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NRC Engineers Urge Shutdown of Nuclear Plants If Design Flaw Not Fixed (utilitydive.com)
mdsolar writes: A group of engineers in the U.S. Nuclear Regulatory Commission say they have identified a design flaw in nearly all nuclear reactors in the country that should result in their mandatory shutdown unless operators fix the problem, Reuters reports. In late February, the engineers petitioned the NRC to order immediate enforcement actions to correct the design flaw, which they say could result in damage to cooling systems and ultimately lead to an emergency situation. The filing asks the agency to respond by March 21 and is a part of a standard NRC process, according to the news outlet. The filing stems from an incident in January 2012, when Exelon's Byron 2 unit in Illinois experienced an automatic reactor trip from full power after an undervoltage condition was detected. The unit was shut down for a week, in what is known as an open phase condition created by an unbalanced voltage. The NRC engineers say such an event could cause an electrical short, reducing the abilituy of cooling systems to operate.
Why are all these non-stories submitted by mdsolar being approved? They identified a possible flaw and recommended a fix. Nothing to see here, move on.
In short, the catastrophic problems at both Chernobyl and at Fukushima Daiichi, despite different reactor designs, were coolant/steam problems. In Chernobyl's case steam voids within the graphite-moderated core caused the pressure to grow to the point it blew-off the upper biological shield, exposing the reactor core and blowing chunks of it out into the environment. In Fukishima Daiichi's case, as temperatures grew steam formed and also hydrogen and oxygen were separated-out from water, so steam and hydrogen explosions resulted.
Keeping that reactor cooled and preventing the buildup of steam inside of the system should be top priority.
Do not look into laser with remaining eye.
Gee, it's mdsolar and his anti-nuclear rants again.
I'm shocked, shocked to find that gambling is going on in here!
It's not like the country needs power or anything...
The country doesn't needs nuclear meltdowns; neither does its power grid. If you shut down power plants, power gets more expensive and other power plants open. If a reactor melts down, not only is the land around it unusable for a while but the irrational public says, "ZOMG! Nuclear!" and you can't open a new nuclear plant for forty years.
If there is a problem, and there's no reason to believe there isn't, it should be fixed now before the height of summer A/C demand. Cooling is an incredible draw on our power supplies and the world is just getting hotter.
Unsurprisingly, mdsolar is posting this as soon as possible, because he has a hard on for hating on solar power. They've had a whole 96 hours to think about this. The world is going to end! OMG! They're not doing anything.
I'll just ignore this for a while because, frankly, this is way too early to give a crap.
FWIW, the 2012 incident didn't do anything anyone but a solar panel hugging, nuke hating asshole would care about, either. It will be corrected, but as far as emergencies go, this one isn't one because it has happened 13 times in the past 14 years and... nothing of consequence happened. It will happen one more time before it's fixed and... nothing of consequence will happen. It went unnoticed for several weeks and... nothing of consequence happened.
But, because nuclear safety is taken seriously (unlike employee safety when installing solar panels) this will be corrected quickly and without incident.
This is actually a pretty standard procedure when any flaw is found. Since the NRC doesn't operate or own the plants, they can only request that a problem or flaw be fixed and give the consequences of not fixing the flaw to the owner/operator of the plant (and in this case, the NRC engineers are recommending the shutdown of the plant if re-mediation is not made).
We were all warned a long time ago that MS products sucked, remember the Magic 8 Ball said, "Outlook not so good"
Doesn't sound like it's a major design flaw; they just have to detect an open phase condition more quickly, or provide an alternative power source to the emergency cooling pumps.
One of the few happy lessons from Fukushima is that defense-in-depth works -- at least to prevent mishaps from developing into the worst possible scenario. So we shouldn't be cavalier about the potential loss of one of our layers of protection.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
The risk isn't meltdown - it's emergency shutdown. Did you read TFS?
Actually, according to TFA, the risk is reduced ability of the emergency cooling systems to operate. This is basically what happened in Fukushima, and it led to something much worse than emergency shutdown.
Um, nothing happened to the cooling system in Fukushima, the backup generators and power feed lines were washed away, leaving no way at all to power the cooling systems. This is hardly the same thing.
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
So the bird poop don't get in...
I believe that there may be an issue that needs to be addressed. But the hyperbole? Nah. If this flaw has been around for all this time without being triggered, it's probably overkill to call for such an extreme response. How about maybe a "we need to fix this reasonably soon" reaction instead?
As soon as I saw the word "nuclear" in the subject, I knew who the submitter was.
For those new around here, mdsolar is Slashdot's long-time anti-unclear troll, so I'm posting this as a forewarning to you. His posting history shows he regularly contributes anti-nuclear articles, and when he gets told, he typically resorts to personal attacks on those he disagrees with. If you're not interested in going down this path, the best option is just to ignore him. As they say: don't feed the trolls. Now if we could only get the powers-that-be here to ignore his submissions...
"Politicians and diapers must be changed often, and for the same reason."
...the land around it is unusable for a while... LOL, I guess if you consider several generations 'a while'.
No. The risk is failure of the cooling systems.
An open phase fault means that one of the three power phases has lost voltage. This would not trip over current circuit breakers, and some equipment like motors for pumps and cooling systems may continue to operate, but their performance would be severely degraded, or if stopped may fail to start, even though they appear to have voltage. Under these degraded conditions, motors may be internally damaged by overheating.
Phase loss detection relays are fairly standard for sensitive equipment. In the event of a phase loss or phase with low voltage, all 3 phases are tripped, cutting all power. A backup power supply can then be selected.
...and it's apparently a standard in all of the nuclear reactors in the country, only one of which had one single event. Which didn't do any actual damage.
Yeah, I'm going to go with "this isn't that big of a problem in reality" for $1000, Alex.
The same blog notes a continuing problem with slack operations at the Springfield plant. Because of its hiring of two-dimensional yellow employees with diminished concern about safety and a poor diet, closure of the local Lard Lad franchise and alcoholism awareness training for all employees was recommended. Video of high-level waste being accidentally brought home in an employee's car and being tossed out onto a public street when discovered was submitted to the NRC in evidence.
MDSolar and his crowd are preparing lawsuits as we speak so 3 years from now he can cite the millions of dollars spent defending frivolous suits as why Nuclear is too expensive.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
Nuclear accounts for approximately 20% of the power generated in the US. How, pray tell, does the NRC plan to replace this generation capacity?
It will be cheaper to fix the flaw than to shut down and fixing is an option.
The emergency that this particular flaw leads to is a reactor shutdown, which is exactly what happened at Exelon's Byron 2 unit and (according to the linked article) it's happened 12 other times in the past 14 years. And what do you know? No meltdowns.
For this to become a meltdown, the reactors would have to have other far more serious flaws that prevent them from shutting down properly. That clearly isn't the case here.
They won't be replacing anything. These engineers petitioned the NRC all of 3 days ago. The NRC hasn't ruled on anything yet. And, should they put in some kind of regulation for this to be fixed (and they should), the operators will fix it the next time they are shut down for maintenance. And nothing of consequence will happen at all. The world keeps turning, and these reactors keep boiling water.
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
The incident happened in january 2012. They ought to have had enough time to think it through now...
Also, if you read the NRC request rationally, they are saying: fix this, if you don't fix this then you should shut down.
They are not saying "shut them all down, immediately."
Yeah, I mean, the reactors are water cooled, right? Seems like Fukushima had plenty of water ;-)
On that same line, the FIRST TIME it happened was in Jan 2012. All reactors combined went several thousand years of operating time without an incident occurring... Just to give you an idea of frequency of this type of event is.
We were all warned a long time ago that MS products sucked, remember the Magic 8 Ball said, "Outlook not so good"
Some risks aren't work taking. I'm not a nuclear engineer, and can't speak directly to the issue here. However, if a nuclear engineer intimate with the details speaks up in such a manner, and especially if a group of them do, you'd damn well better pay attention. Engineers don't use hyperbole. If they say this is a problem that merits shutting down reactors it does.
Two of my imaginary friends reproduced once
The world could use more nature parks.
"The problem wasn't the cooling system, it was the fact that the cooling system didn't work!"
You are welcome on my lawn.
Allowing idiots to marshal public sentiment and essentially destroy the nuclear power industry in the US. Had this not been allowed to happen, most of these plants would be gone and we'd be on to newer, safer generations of power plants by now.
Chas - The one, the only.
THANK GOD!!!
The summary does not reflect the actual severity of this condition, which, while not insignificant, is not cause to shut plants down permanently.
Not noted in the summary or article, the plants test their emergency diesel generators every month to ensure they are working. Plant trips happen, and sometimes when off-site power is not available (sometimes loss of off-site power is the cause). Someone I know who worked at the plant noted that there was always just a little bit of concern until the generators turned on, but turn on they did, consistently.
"Who are you?" "No one of consequence." "I must know." "Get used to disappointment."
"The problem wasn't the cooling system, it was the fact that the cooling system didn't work!"
No, nothing happened to the cooling system. If they are powered down thats the very definition of 'nothing happening'!
In the free world the media isn't government run; the government is media run.
So what you're saying is the next time they go subcritical for fueling or maintenance, they can install such a phase loss detection relay, and the problem is then taken care of.
Sounds like a plan!
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
That's all well and good but does nothing to reinforce the poorly-thought-out point you were [attempting] to make.
Please explain to us what an open phase is (don't go look it up). If you don't know, then you're talking from the wrong orifice.
More exactly, the motor will run a bit rougher and will lose some power (a little under 1/3rd).
They SHOULD detect this condition and take necessary measures, but it's hardly an OMG shut them all down now emergency.
Let me see if I understand what you're saying: The cooling system's power supply is not technically part of the cooling system?
Does that mean that the power supply in my computer is technically not part of my computer?
You are welcome on my lawn.
Be a nuke fanboy as much as you want, or solar or wind, but if you scream about "one true energy" and attack all the others you are evangelizing failure.
I have been on slashdot since I found it back around year 2000. I have seen the good times and bad times: I keep coming back as it is one of my favourite sites. But I was never motivated to register until now. Why? The garbage that mdsolar keeps posting about nuclear OK, scratch that, mod me down as Flamebait for my first post I don't care.
There are a majority it seems on slashdot in favour of nuclear power and the potential it has to alleviate the amount of carbon we are putting into the atmosphere. Yet rarely have I seen a pro nuclear article on slashdot. Yes we humans have changed the world. But it is not recent, we have been doing this for at least 12000 years or longer (start of the last great extinction event surely caused by natural climate change and us hunting). We manipulate and take advantage of nearby resources to improve our lives and ensure the survival of our offspring. Our society progresses, life spans get longer, overall life quality improves, we get smarter as a society. This is the cycle of human improvement. Nuclear is a viable option for electricity generation and is a part of that cycle. Energy needs are always increasing and nothing scales quite like nuclear. Expensive to design/construct yes. But fuel is literally dirt cheap. The major cost in maintaining a nuclear reactor is manpower: Training, operations, maintenance, engineering, support, but it still produces plentiful cheap baseload power that solar and wind cannot and that it does not pollute the environment like coal or natural gas does, and has capability to increase baseload that hydro cannot (most major sources of hydro have already been tapped).
I work in the nuclear industry, in the control room. My finger is literally on the keys, monitoring for any problems, issues, deviations from normal and we take appropriate action. If that means shutting down the reactor I do it. There is always a new engineering issue that crops up and we deal with it, we make it safer every time. The margins of safety always increase. The fact that there is yet another post about an issue with a nuclear plant only proves the point that the problem identified is being dealt with, not swept under the rug like in other industries. The nuclear industry is a learning one, we take the lessons from that past and improve our performance.
You are never going to see another Chernobyl, what they did was just crazy. Three mile island? we've learned from that, we have procedures in place, we have training in place, we believe what our instruments are telling us and we take action to deal with the anomaly. Fukushima? yeah we've learned about the vulnerabilities with that too and made improvements to deal with a total station blackout. It would be great if we could get new designs approved that are failsafe but since the climate in North America for nuclear is cold, we deal with the old designs. They really do work well.
Let me see if I understand what you're saying: The cooling system's power supply is not technically part of the cooling system?
Does that mean that the power supply in my computer is technically not part of my computer?
No, sure the power supply is part of the cooling system but, purely in the context of the cooling system, if its powered down then it isn't doing anything. If it isn't doing anything then, technically, in the context of the cooling system alone, nothing happened. This doesn't include side effects of the cooling system doing nothing and, therefore, having nothing happen to it.
Surely thats obvious.
In the free world the media isn't government run; the government is media run.
One of the few happy lessons from Fukushima is that defense-in-depth works -- at least to prevent mishaps from developing into the worst possible scenario.
Is this the Fukushima that's still emitting radioactive seawater? The Fukushima that's still building up tanks and tanks of more of the same?
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
No. Assuming the motors are standard 3 phase motors, even a small phase imbalance dramatically increases the amperage draw. I am not a nuclear plant engineer, but I've worked with guys who used to be, and I'm certain the motors in question are 3 phase. Loss of a phase, or a significant voltage imbalance (~20%) will cause a major amperage spike on the other two. Motor power output will be reduced, and the load will probably increase, and the motor will hit an adjusted locked rotor torque quickly. Over current protection will kick in, or, the wires will melt (or burn), or the motor windings will fail. Loss of phase is an immediate shutdown situation, either through safety systems (required by code), or if bypassed, rapid failure of the wiring systems.
Okay, I'll bite.
Chernobyl: Poorly conducted cooling system shutdown test. Result: Meltdown.
Fukushima Daiichi: Cooling system power outage and generator failure. Result: Meltdown.
Current problem: Problem leading to power short compromising cooling system: Result? You pick one of (a) problem that leads to meltdown, or (b) fix problem that compromises cooling system.
These reactors were working okay; it's just that you have to cool them or they melt down.
I made an estimation error. The problem is more severe. A 5% phase imbalance will cause a large amperage increase, and a 50% temperature rise compared to normal operation. Motors should be run within 2% of balanced. Again, loss of phase will destroy the motor very rapidly if it isn't shut down by safety or over current systems immediately.
But surely, a cooling system that powers down just when you need it reflects a design flaw. Isn't that also obvious?
You are welcome on my lawn.
It will increase the draw by 50% on each running phase unless the motor stalls. It can be bad if the motor is at the edge of it's capability when the phase drops out, but remember, these motors drive cooling pumps for a nuclear reactor, so they are larger than necessary to start with. If the reactor is scramed, they won't need to be anywhere near full capacity to keep things going.
This already happened in 2012 and it wasn't even news worthy.
No, I wouldn't rule out special interests being involved; how many engineers would turn down a nice $10 million dollar cheque from exxon or BP to just make a big huff over a minor problem?
The payoff could be enormous compared to the cost.
I wouldn't take their concerns at face value - we know too little about their motivations; there needs to be independent peer review to see if their concerns have merit or not.
I'd like to see you repeat that accusation in a cage with the engineers you're trying to put down. I think the results wouldn't be pretty for you.
Actually they're probably civilized enough to not beat you up but if looks of disdain could kill you'd be dead.
If Obama wanted to shut down the nukes how come there are 4 new reactors being built and a 5th completed right now?
One of the few happy lessons from Fukushima is that defense-in-depth works -- at least to prevent mishaps from developing into the worst possible scenario.
Is this the Fukushima that's still emitting radioactive seawater? The Fukushima that's still building up tanks and tanks of more of the same?
No it's the one that didn't kill anyone. Which is more than can be said for pretty much every other energy source humans have ever used.
Incorrect. The earthquake damaged the cooling system, and the loss of monitoring capability scuppered attempts to pump water into the system with fire engines. Basically a valve was in the wrong position and syphoned the water off, but there was no way to know because the monitoring system was broken by the earthquake and tsunami damage made it inaccessible.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
This thread addresses the actual issue.
Thoughtful
You'd report it and the electrician's permits and licences would be revoked and all past work inspected. This is a mind bogglingly stupid error.
An ad hom attack is not unexpected. As your frist post is a bit of a new low though.
With that many eyes on the lookout for good news perhaps the only reason they can't find any is because there is none. This certainly isn't news about how they fixed this issue.
It's fairer to say that Nuclear power offsets the costs of improving our lives onto our offspring who are forced to deal with the waste and decommissioned reactors.
Decreasingly so as a lot more of these plants reach the end of their service life, however it will certainly have a lasting impact.
And an appeal to authority in the first post. I'm sure you are of the highest integrity, but the industry you work in has made a habit of lying and being untrustworthy. Paid and unpaid shills are plentiful and anyone else is treated with the disdain you have demonstrated.
My ism, it's full of beliefs.
So, the control rods jammed and boron was used on an emergency basis. But control rods shouldn't jam ever. We keep nuclear power super inefficient just to avoid that kind of thing.
This situation is a risk of damage to the cooling equipment, which, if damaged, would lead to a meltdown, with or without boron. Not the same since cooling is the last line of defense.
Nuclear power does great in military propulsion at sea. It does very poorly in civilian electric generation. As we've seen, it produces catastrophic accidents, produces waste that we don't know how to manage, and is very much more expensive than anything else. But at sea, it may solve even more logistics issues going forward, strongly enhancing national security.
http://science.slashdot.org/st... The trouble is, you like civilian nuclear power generation, and that is all kinds of broken. Nuclear technology is great, essential in some applications, but is stinks in civilian power generation.
You are nothing like the airline industry who actually is a learning industry. You've learned how to PR spin and do the absolute minimum you have to do. You do the same arrogant dismissal of people's concerns and treat them like they are stupid. Fukushima proved the Nuclear Industry learned nothing from Chernobyl except how to better cover evidence and ensure the flow of information is stifled.
I used to support nuclear power, I thought it would save the world and the more I learned and asked questions the more I got labelled as "anti" unclear power.
Indeed it is this very conceit that you demonstrate that is cited in the Official report on the Fukushima accident as a key reason why Japan's unclear industry "managed to avoid absorbing the critical lessons learned from Three Mile Island and Chernobyl" and "how it became accepted practice to resist regulatory pressure and cover up small-scale accidents" like we see here.
The last thing it says about this conceited attitude is: "It was this mindset that led to the disaster at the Fukushima Daiichi Nuclear Plant. "
The attitude you display, as a professional, is no different and is a clear demonstration that the only thing you've learned from Fukushima is to point fingers and say "Not our problem".
The vulnerabilities at the Fukushima reactors were well know for decades before and GE issued procedures for ensuring that those situations would not arise for that generation reactor. The operators did not take sufficient measures to protect the reactor or the community around it.
Everything that happened in that accident was predicted by the American Society of Mechanical Engineers from an un- fuelled pressure test of that generation reactor because it was those results that led GE to devise those condition to mitigate the basis design issues that they uncovered. Those factors were not taken seriously enough by TEPCO and that is what led to the accident.
When Nuclear power fails you people claim that no one dies whilst it obliterates communities. Fukushima province was destroyed by a Tsunami however the reason it's people can't return *home* and rebuild is because a nuclear reactor spewed radioactive isotopes all over the place where that community used to exist. The same thing happened at Chernobyl.
But you guys can never take responsibility for anything, minimize everything, attack anyone who has their own concerns no matter how valid and no one has any choice but to accept that unclear power is there.
They may work well. What we have learned is that human organizational systems are not mature enough to handle nuclear power safely. Commercial reactors that are operated by for profit operators have demonstrated an unwillingness to pay for safety to be maintained.
My ism, it's full of beliefs.
It will be cheaper to fix the flaw than to shut down and fixing is an option.
I'm not sure about 'cheaper'. The plants are all roughly 40 years old at this point, and this is only being discovered 'now'? That would tend to indicate a low probability event.
Though yes, I'm sure that as the knowledge of the problem is disseminated, the relevant engineers will design fixes, to be deployed during the next appropriate maintenance cycle.
Said engineering is actually some of the problem - Because nearly every plant is, at this point, unique, the engineering for each is also unique, and therefore must be done individually, expensively.
If we were to replace those plants with, say, 2-3 standardized designs, we'd save a lot of money in the long run.
I don't read AC A human right
No. Not fools. Just having the guts to speak up.
The particular problem they identify is one I was concerned with more than 40 years ago.
You can't see an open phase by voltage in a power network with electric motors on it because they will generate the missing phase voltage.
What you need to do is look at the currents flowing in the line to see an open circuit. "Single phasing" electric motors will eventually burn them out. They are usually protected from this with heaters that detect high current on two of the remaing motor connections. They don't work very well since for a lightly loaded motor the currents are not high enough to trip, but the motor, especially the rotor will get seriously hot.
Back in the days of analog controls, I used a circuit that added the currents in A+B-2C. Simple integrator circuit with different capacitors for positive and negative directions so the phase failure relay would take about the same time for any open phase to trip. As I recall (it's been a long time) the circuits took 4 opamps, 3 to do the precision rectification for the three currents and one to do the summation and integration. I can't remember exactly how we got the signal to the relay, but it used a reed relay with two 9000 turn coils on it, one closed the relay and the other coil opposed the first and opened the relay.
End MGM. Get prospective parents of boys to Google: Men do complain
Yea, this looks like about the equivalent of a reactor scram on a navy reactor. It is just an unexpected shutdown, nothing more. Hell, the captain would cause a scram at least once a week for fun(training).
The major problem with the state of nuclear reactors these days is the regulations themselves. You can make a much safer nuclear reactor with more enriched uranium because the fuel will last for the life of the reactor vessel. This means that there is no need to open it at all until all the fuel is spent. This is how the military handles reactors. In the civilian sector you can only enrich uranium to 15% U-235 so you have to refuel the reactor multiple times before it is time to retire the vessel. This necessitates that it be made in such a way as to be easily refueled, which makes it less safe.
Do you trust everyone with an engineering degree?