N. Anna Nuclear Plant: Quake's jolts were double nuke plant's design

[kristopher]

Quake's jolts were double nuke plant's design
By Wendy Koch, USA TODAY


Parts of the North Anna Power Station in Mineral, Va., 11 miles from its epicenter, endured jolts equal to 26% of the force of gravity (0.26g) from some of the vibrations unleashed by the quake, said Scott Burnell, spokesman of the Nuclear Regulatory Commission.

An NRC document says the reactors' containment structure was built to withstand 12% of the force of gravity (0.12g.) Dominion, the plant's operator, says parts of the plant can handle up to 0.18g.


"It's the things inside the buildings that may have been shaken more than the design called for," Burnell said, adding the buildings themselves appear to have been less affected. He said the analysis is based on a seismograph reading taken about 30 miles away by the U.S. Geological Survey.

Whatever the final numbers on shaking or ground motion, the plant withstood the jolts, Burnell said, indicating there's a "great deal" of safety margin. "That margin was certainly enough for North Anna this time."

Then ...


http://www.usatoday.com/tech/science/environment/story/2011-09-07/Quakes-jolts-were-double-nuke-plants-design/50304434/1


See also http://www.ucsusa.org/nuclear_power/

[Tesha]

1. Nuclear power: "Too cheap to meter" and "safe as mother's milk" (until it's not). (NT)

[sam11111]

germany tossing away ALL nuke plants!

Well... Maybe not tossing. But getting rid somehow.

"Man is not wise enough to handle uranium. All uranium back in the ground"

[sam11111]

3. 9.1 quake possible anywhere. Windmill or nuke the better neighbor?

Windmill falls over (heh)

[TheWraith]

9. And to do so, they're building 17 new coal plants.

To spew millions of tons of CO2 into the air, where they previously had a carbon-free way of generating electricity.

Yes, brilliant idea.

[FBaggins]

10. Now now... let's not oversimplify.

They're also burning more coal at existing plants... reopening idled 50+ year old coal plants... and importing nuclear power from neighboring countries.

And if it gets exceptionally cold this winter, they're still not sure that they'll be able to keep the lights on. Good thing they burned all that coal in prior decades so now global warming can reduce the chances that winter will be unusually cold.

[sam11111]

2. dup

Nt

[bananas]

4. They didn't mention this at nuclearshillscollective.com

can't imagine why...

[kristopher]

5. Do you happen to have the tepco release detailing the measurements at Fukushima?

Tepco released a table with the standards of the plants and the actual forces they had been subject to. I had it on file but can't locate it.

What I remember specifically was that the force was far lower at the plant than the 9.1 recorded at the epicenter, and that the maximum amount it had exceeded standards by was only 26%.

[FBaggins]

6. How about the other plants in Japan?

There were a number of reactors that were comparably close to the epicenter.

Regardless, that's just a game you're playing. As if five seconds at twice the design-level acceleration at one frequency is worse than several minutes of shaking at a different frequency just because it only exceeded the design-level by 26%.

The question also ignores that earthquakes aren't the only factor in a design. If there are five factors that go into the size of a given bolt, you're going to pick the bolt that satisfies all five factors. If you're designing for an 8.0 earthquake in Japan, that factor is likely to be the one that results in the largest bolt. While the size of the same bolt when designing a plant for a 6.0 quake would be determined by a different factor.

[kristopher]

7. An earthquake barely exceeding design standards caused the meltdown of 3 reactors...

Screw your spin.

[FBaggins]

8. Nope. It didn't.

The spin is all yours.

There has been ZERO evidence that the earthquake caused the meltdowns (except to the extent that it also caused the power failure and tsunami) and the evidence that you're conveniently dodging more than proves it didn't.

What an ODD coincidence that several reactors were hit by design-basis earthquakes without serious impact (as has been the case for a number of other earthquakes in Japan), yet three sitting right next to each other all melted down. What on earth could explain that? Could there be something that they shared in common that the others didn't?

Nah.

And of course now we have some evidence that North Anna was technically hit with a beyond-design earthquake... and so far it looks like a caulk gun will fix it (though no doubt the "almost lost Nebraska" team will also tell us that we almost lost Virginia (and D.C.!!!)

[bananas]

11. Is this it?

See tne link in this post: http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=303012&mesg_id=303333

[kristopher]

12. Yes, that's it.

This is the link.
http://www.tepco.co.jp/en/press/corp-com/release/11040103-e.html
The motion at the site was only marginally more than design specs.

Also see this article, which looks into the amount of damage done by the earthquake before the tsunami struck.
http://www.independent.co.uk/news/world/asia/the-explosive-truth-behind-fukushimas-meltdown-2338819.html

The explosive truth behind Fukushima's meltdown
By David McNeill in Tokyo and Jake Adelstein

...if the earthquake structurally compromised the plant and the safety of its nuclear fuel, then every similar reactor in Japan may have to be shut down. With almost all of Japan's 54 reactors either offline (in the case of 35) or scheduled for shutdown by next April, the issue of structural safety looms over any discussion about restarting them.

Plant operator Tokyo Electric Power Co (Tepco) and Japan's government are hardly reliable adjudicators in this controversy. "There has been no meltdown," government spokesman Yukio Edano repeated in the days after 11 March

...Mitsuhiko Tanaka, a former nuclear plant designer, describes what occurred on 11 March as a loss-of-coolant accident. "The data that Tepco has made public shows a huge loss of coolant within the first few hours of the earthquake. It can't be accounted for by the loss of electrical power. There was already so much damage to the cooling system that a meltdown was inevitable long before the tsunami came."

[bananas]

13. nuclear plant designer: "a meltdown was inevitable long before the tsunami came"

...Mitsuhiko Tanaka, a former nuclear plant designer, describes what occurred on 11 March as a loss-of-coolant accident. "The data that Tepco has made public shows a huge loss of coolant within the first few hours of the earthquake. It can't be accounted for by the loss of electrical power. There was already so much damage to the cooling system that a meltdown was inevitable long before the tsunami came."

Of course, the anti-science pro-nuclear advocates are in denial about this.

A PR Guide for the Nuclear Industry: Deny, Deny, Deny!
"What earthquake? Where? When?"
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=385x583589