Are rooftop water pools covering nuclear rods a typical design in the US?

[dkf]

Some woman on CNN says this is a typical design but didn't clarify who has these. We can't possibly be this vulnerable in the US can we?

Then some other guy says certain plants have been grandfathered in so does that mean they don't have all the latest safety requirements? Are you kidding me?

Is it any wonder no one wants one of these plants in their backyard? I am still incredulous.

[Lucinda]

1. I have heard that a few dozen of ours are the same design

Cant give you a link, it may have been at one of the CNIC pressers I watched.

[Tx4obama]

3. I think I heard the number was something like in the 40s or 60s on the news. n/t

[willing dwarf]

2. Incredulous?

"We can't possibly be this vulnerable in the US can we?" -- Um, I wish you well, but I've got to say, perhaps you haven't noticed what runaway capitalism has done in this country, but those of us who have seen how greed runs the game can't possibly be surprised by any design which will reduce cost and increase profit for corporations like GE. Plus with underpaid workers building these things on job sights round the country, shoddy workmanship would be no surprise either. In my opinion, the real surprise is that we've managed to survive without incident for so long.

[Tx4obama]

4. Seems like everyone should have been hollering about this after 9/11

the thought that a plane could hit the top of buildings that have spent nuclear rod pools is very frightening!

Wonder how many people even knew that spent rod pools are located towards the top of those buildings.
I didn't until a few days ago.

[dkf]

7. I heard them talking about it but I didn't get what that meant til CNN showed an illustration.

[Ian David]

5. I just heard from an expert, and they are NOT on the roof above the reactor.

They are in the containment building, above and to the right of the reactor.

Via terrypritchard http://twitter.com/terrypritchard

Spent Fuel Pools at Fukushima

| by David Wright | nuclear power | nuclear power safety | Japan nuclear |

Because of their high radioactivity, fuel rods continue to produce very significant heat even after they are no longer useful for generating electricity and are removed from the reactor core. Such “spent fuel” rods need to be continually cooled for many years to prevent them from heating to a level where they would suffer damage.

To cool the rods after they are removed from the reactor core, they are placed on racks in a spent fuel pool that circulates cooled water around them. This water is circulated by pumps that are run using electricity from the power grid. Typically these pumps do not have backup power from deisel generators or batteries, so if power from the grid is interrupted, as it is in the case of the Japanese earthquake, they will stop operating.

Once the cooling pumps stop, the water in the spent fuel pools will begin to heat up and will eventually start to boil off. The pools are typically 45 feet deep with the fuel rods stored in the lower 15 feet of the pool, so 30 feet of water would have to boil off before exposing the rods. That could take several days, so this issue may only be appearing now.

The pool at Fukushima Dai-Ichi Unit 4 is a particular problem since the fuel rods in it were only removed from the reactor core during a refueling of the reactor in December 2010. Therefore, they still have a very high level of radiation and are generating more heat than the spent fuel at the other reactors at the Dai-Ichi site.



More:
http://allthingsnuclear.org/

[madrchsod]

6. cooling ponds......

they are not on the roof

[Tx4obama]

8. I have not heard anyone ever say they were ON the roof....

they are located 'towards the top of the building'.
Those building are like six stories high, the pools are about four-five stories up.

[reformist2]

9. Paul Gunter says there are 36 reactors in US just like the ones in Japan.

1:40 in

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=385&topic_id=563757&mesg_id=563757

ps. They're not "on the roof", but on the top floor. Which really isn't thst much better.

[Gabi Hayes]

10. building four no longer has a roof; that pool is exposed. here's what it looks like:

the reactor itself (still inside its containment shell) is right in the middle, exposed to the outside.

the cubically shaped building surrounding the containment shell is basically a "tin roof," as described by commentators on CNN a few minutes ago

as you can see, the ''tin roof,'' and the upper walls have blown off, leaving only the skeleton

with radiation levels in Tokyo quadrupling, and maximum working time of 3-4 minutes for emergency workers (they're all living ghosts now, anyway), and the water no longer covering the spent rods in Reactor Four, things are going to get out of control

the worst is yet to come, and it's going to have worldwide ramifications, not the least of which will be economic. Chernobyl is going to look like Eden compared to what's going to happen to Japan

[enough]

11. The Peach Bottom plant near me has this same design, and has been operating for

more than 40 years. The NRC has licensed it to go on till 2033, and they are talking about letting plants operate beyond the SIXTY-year limit. These are plants originally intended to operate for 40 years.

And all this time they are accumulating spent fuel rods.

Insane is the word for sure.

By the way, this plant is not far from Baltimore.

[liberalmuse]

12. I never thought I'd say this, but Yucca Mountain is looking pretty good right now.

If so, I hope they rethink this.

[reformist2]

15. Yeah, as a tomb for the nuclear industry!

[marions ghost]

13. 23 similar reactors in US

Japan's nuclear crisis is drawing attention to aging U.S. reactors, especially the 23 most similar to reactors at the Japanese plant where workers are racing to avoid a full-scale meltdown.

Eleven U.S. utilities, including industry giants such as Southern Co., Energy Corp. and Exelon Corp., own similar reactors in 14 states. Most of them are operating beyond their initial 40-year licenses and have been granted 20-year extensions by federal regulators.

www.wsj.com

--------------
Anyone who takes the time to read up on the state of the reactors in the US and the inadequate safety and evacuation procedures around them would be amazed.

[Statistical]

14. Different reactor designs put the cooling pond in different places. 3 examples from worst to best.

There are 23 reactors in the US (GE BWR-3 MK I) that are identical to the reactor in Japan. The "rooftop" spent fuel garden was GE idea to save money. See if you had the cooling pond next to the reactor containment building would need to be larger. Larger containment = more cost. So squeeze it in up there on top of the reactor. Everything about the MK I was to cut cost.



Most designs (before and after GE MK I) put the cooling pond on the ground inside containment "next" to the reactor.



The entire containment building is flooded to a level above the reactor. The reactor is opened and fuel is transfered from the cooling pond (at ground level) and the reactor. Not the best photo but the big thing in the middle is the fuel handling machine (all this is done remotely). The reactor is at the top, the cylinder is a fuel rod being removed. The fuel pond is at the bottom of the photo. Once refueling is done the reactor's head (cap) is put back on and containment is drained (leaving only water in the cooling pond.





Even later designs move fuel to a seperate building called a fuel handling building, mainly because reactors got larger and went from 2 cooling loops to 4 cooling loops. Notice the "tunnel" that connects the two buildings. There is a remote operated "trolley" that moves fuel from one building to the other.