Posted on 08/23/2011 12:42:13 PM PDT by matt04
A nuclear power plant located in Louisa County, the epicenter of the earthquake in Virginia, has shut down.
The North Anna Power Station, operated by Dominion Power, has two reactors. The plant declared an "unusual event" in the wake of the 5.9 magnitude quake, which is the lowest stage on the plant's emergency scale.
As a result, the plant has been shut down.
The AP reports the plant is being run off of four emergency diesel generators, which are supplying power for critical safety equipment.
Nuclear Regulatory Commission spokesman Roger Hannah says the agency was not immediately aware of any damage at nuclear power plants in the southeast.
(Excerpt) Read more at nbcwashington.com ...
“The AP reports the plant is being run off of four emergency diesel generators, which are supplying power for critical safety equipment.”
WHAT? The Enviro-Weenies are gonna be all over THIS! Using Fossil Fuels to cover for a Nuclear Plant shut-down?
Heads. Will. Explode.
Oh. Wait. Never mind...
Backup Generator Cooling Nuclear Power Plant Shutdown By Virginia Quake Fails
There is nothing to fear with a report of an Unusual event. It’s just what it sounds like, an event that doesn’t normally happen. The NRC wants records kept of everything and to have them and the public informed of any things “out of the normally expected parameters.”
Things like tornado warnings within 10 miles of a nuclear power plant can activate an “unusual event” notification.
Here is a little guide to think about....if you were exposed to 400 Rems or more of radiation, you would be facing possible death. In a typical year you will recieve from the sun and background radiation about .003 Rem. Occupational Nuclear Power Plant workers are only allowed to recieve a maximum of 5 Rem per year.
Exel Energy is an outstanding company and I’m sure that the Monticello plant is in excellent hands. That being said, with the above guide you should be able to judge, based on accurate reporting, that if an accident were to happen, what your potential dangers were.
Hope that helps.
P.S. I work in the Nuclear power industry. I have for over 25 years and I haven’t gone over 5 Rem total in my lifetime. Nuclear plant workers are actually quite concerned about not just protecting themselves but their surrounding communities, which contains their families. If you have any questions, I’m sure Monticello has a place where you can contact people with your concerns.
Have you heard anything about Millstone or Vermont Yankee? I know tremors were felt up that far north.
NRC is Monitoring North Anna and other Nuclear Plants on East Coast Following the Earthquake
Oops, correction to my last post....NOT .003 Rem but .3 Rem. The point was that you are exposed to radiation on a daily basis, but it is very small. Radiation at a nuclear power plant is higher but extensively monitored to not only protect the surrounding communities but the workers themselves.
A couple of the problems I had with the Japanese disaster was threefold:
1) Many in the press are ignorant about even the basics of Nuclear power/energy, therefore bad or misleading reporting
2) There are many different labels for measuring Radiation (Rems, Grays, Roentgen, Sieverts, etc.) that it gets confusing. http://www.stevequayle.com/ARAN/rad.conversion.html
3) Most of the public doesn’t have a basic understanding of nuclear power.
How big are those generators? I have heard the press talk about them, both in this case and earlier in the year when one was surrounded by the flooded Mississippi river.
A couple of things to keep in mind...
One, if the NRC thinks for an instant that a power plant is trying to hide something, they will “rip them a new one” through inspections and/or fines. Therefore, plants will generally report things that may not be a problem, but may lead to a problem or not reporting the event may be percieved as “hiding a problem”.
So, when the Emergency Guidelines for the plant say something like, “An earthquake felt in plant with significant magnitude for SUSPECTED structural or equipment damage, then issue an Alert” you can bet they will issue an Alert, EVEN if there is no immediate signs of structual or equipment damage. (BTW, the difference between calling an Unusual event and an Alert is the “suspected damage aspect”.)
The NRC likes to see plants operating with that kind of mindset. The plants that issued their alerts or unusual events have procedures and guidelines to check that everything is good and to get back on line.
As a side note, this is more notification then what you get from other large industrial plants which could pose a risk to its workers and surrounding communities. When the coal plant next door has an over pressure condition in one of it’s boilers, you never hear about it, but in a Nuclear power plant you will.
One other thing I forgot to mention, operational power plants usually have an NRC representative on site, so they are technically always under observation. There are also NRC monitoring control rooms in which plants report their status to. So being “observed by the NRC” isn’t something out of the ordinary. It’s something that is done on a constant basis.
The alert was issued due to loss of external power. That was a fairly obvious problem.
Apparently not. And you are preaching to an ex Navy nuclear submarine officer by the way.
I don’t know exactly how the plant in questions set up is but I can guess based on the plants I’ve been to.
The normal source of power is the grid.
The next source of electrical power would be Diesel generators.
The next would be battery banks with alternators.
Any number of things can trigger an unusual event or alert. If one of the back up generators failed to auto start, that could be reason enough. If one of the back up generators fuel supply was compromised below a prestated amount, that could cause an alert. If a normally opperation breaker, which supplies power from the grid fails to close or open properly, that could cause an alert issue. I’m serious that there could be literally hundreds of possible sinarios in which “Normal operational parameters” were not met and the NRC had to be notified.
Should a person be aware of what’s going on? Absolutely.
Should a person be scared right now? NOT at all.
Let me go back to the Radiation limits as an example. Doctors don’t really see any changes in people until around 25 Rem (some changes in the blood count). It’s not until around 400 Rem that death is possible. So with that as a guide line the NRC (formerly the AEC) said that they didn’t want workers to get anything even close to 25 Rem, so they set 5 Rem as a limit. Plants then set their local limits as less then 5 Rem (usually 4 Rem) so that they didn’t run the risk of even getting close to the NRC’s limit.
The same is true with every other aspect of Nuclear power. If the NRC says you need two backup sources, plants will have 4 or more just to fail on the safe side of things. And it isn’t just making sure they have 4 Emergency Diesel Generators, but enough fuel to run each one for enough time to get more fuel sent from an outside source. Most plants have reserves of fuel to last for days without outside assistance. That also goes for spare parts for Emergency sources. Those things are already bought and stored in warehouses.
I’m not saying that anyone should just automatically trust completely what a plant is putting out, but realize that they too are interested in staying safe for their health and safety as well as the surrounding communities. Besides that there are hefty fines and possible imprisionment for creating or covering up a release of dangerous radioactivity.
I would say trust, but verify, and also realize that the people that work at these plants have the same or greater concerns for their lives as those people who live around the power plants. Panic and unjustified fear is not justified here at this point. IF the plant starts calling for evacuation from around the plants, THEN be concerned, but realize again, if the limit is 500 DAC/hour then the danger is going to be around 1000 DAC/hour and the evacuation will be called at 50 DAC/hour.
(DAC=Derived Air Concentration, which is essentially saying if you breath in 1 DAC of something for 2000 hours {about 1 year of work} you could receive an internal dose of 5 Rem.)
No, an appropriate precaution, assuming the plant was designed to the worst-case earthquake environment for the area, which might have been a 7.0. A 5.9 EQ would have a a chance of being a foreshock to be followed by a 7.0-7.5 EQ near the plant design limits. If you look at the Japan EQ, there were 7.0 level foreshocks that should have led the Fukushima Daiichi ower plant to be fully shut down as a precaution. Would not have prevented all that ultimately happened, but some.
I would not be surprised if the cautionary protocols at US nuke plants has been tightened accordingly. Better to have your pizzas thaw a bit than having to deal with the irrational radiation panics that the media lived on for a good while after the Japan EQ.
It was the terminology that struck me as funny. "Unusual event". They had an EARTHQUAKE. The systems were shut down, I assume as a precaution more than anything. Especially in light of what happened at Fukushima.
"Unusual" conjured up images of a Homer Simpson-esque mishap...
Thanks for the additional info though. :-)
Curious as to why this is still #1 in Breaking News. A shutdown is Standard Operating Procedure and the breaking news part would be if it DIDN’T shut down. Are we fear-mongering or is there an unreported issue going on here? Just curious
Thanks for the replies, particularly in light of your experience in the field.
Many interesting design issues in the back-up power systems area, especially in light of Fukushima. It was interesting that they fired-up a fifth generator to replace the one that went down. I’m still curious about whether the load requires two spinning per reactor, or whether they just need one and spin the other for back-up. In my ignorance spinning for back-up seems odd in light of low latency for them to come on line, wear and tear and fuel consumption, but I don’t know enough one way or the other.
I was wondering if the cause of the failure to the one genset was any threat to the others. Here it was a cooling system that leaked. Was that caused by the quake or some other cause common to all gensets, or was it isolated to that one? To what extent were the other gensets stressed or threatened by the quake? Obviously, they got 4 working, but was it a close call? Interesting stuff.
Thanks for keeping the lights on!
Neither Millstone nor VY reported a UE to NRC yesterday. See http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2011/20110824en.html
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