who who who
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
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.
This is somewhat a misleading title.
There was a problem with a substation that caused the Turkey Point reactors and other generating station to shutdown. This is a normal protective measure for all generating stations, nuclear or not. What caused the substation problem is the real issue here and what possible isolation methods can be used to prevent such a wide spread outage.
I used to be an substation engineer so it must have something really bad that cause a substation to trip generating stations that far up the line. Leaving the work safety grounds straps in substation and then re-energizing the substation can cause such a nasty drop in power in such a wide area and that would be one big ka-boom at the substation. In the San Francisco Bay Area we had that happen in the several years back and knocked some generating stations offline also.
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.
All they had to do was shut down the safety systems and manually reinsert the control rods.
Amateurs.
or else!
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.
1. Control rods are only made of graphite in fast reactors (the dangerous Russian ones). 2. Control rods are only fed from the top down in pressurized water reactors. 3. If you put too much cold water in a light water, thermal reactor (a reactor where fission is driven by low energy neutrons), then that reactor will go super prompt critical and explode. 4. I think after the early nuclear reactor designers, who probably knew the early bomb designers, saw what an atomic bomb could do, they decided it needed to be able to shut down quickly. After all, isn't it a popular rumor that Fermi coined the term "SCRAM", which stood for something control rod axe man, because there was a guy sitting on top of the pile with an axe so he could cut a rope holding a control rod above the core?
Neutron-absorbers have something to do with minimum down times for nuke plants.
I'd have to guess the reactors generators were over-voltage due to lack of load and that triggered the shutdown. I can't imagine they ran the reactors control systems off the Miami substation.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
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.
Long before then we will run out of money to pay to OPEC and China.
I prefer the "u" in honour as it seems to be missing these days.
Mod parent down.
Saying that "Nowadays one tries to break power generation up into much smaller parts" is a flat-out lie. Plants are as big as ever, and the majority of the baseline generating capacity being built today is many hundreds of megawatts for coal, and over a gigawatt per reactor for nuclear.
...this time it got me out of my Boundary Value Problems class.
I said "one tries" not "one does" or "you do".
Those pesky pirates can't plunder the booty without power, now can they?
Legalize it.
Speaking for myself, I am all for alternative energy sources. I'm just not so dumb to think that we can't operate safe, efficient, and productive nuclear facilities if we get our heads out of our collective asses. They provide far more power per sqft than anything else we have. They're SAFE and if you repeal retarded knee-jerk laws that ban fuel reprocessing they produce very little waste.
Nuclear is the future, like it or not, and we're falling behind, both in our power requirements and in technology advancements.
We (the USA) barely burns any oil for power. Exceptions are in Hawaii and southern Florida when they get their gas burn forecasts wrong. They (S.Florida) are a weeks flow down a constrained gas pipeline system.
The parent is misinformed and about as insightful as an average AC.
The GP is correct to a point. The hard greens want power to be as expensive as possible. They oppose any power generation technology that makes power cheep because of all the fun things we do with power. (Gonna be good mud in the Sierra Nevada this weekend.)
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
over its lifespan there are very very few plants that aren't profitable at any scale and many much more profitable than originally thought, look at entrgy and exelon profits in the last few quarters.
Nuclear power only makes money because of subsidies but then again almost all if not every power plant gets subsidies. Nuclear power plants wouldn't be built if they had to rely on Wall Street and commercial banks to pay for their construction.
FalconShould there be a Law?
A "reactor shutdown" DID NOT "darken South Florida". A total of eight power generators across the state (only two of which are nuclear) shutdown due to a sub-station fire South of Miami, and the failure of a redundant switch.
Power is now fully restored, WITHOUT the two nuclear units in operation (they take 12-24 hours to bring back up).
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.
No, I wouldn't have killed him. I would have killed the nearest person that doesn't know that would of != would've.
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.
"This message was sent from an Apple
Any missing rods?
Onda Technology Institute
I live in Palm Beach County, just north of West Palm, and didn't see a lick of this. Weird how patchy the outages are!
Kwisatz Haderach
Sell the spice to CHOAM
This Mahdi took Shaddam's Throne
Before I answer every reply I'll just reply to myself:
Perhaps I should have made myself clearer: I am not for cellar nuclear power generation. I know that nuclear reactors have to be large to be efficient. That's just the point, that makes them less useful.
The reactor automatically shuts down when the voltage drops, the diesels can keep it going but when a whole grid drops out what's the point? Let them get the grid back up along with numerous surges and sags in the process; when things are stable again bring the reactors on line.
Apocalypse Cancelled, Sorry, No Ticket Refunds
If you are not familiar with this then you should read the reactor fundamentals handbook link above. This isn't rocket science.
At least not at your security clearance.
"nuclear power plant operation isn't rocket science"
- and that's why we don't have regular interplanetary space flight
I am not a nuclear engineer, so maybe I'm missing something obvious. That said, I don't understand why the system would automatically shut down due to a no load condition.
I understand why a backup generator for a house does this. It's to prevent linemen from getting killed touching lines that they assume are not hot while repairing a downed power line. One would not expect a lineman to assume a nuclear plant's output lines are not hot, however, so that reasoning doesn't apply.
I might be able to understand them shutting down the power output, if only to avoid problems when they have to resynchronize the phase of the power when the lines go hot again, but I don't see any reason that should necessarily be linked to the operation of the nuclear pile. The nuclear pile is just moving a bunch of steam around. It can do the same thing whether the turbines are under an output load or not.
At worst, I'd expect the water to move faster through the turbines because there wouldn't be as much resistance to spinning them, and maybe not even that, assuming there are governors on the turbines... unless, of course, the governors are simply insufficient to handle that situation, in which case that screams "design problem" to me.
I assume that the multi-day outage could have been avoided if the reactor were brought down slowly instead of being scrammed. If so, one would expect that a human being should be required to push the button to shut down a reactor for lack of load reasons, particularly when shutting it down completely requires a multi-day rest period for reaction byproducts to degrade. I would expect that the only time a reactor would be scrammed automatically is when there's a safety risk to its continued operation, and I don't see why a decreased load would qualify as a safety concern.
Am I missing something fundamental here?
Check out my sci-fi/humor trilogy at PatriotsBooks.
...shut them all down!
Oh no, R2, they're dieing....
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
What the hell are you on about? Load rejection or loss and a sudden shutdown without a nearly immediate restart can certainly result in Xe buildup requiring a delayed restart. Doesn't matter what caused it. I think the OP was just making the observation that the restart will take time, and will likely cost the utility $$$'s (esp. if they have to import power to meet baseload temporarily or fire up expensive peak assets).
for example -
http://mailman.mcmaster.ca/mailman/private/cdn-nucl-l/0309.gz/msg00002.html
"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
gadgetophile.com
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.
Cwm, fjord-bank glyphs vext quiz
awe... I killed the person next to me just as I started reading your post, why did you save that part for last?
my UID occurs in pi starting at the 384,199 digit after the decimal point.
"and forcing some shops to close before power was restored to most customers by Friday evening."
editors'r'us
As my evil minions say, "Hail Eris."
-- Nate
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.
"It's a terrorist attack!" ..rather than the more-mundane, Occam-compatible, reasonable, probable conclusion that power plants had shut down for less-than-terroristic reasons?
Is Capitalism Good for the Poor?
great point, but you cant exactly turn a reactor on whenever you please. If it was scrammed from high power, it could take around 10 hours to start the reactor back up. This occurs because Xenon builds up in the core, absorbing neutrons like mad. YOu have to wait until it decays away until you can start up again.
because next week is Daytona Bike Week and a few more hundred thousand people would have been visiting the city at that point. Depending on whether the entire city was affected it wouldn't have been good for a city with that many *extra* people to lose power.
this nation, under God, shall have a new birth of freedom. -- Lincoln, Gettysburg Address
It's pronounced NEWK-yoo-lurr honey, NEWK-yoo-lurr.
-Arthur
Cave ne ante ullas catapultas ambules
and he told me that a massive transmission cable went down by aligator alley
The real story is that a bunch of electrons were pulled-over by a cop in Waldo for going c in a 25mph zone.
http://www.city-data.com/forum/florida/5365-moved-waldo-florida-speed-trap.html
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.
Blasphemy is a human right. Blasphemophobia kills.
I believe the GP was discussing what happens when the reactor is running and is forced to shut down. It is an explanation for why the reactor would take time to start up, not for the reason why it was shut down in the first place.
From what I gather, the chain of events goes something like this:
1)Reactor operating
2)Loss of outside power requires an emergency shutdown of the reactor(s)
3)The reactor has X amount of neutron poison (Xe-135), where the concentration of X is related to the power level of the reactor before shutdown
4)The concentration of neutron poison does not immediately lower, and the reactor cannot start with high concentrations
5)A wait is required while the concentration of Xe-135 drops to a level that allows the reactor to be restarted. This wait can take quite a bit of time, as the Xe-135 is mostly being produced from the decay of I-135, which has a half life of ~6.7 hours and the Xe-135 has a half life of 9.2 hours.
LOL
Nothing to see here; Move along.
Actually, if it's anything like where I work, roughly half are powered from the main generator via a transformer and the other half from the grid [via a separate transformer located within a different segment of the local distribution grid]. The electrical loads can be shifted entirely to one source upon a fault.
The plant couldn't remain in this condition indefinitely, however. Requirements called "Tech Specs" (Technical Specifications) require this redundancy and require [under force of law] the reactor shutdown following a set amount of time.
Those backup generators you mention are not intended for overall plant operation. They are intended to provide local power in the case of a reactor accident with offsite power unavailable and/or to cool down the reactor to a unpressurized state.
One of our reactors also has a "stability trip" where it is automatically shut following a loss of a certain portion of the grid. This is intended to ensure adequate load remains on the grid for the power being generated. Sounds like this same idea happened at Turkey Point.
Don't have a clue in the world how this stuff works. Got it.
See, like this jar here containing a rod of... uhhh.... ah...
looks like latex actually.
Surrounded by a solution of...
ummmmm.....
uhhhh....
Hmph. Never mind.
Seemed pretty radioactive at the time.
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.
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
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!
Windows NRX (Nuclear Reactor Experience)
(Sadly, I actually think this is likely part of the problem)
I live in West Miami. I should have been affected by the outage, but I believe I get my power from the west coast. My power flickered off for a second. Here's the really interesting part. I'm a comcast customer. While the whole of south FL was offline, here's what I was getting on speedtest.net Speedtest Results 101Mbits!!! A 6Mbit cable line was getting 100Mbits while everyone else was offline. What gives? Why all the blocking? Why all the hating, comcast?
They're using their grammar skills there.
You are correct. There was a switch failure that caused the precautionary shutdown of the reactors. It's always a good idea to err on the side of safety when dealing with nuclear reactors. 4 million angry people is still better than 10 million glow in the dark corpses.
I still say it was someone stealing copper. I imagined it was a guy named Chad and he was found still hanging from the power line.
The Liberal-controlled press invented this story, even dragging out stock photos, to try to convince voters that Nuclear Power is not reliable.
Surely, we at Slashdot know beyond all doubt that Nuclear Power is reliable, fundamentally reliable, and reliable above all other forms of energy. Moreover, it is "Safe and Clean" so if you see any more stories about radiation leaks, and plutonium being flown over the US in an unsecured airplane, don't fall for it. The Left is just making up lies to discredit the one socialist program we Republican love best - single-payer-nuclear-insurance_&_ subsidy_program. Government does energy best, so anytime the government decides winners, the best technology wins out. Worked for Corn and Stalin, works for nuclear power. No other form of privately-developed-power provides as much power as the government-funded nuclear industry - so nuclear is better, and more reliable damn it.
AIK
I should note that the ability to overcome the xenon transient is dependent on the geometry and neutron moderator configuration of the reactor. There probably are some reactors out there that would not be able to start up immediately. A link further down the page indicates that this is the case for heavy water-moderated CANDU reactors, which use natural unenriched uranium. The 20-hour startup I mentioned above occurred at a boiling water reactor.
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. Lucky Amerikanos, living everything in excess. And here we are in Pakistan, not knowing where to get power from.
Total power loss on the UK grid in 2005 was 1423 MW out of 63 total demand.
Hardly most of the power lost in transmission.
Sources - http://www.nationalgrid.com/uk/library/documents/sys05/default.asp?sNode=SYS&action=&Exp=Y
Trying to become famous by taking photos. Visit my homepage please.
Maybe you could figure out a way to harness the hot air coming out of your regions leaders? I'm sure you could drive a few turbines with that!
According to various reports, the outage began with equipment failure and the loss of a distribution substation. Unlike major transmission links, distribution substations feed local loads and are not a part of the transmission system critical to the movement of power between alternate sources. The loss of a distribution system results only in the loss of loads, not generating or transmission capacity.
Two things may have happened here. Neither bode well for the system's condition.
It is possible that, following a fault at the distribution substation, the primary protection relays failed to operate. There are (or should be) backup relays. But these typically take longer to operate and allow the fault transient to push the system into an unstable condition. This is bad design. System stability should be maintained even if one station's protection fails.
It is also possible that, in spite of the proper design of primary and backup protection, the regional grid is being run too to its stability limits. A fault condition properly considered in the system design which should not have caused stability problems did so because the system was being run beyond prescribed limits.
Both of these possibilities suggest that, in spite of the big midwest outage we had several years ago, lessons have not been learned.
Have gnu, will travel.
A great big resistor (could be just an arc) should do the job. You could store the heat by melting salt.
I watched nexus to terrorism and I thought it was a great movie; my girlfriend thought it was great too.
We saw the sequel, but it wasn't as good. I'm hoping to see "Nexus to Terrorism III" ASAP.
Need Mercedes parts ?
That still doesn't answer my question, though. Why stop turning the generators at all? Seems like you could either introduce a dummy load on the output or use a governor to limit the speed of the turbine shafts (adding drag) and get the same effect while allowing for a graceful shutdown.
Check out my sci-fi/humor trilogy at PatriotsBooks.
Because then you're producing megawatts of heat in your generating plant....not a good idea.
An Obamanation talking about "the enemy" forming Smug. Hah.
For context, click Parent.
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 ...
Dustin, who has featured on the Irish television show 'The Den' since 1990, will sing the song 'Irelande Douze Pointe' at the finals in May.
No, seriously. It's profits that causes these troubles.
When you're a corporation, your primary goal is profits. If something bad happens, that's ok as long as the cost of it happening is less than the cost of measures to avoid it. So you accept a certain number of faults and failures, namely that percentage that's too expensive to avoid.
When you're not a for-profit company, your focus can be different. For example, an energy company owned and operated by the state would have as its first priority to supply energy to the people and the industries of the state. It would invest in more measures to prevent failures, since avoiding blackouts would be a higher priority than profits.
I see this weekly with the german train company. It was made a private company 10 years ago, and ever since, service has gone down the drain while costs have risen. When it was run by the government, trains were on the minute and going every hour between major cities. Now that it's a private company, most trains are crowded, many are late, and lots of connections have been discontinued, but you get coffee brought to your seat if you travel first class. Well, that's nice, but I'd rather have my reliable, punctual train service with no crowding an plenty of connections back.
Assorted stuff I do sometimes: Lemuria.org
Something similar happens with coal or oil fired stations - the air intake fans use synchronous motors so their speed is directly linked to the grid frequency. If the load on the system increases without being matched by more generating capacity that frequency drops slowing the fans and reducing the intake air. With less air they can't burn as much fuel and hence produce less power making the problem worse. Below a certain frequency the system cannot recover and shuts down. Automated load shedding and similar is set to operate before this point - in the UK there is a total of 2.5GW that will be automatically shed if the frequency drops below 49.8 Hz (nominal frequency 50 Hz) This is from a peak demand of 60GW. See the wikipedia page for more details.
The Trustworthy Cyber Infrastructure for the Power Grid (TCIP) group at UI-Urbana-Champaign has some applets demonstrating how the Grid works. It seems to be impossible to distribute power from any source (hydro, wind, nuclear, coal...) to any load without a connection to the external grid.
If the internet were like the grid, you wouldn't be able to use your PC unless it were connected to the internet. I personally think the future grid will have a few of these large aging doorstops like the Turkey point reactors and the enormous new coal plants being constructed in SE Wisconsin and elsewhere. But many people will choose to have their own Solar shingles, MicroWind turbines or (more likely) Heat/Electric co-generation fuel cells in their basement. You probably won't see nuclear in the house for the next 100 years, but co-generation almost makes sense now, especially in cold climates where fuel cell waste heat can be used for hot water and home heat, moving efficiency well above 90%.
As is pointed out by this outage, big ugly centralized generation is profitable to the monopolists who control the generators, but not nearly as reliable as microgeneration could be. The massive ERGS coal plant being built in Oak Creek, WI will depend on the delivery of over 1000 rail cars of coal each day, which all comes via a single rail line. How much more likely is a failure of this (and 2400 Megawatts) than the simultaneous failure of hundreds fuel cell cogenerators on a day when there is also no sun and no wind?I haven't checked the price of 1000MW rated resistors lately, but I'm guessing its not cost effective [/sarcasm]. Seriously though, that's an absurd amount of power to try to drop resistively, and you have to not melt your power plant in the process. And "governors"? Governors usually work by limiting the fuel input to a motor. In this case we'd be talking about closing the steam valves and pushing less steam into the turbine, which is the opposite of what we want. I guess you could put some kind of brake on the turbine shaft to add drag, but again, a brake that can dissipate 100s of megawatts of energy? Without melting itself, the turbine, and the whole rest of your plant?
1GW is huge amount of power, to give people some idea, very few houses have an average load of more that about 0.5 a kW ( .5kw * 24hours * 90days * 10pence = £108 per quarter bill) most are way below that. So you are talking about the equivalent of about 2 million house supplies! Or say 1million electric bar heaters, which if you laid them out each within a square 0.5m * 0.5m you would need a field with 500m sides and it would be seriously warm!
> So how fragile is the electrical grid
.US, but in .EU most countries have import/export agreements with their neighour counterparts, so that even if several plants were to fail, a minimum service would still be available if not instantly, then at least within a short time. Since the .EU power landscape is divided into the various national companies, it is unlikely that a specific vulnerability / maintenance oversight / whatever happens in multiple countries simultaneously.
:-)
Well, that depends on what kind of failure you're looking at.
If you're talking multiple power plant failure, well... I'm not sure how the situation is in
Physical infrastructure-wise, I think the routing on the high-tension net is sufficiently resilient, but the local distribution cabins, and possibly up to some high-to-low transformation stations are probably weak spots.
Electrickery-wise, you'll find that the entire net actually acts like a capacitor. If you could shutdown each and every producing element on the entire grid simultaneously, you wouldn't actually notice until moments later. I haven't got hard time values, but I'd guess we're talking minutes. Thus, momentary interruptions are not a worry. I remember stories about electrical technicians being used for IT infrastructure maintenance, and shutting down or patching equipment without notice because they were used to being able to do that on the electrical grid
What a depressingly stupid machine.
Whoops, I forgot to review my draft before submission, sorry Mr. / Ms. Grammar Nazi! I so beg your forgiveness, shall I bend over for you so you can administer punishment?
>>All critical systems have at least double redundancy, that's why nuke plants are so darn expensive to build.
Nuclear plants were especially expensive in the early days, before they decided that they didn't need to design 3X the breakrooms, stairwells, vending machines, and windows. Female employees were pleased by the plentiful bathrooms, while male employees were pleased that every computer came with three kinds of solitaire.
Of course, the sidewalks are still a mess, as any nuclear engineer can attest.
-b
No offense, but I've stopped responding to AC's.
(Trust me, I hate how unverifiable this sounds) One of my friend's father is connected with the government. I was told that there was the order to shutdown the power plants was actually given by homeland security due to a terrorist threat.
We had something similar happen in 2002 here in Jacksonville, Florida (Duval County). Our power company is Jacksonville Electrical Authority.
One bright spring day around 3:00PM there was a fire at a sub-station that caused a chain-reaction shutdown of all the power stations in the county. We had hot dogs over a Coleman stove that night. Power was restored at around 11:30PM.
In a nutshell, it seems that what happened this time was the same thing, but on a grander scale.
The funny part for me was that at the time (2002) I was working at a PC shop in a mall. I was working on a particularly old and recalcitrant workstation. I had lost all patience with the old crate. Just as I jabbed the power switch off the lights went out (in a room without windows). After fiddling with the circuit breaker box with no luck, I sat down in the front of the store where I could hear the mall's personnel saying not only was the power off in the mall, but the entire neighborhood was out!
I thought it was all my fault.
I was very relieved when I learned it was caused by something other than a flakey PC.
dagenhamdave
Much handwringing here from the nuclear fanboys about how people are "misreading" this story.
However, the fact remains that relying on nuclear or any large generating stations makes the grid less reliable. Period.
Reliability is one benefit (of many) of small and distributed generation.
And yeah, reliablity matters.
As for small nuclear, in the real world the new nukes that are being proposed in the US are all in the 1,300-1,600 MW range.
MOD PARENT DOWN(-1 Democrat lacky)
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I love that terrorism even had to be mentioned. "Sorry for the fairly minor inconvenience, folks, had to deal with a very mediocre terrorist." Idiots.
One significant terrorist attack in 20 years and everything now involves it. Those guys were good, they don't even have to do anything for another 20 years and we're still running around looking for terrorists.
...and bring the dinosaurs back. So you're saying they could solve our energy problems? Sweet.Actually, nuclear plants ARE dependant on grid power for operations. It may seem odd that a plant generating many megawatts to a gigawatt of power needs an external supply, but it's a matter of safety. Were the plant to run exclusively on it's own power, a single malfunction could leave it in a state where it has no power for coolant pumps yet the reactor is at full power. So, if grid power to the plant drops, the reactor shuts down immediatly as a precaution.
The Chernobyl plant was carrying out an experiment to see how well it could shut down using energy from the inertia of it's own steam turbines in the event of a secondary cooling failure with no grid power. That wasn't a direct cause of the disaster.
When an outdated, crumbling, power infrastructure is more likely to shut down the U.S.A.?
North America's power grids are seriously in need of fixing/upgrading. Single-layer redundancy isn't enough when a system is old enough to cause failures in two or more locations at the same time.
Put all that cash spent on the war for national infrastructure to strengthen where you stand, America, or else you might find yourself standing in quicksand!
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.
Coding with assembly is like playing with Legos. Coding an application in assembly is like building a car with Legos.
At the risk of beating this to death...:
Cue Horatio Caine.. *tilts head*
'Looks like someone's been left in the dark.. '
*removes sunglasses*
'permanently.'
False. Toshiba sells a unit that is 20x6 feet in area, and can generate 200 kW of power.
This is one of those posts I wish I could mod to +6 Insightful. A +6 would signify that the post is one for the ages, stands out among the best of the best, maybe there could be a feature on the site to pick out the +6 posts (yes I realize this would put the "best of slashdot" site(s) out of business). Maybe once a post reaches +5, another 5 or 10 mods-up could take it to a +6. I wish that were possible.
:(
That, and I also wish I had mod points right now
"When information is power, privacy is freedom" - Jah-Wren Ryel
Why not just pull up rods to maintain primary and secondary conturs with so little vapor turbine barely spins?
You are using English. Please learn the difference between loose and lose; they're, there, and their; your and you're.
I'll take one more swipe at it:
Cue Horatio Caine.. *tilts head*
'Looks like someone's been left in the dark.. '
*PUTS ON sunglasses*
*Looks off into the distance*
'permanently.'
Yes but:
Oh my god, there was an electrical fire in a substation and all of the safety protocols worked flawlessly, EVERYONE PANIC!!1!1ONE-ELEVENTY1!!
Doesn't make for a good headline. Now, throw Nukular in there somehow and we can whip up some real panic.
Necessity is the mother of invention.
Laziness is the father.
Nuclear is likely not the issue as much as steam turbines. Steam power is pretty interesting, but the design of modern efficient turbines require that they have long startup times. This is to eliminate problems of differential thermal expansion. If you start a turbine quickly, the inside heats up (and expands) faster than the outside, causing the inside (the rotating rotor+blades) to expand into the outside (the stationary case) with catastrophic results.
More efficiency requires closer tolerences, which means less fudging on thermal expansion rates. So, you are effectively trading away operational flexibilty (can't shutdown and startup on a whim) for more fuel economy. Not that steam has ever been capable of quick startup, it takes time to heat up all the water in the system.
My understanding is that a typical steam turbine will take 12+ hours to go from cold slow roll to full speed/full power. But, perhaps in this case FPL was able to keep the steam temperature up and the turbine hot until they could restore the load...
This isn't rocket science
Nothing so baffling. This is merely nuclear science.
Heisenberg might have been here.
Just in case the presidential vote isn't going the right way and Diebold can't stop it. They need a backup plan.
Have gnu, will travel.
Wrong regarding houses. There is a 200A 115V supply to this house. But the max peak power used is about 5kW for geo-thermal heat pump, another 60A for oven,hot water tank and clothes dryer (well, maybe 6kW peak from that). Aside from that, there can be 500W for other stuff.
Of course, this is not running 24/7 but peak peak is clearly above 10kW. Monthly power usage can be 2-3MWh or so (2-4kW load - 4-8x your guesstimate). At 5c per kWh, it is about $1000-$150/mo. Or maybe 50-75 pounds/mo. Now, this is purely electric (hydroelectic) supplied house and it is very energy efficient. No gas/oil here. Temperatures go down to -30C in winter.
Also, 1GW is not exceptionally large. I think the power conversion ratio from heat produced in thermal electric plants to electricity generated is something like 35%. This means 65% of the heat has to be dumped. So, to produce 1GW electrical power, you need 3GW thermal power. Now, the florida reactors (AFAIK) are on the coast. They can dump more heat into the ocean if there is a need. Shutdown is just more prudent as you don't know the cause of the low-load is.
Aside: Cooling towers don't work so well hence they are not used by any modern reactor.
That way, if the grid went down, there would be SOMEWHERE to dump the output of the alternator, at least until the plant can be shut down in a controlled manner.
Large backup generator installations have load banks installed so that the generator can be tested under load on a regular basis, without actually having to cut the facility power off of the grid.
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I completely agree with you, however my stats for houses in the UK are pretty accurate the average UK domestic electricity bill in 2006 was 95.75 GBP per quarter and average electricity price of about 9.9p/kWh this is mainly due to the fact that most houses are heated with gas or oil. Standard UK domestic supply available capacity is 100A at 240V.
I am interested to know why cooling towers are not used, I understand that when near the coast or large river it is far better just to dump the heat into water but when that is not available I believed they were the most efficient way to dump heat into the atmosphere, apart from the planning issues. I understand that a forced convection method would be more compact but it would consume quite a bit of power?
Actually both units are still shutdown in hot standby. They rods are in all the way and we are still at temperature and pressure. At least as of when I left at 8:30 this morning, but that's because of other reasons. We are using this unplanned shutdown to fix a couple things that can only be fixed when shutdown. As each day the reactor is shutdown costs about 1 million in fossil fuels to replace the energy produced; they don't shutdown until absolutely necessary. Unit 4 is about to go into an outage anyway, so there was some speculation as to whether we would have enough left to startup without worrying about poisons, but we already had a sno(short notice outage) so there's plenty of fuel left in the pot so to speak. As for the reactor being xenon poisoned just because it's lost load... I'm pretty sure he's full of shit. If there's no where for the power to go then you've got to shut down. If you didn't then yes the turbine would overspeed and wipe a bearing or fuck itself up. Just the overspeed condition would draw more power from the reactor and it would cause a rise in reactivity. Even though we lost power we still had battery backup banks and 4 emergency diesel generators that are up within 10 seconds. The Reactor Coolant pumps are weighted to make sure they have enough momentum if they lose power for a few seconds.
Oh Crap, I'm an optimist.....
The condensers which would be how you would get your heat into the ocean can only handle a 50% load reject, they're doing that right now and we're also using steam dump to atmosphere.
Oh Crap, I'm an optimist.....
I'd just like to point out that you two are talking about two different things. you are charged by the watt-hour whereas power plants measure in watts. one is over a unit of time, one is instantaneous. I use about a megawatt-hour per month. Turkey point unit 4 produces 735 megawatts every instant. The heat output is three times that. Producing energy will be very inefficient until we figure out how to pump steam.
Oh Crap, I'm an optimist.....
While you might lose some efficiency, there's an argument that if you can build your reactors on a production line, take them to the location required in only a few pieces rather than thousands, and screw them together in a few months rather than years, the overall economics might improve.
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
That's not the case for all nuclear plants. Years ago, I toured a plant and they had 2 locomotive engines to act as a back up power source (they were cemented in place, they won't going anywhere). I suspect that shutting down the reactor is costly and a big hassle to get running again, so I would expect that many plants would have a similar set up so they could keep running in case they lose power from the grid.
The duration of a xenon precluded core depends on a lot of factors, two of which are core age and operating power level. Some reactors don't suffer from xenon preclusion until the core has been in operation for awhile. The duration of the shutdown due to xenon has to do with the ability of the reactor/operators to overcome the huge poisoning affect of the xenon that has built up in the core during operation. If the core is operating at a high power for an extended time, xenon will be at a much higher level than if the reactor was operating at a low level for the same time. The result is a much shorter shutdown time at lower operating power.
The Turkey point reactors were back up in a matter of hours which leads me to believe that they were either: a) operating at low power before the shutdown, or b) the core is young enough not to suffer from xenon preclusion.
They pulled themselves over after seeing their own Cerenkov radiation and thinking it was the cops.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Coal gets more subsidies than we of nuclear power do, not to mention "clean energy" initiatives.
According to TFA in Bush's energy proposal coal gets 21%n increase in federal funding and nuclear energy research gets a 40% increase, alternative and renewable resources on the other hand don't get as much. Wind for instance get 6%, a $3,000,000 increase. And "solar energy would decrease by $12 million, a 7 percent reduction from this year." Together for solar and wind that's $15 million yet the total proposal for climate change programs is $8.6 billion, so even if other alternative sources get another $70 million that's still only 1% of the total. Where's the other 99% going? I doubt coal and nuclear don't get more that 75% of the total. As compared to solar, wind, and others that sounds massive to me.
I'll note this new solar CSP plant they want to build in Arizona. It's noted here that this will cost somewhere in the 4 billion range and generate 280 megawatts, with a ground footprint of 1900 acres. Compare this to my plants, which generates nearly 2,000 megawatts with a ground footprint of maybe 20 acres.
You left a large use of land for nuclear, the mining. Then you have land needed for long term storage of the waste. As uranium mining is volume intensive, the concentration of uranium in the ore is so low, so it requires a lot of land. And it's environmentally destructive. The Navajo have basically been dumped on, uranium mining threatens their source of water, the aquifers under the land.
Call me prejudiced, but I'll stick to nuclear thanks.
Go ahead, and store it in your back yard too. You can also mine uranium from your back yard.
FalconShould there be a Law?
Well said
Coal!=Oil
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'