Were the spent fuel pools considered a permanent location for the spent fuel?

[godai]

I'm trying to understand how they moved the rods there and if there is any way to remove them now. This photo shows how large the pool is. Looks like a small group of rods is being placed in the pool.

Does anyone know, was this pool considered to be a permanant, quick and dirty, location for spent rods? If yes, seems like a very bad idea, particularly after what's happened.

Is the yellow tank the containment vessel?

[Wilms]

1. No. It's only to cool them down enough to then dry storage them.

So even if there is a "safe" on- or off-site location to more permanently store the spent rods, they still need to take a bath for some period of time. In the case of this reactor design, that means stored in a fairly uncontained containment facility.

If there's a loss of power, the cooling stops, the water boils off, the rods are exposed, and :nuke:

-on edit-

Here's a few notes from a NYT article running today:

In 1972, Stephen H. Hanauer, then a safety official with the Atomic Energy Commission, recommended that the Mark 1 system be discontinued because it presented unacceptable safety risks. Among the concerns cited was the smaller containment design, which was more susceptible to explosion and rupture from a buildup in hydrogen — a situation that may have unfolded at the Fukushima Daiichi plant. Later that same year, Joseph Hendrie, who would later become chairman of the Nuclear Regulatory Commission, a successor agency to the atomic commission, said the idea of a ban on such systems was attractive. But the technology had been so widely accepted by the industry and regulatory officials, he said, that “reversal of this hallowed policy, particularly at this time, could well be the end of nuclear power.”

In an e-mail on Tuesday, David Lochbaum, director of the Nuclear Safety Program at the Union for Concerned Scientists, said those words seemed ironic now, given the potential global ripples from the Japanese accident.

“Not banning them might be the end of nuclear power,” said Mr. Lochbaum, a nuclear engineer who spent 17 years working in nuclear facilities, including three that used the G.E. design.

http://www.nytimes.com/2011/03/16/world/asia/16contain.html?_r=1

Repeat... :nuke:

[godai]

2. Thanks...Is there any way that they could be removed now?

Could at least some of them be removed, say from 5 and 6?

[Wilms]

4. I don't really know.

But I figure they need to sufficiently cool before that kind of handling.

[Statistical]

6. 5 & 6 are not as much of a concern.

The heat of spent fuel decays very rapidly in the first couple months. Spent fuel that is 1 second old (1 second after reactor stops) has about 7% of the thermal output (heat) compared to the reactor at full power (forced fission). This falls off very rapidly at first and then slows down. By 1 day after shutdown heat is down to 1% of peak. By one weak it is 0.2% of peak.

Fuel that is 1 year old compared to 1 month old has roughly 1/10th the heat output. Fuel that is 5 years old has only about 1/20th.

The fuel in 5 & 6 are relatively old thus the heat output is lower. They also have pumps working at 5 & 6. Even without pumps the rate it would boil off water is much slower (think of stove on loss vs high). The water level if also high in 5 & 6 making the time to respond much longer.

The reason #4 is a larger issue is that the reactor was only stopped a month ago so the fuel is very "new". Making it worse if the fact that in normal refueling operation only 1/3 of the fuel is removed. #4 was having maintenance done on the reactor core so ALL the fuel is removed. So you have an entire core's worth of very new, very heat fuel.

[godai]

8. So, will 4 become less concern (in the pool) if a week or 2 elapses?

Or is it a matter of months? I'm trying to understand if there is some logic to them trying so hard to get water into the reactors. Might they do this for months, to make the final 'tomb' a lot less radioactive? At his point, I've pretty much given up that this will be solved positively. The escaping radiation, cesium, all point to damage that can't be repaired, as far as I know.

[Statistical]

10. I don't think they have a week or two unless they get them under water.

The heat output is still very significant. Without any water to cool them (even the rods boiling water removes heat) the rods will get hotter and hotter. Eventually they will burst, ignite, or melt.

How much time? Only the people in Japan know. They would know the exact age of each fuel rod and thus can do some calculations to determine heat output. However without water it is only a matter of before the fuel ignites.

IF they can get water to the #4 spent fuel pond the amount of release will continue to be minimal. If they can't it will be similar to Chernobyl. I think in a day or two if they haven't been able to cool pond #4 they need to consider covering it in cement. The bad news is the release will still be large but at least they can reduce how much burns up and is thrown into the atmosphere.

[godai]

12. Looks like that's the hope of trying to get an electrical connection.

If the pumps work, as I understand it, the pools would fill. But, seems there is a possibility (likelihood?) that some pools are leaking from damage.

[Statistical]

14. Leak is less of a concern that inability to get water.

If the pumps work that would be huge. If they can fill the pool the radiation will drop massively. That lets workers get close and come up with alternative plans and solutions including possibly longer term transfering fuel from the damaged pond.

If they can't get water into the pond then it becomes worse case scenario and the best they can do is try to reduce the amount of radiactive material that will be released like they did at Chernobyl.

IMHO fuel pond #4 is the most severe risk to the entire site.

[Statistical]

3. No.

Spent fuel is hot (both physically and radioactively).

Water solves both problems. It provides effective cooling and is effective at blocking radiation. Also pure water can't be irradiated.
20ft of water provides a 99.999999% radiation shield.

Spent fuel no longer has fission occurs but there is decay heat as istopes created in the reactor break down. As half-lives of various isotopes past they decay into stable elements and activity decreases.

After about 5 years spent fuel is cool enough to dry cask.



In the US though most spent fuel ponds have more than 5 years worth of fuel. Sometimes they had 10, 15, 20 years of fuel. The DOE was mandated to open a spent fuel storage facility by 1980. It hasn't happened. As a result utilities were advised to plan storage around DOE transporting fuel to a government run storage facility. Many reactor sites have limited space so they keep more fuel in spent fuel ponds.

The incident in Japan illustrates why we need offsite spent fuel storage. While having an interim spent fuel storage facility wouldn't eliminate spent fuel ponds (fuel still needs to cool for 5 years) it would reduce the amount of fuel onsite and thus the amount of potential contaminants.

I am hopeful the incident in Japan will lead to a renewed effort to build at least an above ground interim spent fuel storage facility (DOE classifies interim as a facility designed to safely store fuel for 50-100 years).

[Bluerthanblue]

5. there is no "permanent location" for any spent fuel rods

that I've ever heard of. At least not any realistic permanent solution as to what to do with them.

At present, I believe the rods have to stay in cooling pools for at least 20yrs, before they can be moved to other locations.

[Wilms]

7. That's subject to debate.

Burial is an option...perhaps.

A poster on DU says Finland has done this. The Yucca Mountain idea is also about this.

[Bluerthanblue]

13. oh,

I realize that the idea of burying them has been called a "solution". But imo- (and I'm not alone in this) it isn't any responsible solution.

Back in the 80's I was active in fighting to oppose the creation of a nuclear waste "dump" (the gov. had a much less offensive name for it) proposed for several hundred acres of land which included my little town.
Seabrook Nuclear PP hadn't gone online yet, and we were fighting to keep it from going online, which would have meant that any waste buried at this site would have been produced outside our state. I was one of many who testified before the DOE in opposition of the proposed facility.
It's not a question of "not in my backyard" to me- It's the reality that this stuff doesn't belong in anyones backyard. And for us to play the denial- "worry about it tomorrow game" with this kind of dangerous material, which if we're honest- we really don't understand fully or know enough about is unbelievable.

I understand that idea of burying it is a 'solution' in some peoples mind, but it isn't in mine. I admit to not being very tolerant when it comes to this issue.

:hi:

[Wilms]

15. I'm with you on that.

What was described about Finland seemed like an ideal (if that) unlikely to be enjoyed elsewhere. They put the stuff down deep in granite right at the nuke site.

I want nukes phased out. But I may be swayed if they are able to re-use the spent fuel, on-site, rendering it less radioactive.

Let's face it. Pandora is out of the box. I think it was Einstein warning as much a long time ago.

:(

[godai]

9. I just found this site about Japan's nuclear program.

If you can get by the pro-nuclear spin, it looks educational. I'm going to read through everything to try to understand things better.

http://www.japannuclear.com/gettingstarted/gettingstarted.html

[rgbecker]

11. A clear option would be to send the waste to Guantanamo Bay.

The place of choice for storing things Congress doesn't want to deal with.