Faults could affect TVA Nukes

[pompey]

So the disaster in Japan has sparked some discussion of the future of nuclear power in the US - including the TVA reactors:

www.timesfreepress.com/news/2011/mar/17/quake-faults-could-affect-sequoyah-watts-bar/

[fishpants]

Er, okay... core damage potential from earthquakes:

Sequoyah: 1 in 19,608
Watts Bar: 1 in 27,778
Browns Ferry 1: 1 in 270,270
Browns Ferry 2 & 3: 1 in 185,185

...and the odd that these numbers are pretty much made up and someone just pulled them outta their ass: 1 in 1

[ssmynkint]

The odd.

[pompey]

Mar 17, 2011 20:03:17 GMT -5 fishpants said:

Er, okay... core damage potential from earthquakes:

Sequoyah: 1 in 19,608
Watts Bar: 1 in 27,778
Browns Ferry 1: 1 in 270,270
Browns Ferry 2 & 3: 1 in 185,185

...and the odd that these numbers are pretty much made up and someone just pulled them outta their ass: 1 in 1

And I estimate that 1 in 1 is also the "odd" that the people that made those estimates have a deeper understanding of nuclear risk than you do.

[fishpants]

/me bows and begs forgiveness for the lack of a simple "s"...

...but quite frankly the ability of US government agencies to play with numbers accurately is shit.
www.fotuva.org/feynman/challenger-appendix.html

But why argue? Can we get the actual NRC data to look at?

[Tsavodiner]

If we have Japan-style cataclysms here I'll worry more about cannabalism....

[Justin Thyme]

Those odds aren't defined well enough for me to really comment on. The strongest earthquake along the fault line in question has been a 4.6. The plants are designed to withstand greater than a 5.0 earthquake and I think it is actually like a 5.6, a magnitude higher than the strongest quake recorded on that fault line. The Fukushima plants were designed for a 7.something quake and actually held up well to a 9.0 quake, it was the resulting tsunami that took out their cooling systems and caused the problems. I don't think any of TVA's plants have to worry about tsunamis or storm surges. So are the odds that of a strong enough quake hitting those reactors to damage the core or are the odds those of the reactor's core being damaged should an earthquake strike at the reactors? It's a really poorly written article.

[pompey]

Mar 18, 2011 5:24:10 GMT -5 Justin Thyme said:

I don't think any of TVA's plants have to worry about tsunamis or storm surges.

As you noted, though, it was not the earthquake, the tsunamis or storm surges that caused the problem - it was the loss of cooling capacity that accompanied a massive power disruption. TVA plants don't have to worry about tsunamis, but massive power disruptions can come from many different sources other than simply rising seawater.

So are the odds that of a strong enough quake hitting those reactors to damage the core or are the odds those of the reactor's core being damaged should an earthquake strike at the reactors?

The article is clear on this: "At Sequoyah, about 20 miles north of Chattanooga, the chances of an earthquake causing core damage at each reactor are 1 in 19,608". In your formulation, that's, "the odds those of the reactor's core being damaged should an earthquake strike at the reactors". We're talking actual damage - not conditions that might create damage.

It's a really poorly written article.

The article is fine. I'd like to see references to actual sources and more depth (and I plan to use it as the starting point for more research), but in general the article was quite informative and timely, especially given what I imagine was a very aggressive editorial deadline.

[gridbug]

TVA plants don't have to worry about tsunamis, but massive power disruptions can come from many different sources other than simply rising seawater.

TVA did take into consideration the possibility of Watts Bar or Chicamauga dams breaking. Their emergency generatiors are placed high enough to be safe from that sort of flooding.

[pompey]

Mar 18, 2011 11:48:30 GMT -5 @gridbug said:

TVA plants don't have to worry about tsunamis, but massive power disruptions can come from many different sources other than simply rising seawater.

TVA did take into consideration the possibility of Watts Bar or Chicamauga dams breaking. Their emergency generatiors are placed high enough to be safe from that sort of flooding.

How high are they placed?

There are other causes of massive power disruption besides flooding.

[Deleted]

I find it ironic that a plant designed to produce electric power has no electric power.

[gridbug]

How high are they placed?There are other causes of massive power disruption besides flooding.

I was just responding regarding the closest thing to a tsunami they have to worry about. I forget just how high they said they are placed.

[coffeeshooter]

Mar 18, 2011 5:24:10 GMT -5 Justin Thyme said:

Those odds aren't defined well enough for me to really comment on. The strongest earthquake along the fault line in question has been a 4.6. The plants are designed to withstand greater than a 5.0 earthquake and I think it is actually like a 5.6, a magnitude higher than the strongest quake recorded on that fault line. The Fukushima plants were designed for a 7.something quake and actually held up well to a 9.0 quake, it was the resulting tsunami that took out their cooling systems and caused the problems. I don't think any of TVA's plants have to worry about tsunamis or storm surges. So are the odds that of a strong enough quake hitting those reactors to damage the core or are the odds those of the reactor's core being damaged should an earthquake strike at the reactors? It's a really poorly written article.

The New Madrid fault line near Memphis had earthquakes in the 6.0-80 range back in the early 1800s. Legend has it that the Mississippi River ran backwards for a time.
If it happens again, this area will definitely suffer serious damage. We can only hope that TVA has their act together and that the plants in Missouri can withstand another earthquake.

[frayne56]

My take, much ado about nothing and little more than a knee jerk reaction. Yes, the event in Japan is horrible and unheard of in scope and severity but the bottom line is, we need nuclear power generation and with any endeavor there are risks. I am willing to take those risks in order to get off fossil fuels. Ideally if we could satisfy our energy needs with wind, solar, geothermal and hydro renewable sources that would be great, unfortunately we can't. The nuclear industry record is pretty darn good all in all as compared to coal and fossil fuel power generation.

Does one horrible vehicle accident on I-75 stop any of us from driving ? Nope, neither should an event like what is happening in Japan should deter us from using and expanding our nuclear power generation.

[pompey]

Does one horrible vehicle accident on I-75 stop any of us from driving ? Nope, neither should an event like what is happening in Japan should deter us from using and expanding our nuclear power generation.

This is a false equivalency. You are comparing a high-frequency, low-impact event with a low-frequency, high-impact event. A wreck on I-75 affects a number of people ranging from 1 to the single digits. A nuclear event affects many thousands if not millions and costs many, many millions. You bet your boots that if wrecks on the highway had that kind of global impact, they would be looked at VERY differently.

The question is : given the risks of nuclear power, can we afford it? I think that the Japan example (which is far from resolved at this moment) is cause for concern and more analysis than, "well, its all we got". That kind of fatalism could prove to be extremely foolish if not leavened with a good, solid creative analysis and discussion of where we need to go from here.

[frayne56]

Your point is well taken but given the total of fatalities on our highways just in the US since the advent and use of nuclear power, nuclear power is much safer. The Japanese problem will be resolved eventually by entombing the reactors in sand, lead, concrete or a combination of all three and the loss of life will probably be less than the US experiences on our highways over a holiday weekend.

[el Gusano]

More people died at Chappaquiddick Island than Three Mile Island.

[mikeydokey]

it's not my fault

[Justin Thyme]

Mar 18, 2011 12:52:39 GMT -5 @yodanbr2 said:

I find it ironic that a plant designed to produce electric power has no electric power.

The plant was designed to automatically shutdown on detection of a significant seismic event. That drops out power production. Emergency generators were suppose to cut on to continue powering the cooling pumps. The tsunami wiped out that capability. Perhaps it would have been better to keep the reactors going. Then they would have had power to turn the cooling pumps. Everything I'm reading says the plant suffered no significant earthquake damage; all the damage was caused by the tsunami.

[pompey]

Immediate loss of life is not the only measure of severity in a crisis like this, and limiting the impact assessment to a mere short-term body count is not a reasonable way to look at this. Radiation has longer-term negative effects that can last for decades and affect large numbers of people.

[frayne56]

Mar 19, 2011 18:22:38 GMT -5 pompey said:

Immediate loss of life is not the only measure of severity in a crisis like this, and limiting the impact assessment to a mere short-term body count is not a reasonable way to look at this. Radiation has longer-term negative effects that can last for decades and affect large numbers of people.

I agree but how do you quantify ?

[pompey]

Increase in cancer deaths, cancer rates, birth defects, environmental remediation costs, etc.

[frayne56]

Mar 20, 2011 9:06:42 GMT -5 pompey said:

Increase in cancer deaths, cancer rates, birth defects, environmental remediation costs, etc.

Easier said than done due to lifestyle and other environmental factors.

[pompey]

Mar 20, 2011 9:46:06 GMT -5 frayne56 said:

Mar 20, 2011 9:06:42 GMT -5 pompey said:

Increase in cancer deaths, cancer rates, birth defects, environmental remediation costs, etc.

Easier said than done due to lifestyle and other environmental factors.

I am confident that it can be done.

[cadillacdude1975]

i say that there should be mandatory backup tests of all systems quarterly. complete tests on the generators and all that jazz.

[mikeydokey]

Mar 20, 2011 20:00:37 GMT -5 cadillacdude1975 said:

i say that there should be mandatory backup tests of all systems quarterly. complete tests on the generators and all that jazz.

There is no way we should wait 25 years between testing the systems.