Nuclear Radiation Risk low for Alaska. (swimming, medical, rating)

[AADAD]

That is why I have been banging the drum in spite of my lack of knowledge about nuclear power. I am grateful that you and Rich do have such knowledge. my perspective as a nurse is that people who do know are alarmed and accordingly I think a thread Radiation Risk To Alaska should be started.... just my .02 but better safe than sorry IMO.

[Barkingowl]

They caught fire & burned?

[warptman]

This thread is fine. No need to make a third thread.

[AADAD]

Here is a link to the NRC Chairman statement

http://www.nytimes.com/2011/03/17/wo...uclear.html?hp

[Alaskapat528]

Originally Posted by AADAD

Here is a link to the NRC Chairman statement

http://www.nytimes.com/2011/03/17/wo...uclear.html?hp

Thanks...the article explained it.

[AADAD]

Originally Posted by warptman

This thread is fine. No need to make a third thread.

roger that. probably a good idea not to complicate things.


"When we had no fowl we ate crawdad. when there was no crawdad we ate sand."

"You ate sand?"

[Moose Whisperer]

Originally Posted by Alaskapat528

Can you please be more specific. Thanks

I will try, but it requires some technical explanation (sorry about the length).

Nuclear fuel bundles in an operating reactor produce allot of heat (obviously) due to the fission of Uranium.

When the reactor shuts down, the fission stops, however the highly radioactive fission products produced by the splitting Uranium atoms (Cesium, Strontium, Iodine, etc) continue to decay generating a lesser amount of heat. This is the “decay heat” we all have now heard of, and why Nuke plants require a shutdown or emergency cooling system of some kind even when they are "off”.

When a plant shuts down, Decay heat is initially 7% of Reactor Power (still quite capable of getting plenty hot) and gradually tapers off over the course of weeks to months.

If all power is lost at a shutdown plant and you can’t restore emergency cooling, the fuel heats up and can melt, as we have seen in this disaster.

If the fuel gets also uncovered (loses water) it will also burn - most metals burn if you get them hot enough (just take a match to a piece of steel wool if you don’t believe me).

Obviously all of this melting and burning (referred to as a “meltdown” in pop culture) destroys the physical integrity of the fuel rods and releases the highly radioactive fission products to go where they may.

In an operating reactor, this is obviously bad, but not catastrophic because everything is still inside of the Reactor Containment vessel and is prevented from escaping to the environment. This is after all what the containment is for – a final physical barrier in case of the worst case scenario.

This is what we see with Daiichi Units 1, 2, & 3.

Unit 4 however was shutdown at the time of the disaster for refueling.

This sounds good, however, the first step in the refueling process is to remove the (until just recently operating) fuel from the reactor and transfer it to the Spent Fuel Pool (SFP) – basically a big, concrete basin the size of several swimming pools, about 40 ft deep filled with water to keep the fuel cool and provide shielding since the fuel is highly radioactive. If you look at spent fuel in the pool, it actually glows an eerie blue because the radiation flux is so intense at the surface of the fuel.

The SFP has cooling systems, just like the reactor itself, to keep the spent fuel cool as the Decay Heat tapers off.

Now here’s the rub – the SFP is not within the reactor containment boundary.

In the Daiichi plant design, the SFPs sit in the reactor buildings – just a metal sided building not intended to be a pressure boundary. And due to all of the fires and explosions of late, the roof and sides of the reactor buildings have been blown off at Units 1, 2, 3, & 4.

So at U4 you now have high level, hot nuclear fuel EXPOSED DIRECTLY TO THE ENVIRONMENT. I’m sure if you flew over the site in a plane and looked down you could probably see the blue glow from the exposed fuel.

Now, this still isn’t a Chernobyl, that would require the fuel to explode and send everything into the atmosphere. That can’t happen. However, depending on how much decay heat is left, if they can’t cover this fuel quickly it will heat up and burn releasing the high level fission products directly to the atmosphere in the smoke plume.

Last I heard they were talking about bringing in water canons to shoot water on to the pool and cover it up. Problem is that spent fuel is so radioactive (now that it’s been uncovered) you can’t get within several hundred feet without getting a lethal dose of radiation.

[Frostnip]

Originally Posted by HappyNewMe

I was reading everything I could find... and just saved this one to my computer without a link. Why?
Do you know something about it? Is it a good model or a hoax, like the other map? Just say what you know, that's what we are trying to do, discuss and figure out what to expect

It's kind of hard to comment on an unsourced Russian picture that looks like it was made in MS Paint.

[Frostnip]

Originally Posted by Moose Whisperer

Last I heard they were talking about bringing in water canons to shoot water on to the pool and cover it up. Problem is that spent fuel is so radioactive (now that it’s been uncovered) you can’t get within several hundred feet without getting a lethal dose of radiation.

At the risk of sounding horribly heartless, it sounds like someone might need to pull a Spock here. Can't they hunt up a few terminally ill people who know how to operate a fire hose and want to go out as heroes or something?

[Moose Whisperer]

Originally Posted by Frostnip

At the risk of sounding horribly heartless, it sounds like someone might need to pull a Spock here. Can't they hunt up a few terminally ill people who know how to operate a fire hose and want to go out as heroes or something?

I'm sure they are asking for volunteers. At Chernobyl they also orderded some poor *******s in the army to do it, but they also had volunteers fly over the core and dump boron with helicopters. At one point they also had volunteers run up to the exposed core, throw one shovel full of sand on the reactor, then run off to suffer in a hospital after having received a near fatal dose of radiation!