Fukushima upgraded to Cat 7 TEPCO: Radiation leak may have topped Chernobyl release

[wuliheron]

Hopefully in 50 years we'll have Gen IV reactors which aren't capable of this kind of failure mode.
(Or rather, hopefully in 20 years we'll have Gen IV reactors, and in 50 years we'll have fusion reactors.)

Don't forget cheap solar as long as we're wishing. I'd love to see solar become so cheap its build into every roof shingle made for pennies extra. Still, with all the nuclear weapons and what not we'll want robots hardened against radiation that can handle such situations.

 

[wuliheron]

When the water turns to steam its still removing heat from the rods, it actually removes more heat that way.

Yeah, that's what they've been doing all along. Add water, water turns to steam, steam gets vented, add more water. The heat exchangers are gone so there isn't any alternative.

 

[Tom]

When the water turns to steam its still removing heat from the rods, it actually removes more heat that way.

Yes, but the steam also carries the radiation into the atmosphere i would think. To prevent that wouldn't the stuff need to be submerged ?

 

[the DRIZZLE]

Yes, but the steam also carries the radiation into the atmosphere i would think. To prevent that wouldn't the stuff need to be submerged ?

My understanding is that as long as the zirconium casing is intact the only radiation that is released with the steam is a small amount of tritium. Once the casing is compromised than the steam would contain the heavier radioactive elements.

 

[Tom]

My understanding is that as long as the zirconium casing is intact the only radiation that is released with the steam is a small amount of tritium. Once the casing is compromised than the steam would contain the heavier radioactive elements.

If it's on fire, how would the casing be intact ? And there are measurements of radiation coming from the plants, i assume there's some knowledge of where the radiation is coming from based on what is actually leaking.

Is the only thing that's been detected anywhere, tritium ?

 

[wuliheron]

Yes, but the steam also carries the radiation into the atmosphere i would think. To prevent that wouldn't the stuff need to be submerged ?

It's too damn hot at this point and the fire trucks can only pump so much water at a time. The shit turns to steam so fast they have to vent it or risk another explosion.

The alternative is much worse. If that radioactive material melts down into a pool of liquid metal it will destroy the containment walls and all the men will have to leave because of the radiation. It's pretty clear the containment system has already breached to some degree and that's why they had to leave the first time. Venting small amounts of radioactive material with the steam is the lesser of two evils.

 

[the DRIZZLE]

If it's on fire, how would the casing be intact ? And there are measurements of radiation coming from the plants, i assume there's some knowledge of where the radiation is coming from based on what is actually leaking.

Is the only thing that's been detected anywhere, tritium ?

Some of them probably aren't intact at this point. I don't what they've detected and what they haven't, its hard to get accurate information.

 

[rcpratt]

So much misinformation.

There is nothing that indicates that the SNF is burning. Radiation readings would be much higher. Yes, depending on the heat of the fuel assemblies, adding water would cause some to be instantly vaporized. That is good. The best way to transfer heat is by boiling water. Transferred heat = removed heat = good. If the SNF cladding is not breached (no reason to believe it is), the only radioactive isotope in the water would be N-16, with a half-life of 7 seconds. This is no different than the water that was vented Saturday/Sunday at the beginning of the crisis. It would be completely decayed by the time it got anywhere.

The amount of water required to the cool the decay heat in each reactor at this point is something on the order of 100 gpm. A garden hose is around 10 gpm. The SNF would require less cooling than that.

 

[the DRIZZLE]

So much misinformation.

There is nothing that indicates that the SNF is burning. Radiation readings would be much higher. Yes, depending on the heat of the fuel assemblies, adding water would cause some to be instantly vaporized. That is good. The best way to transfer heat is by boiling water. Transferred heat = removed heat = good. If the SNF cladding is not breached (no reason to believe it is), the only radioactive isotope in the water would be N-16, with a half-life of 7 seconds. This is no different than the water that was vented Saturday/Sunday at the beginning of the crisis. It would be completely decayed by the time it got anywhere.

The amount of water required to the cool each reactor at this point is something on the order of 100 gpm. A garden hose is around 10 gpm. The SNF would require less cooling than that.

Thanks for the corrections. I have an ME background but my nuclear experience is a pretty light.

 

[Pens1566]

Well, winds are blowing whatever is being released out to sea currently. That's supposed to switch on friday/saturday and start blowing it towards Tokyo. 3 days to get this shit under control or there is going to be a big problem.

 

[feralkid]

http://azstarnet.com/news/opinion/fitz/image_39da69b6-4f31-11e0-84f9-001cc4c002e0.html

 

[rcpratt]

Well, winds are blowing whatever is being released out to sea currently. That's supposed to switch on friday/saturday and start blowing it towards Tokyo. 3 days to get this shit under control or there is going to be a big problem.

The current release rate isn't going to impact human health.

 

[wuliheron]

Well, winds are blowing whatever is being released out to sea currently. That's supposed to switch on friday/saturday and start blowing it towards Tokyo. 3 days to get this shit under control or there is going to be a big problem.

You obviously don't get it. This isn't some child throwing a tantrum. The reactors are already wreaked and right now its the laws of physics running the show. There is no button to be pushed, no magic fairy dust to sprinkle on the cores, and no way to rush the process. The longer they can keep them from melting down altogether the better, but that's all they can do and if another containment breach occurs they won't be able to do much of that either. It will likely take weeks to months for the reaction to settle down.

 

[OrByte]

The current release rate isn't going to impact human health.

tell that to 'joe japan' over there that has to breath it.

or better yet, head on over there yourself to calm the masses.

 

[rcpratt]

Update.

UPDATE AS OF 10:00 A.M. EDT, WEDNESDAY, MARCH 16:

News reports that high radiation levels led to the evacuation of all workers from the Fukushima Daiichi nuclear power station are not accurate. Workers were evacuated for about an hour but returned to the site to continue efforts to restore safe conditions at the plant.

Restoration of electrical power to the site was under way at the Daiichi plant as of 6:00 a.m. EDT Wednesday. A temporary cable was being connected between an off-site power line and Daiichi reactor 3. Off-site power has not been available at the site since the earthquake on March 11.

Reactors 1, 2 and 3 at the plant are being cooled with seawater. There is some level of uranium fuel damage at all three units, and containment structure damage is suspected at units 2 and 3, NucNet reported.

Before the earthquake, reactor 4 had been in refueling and was completely defueled. Attempts to provide cooling water to the used fuel pool at reactor 4 by helicopter were not successful. Preparations are being made to inject water into the fuel storage pool using a high-capacity spray pump. There have been two fires inside the reactor containment building at reactor 4, but they have been extinguished. Although the reactor containment building at Unit 4 was damaged, the primary containment vessel remains intact.

At the Fukushima Daini site, all four reactors are safely shut down and cooling functions are being maintained.

 

[wuliheron]

Update.

I hope it's true, but I wouldn't bet life on it.

 

[skyking]

So much misinformation.

There is nothing that indicates that the SNF is burning. Radiation readings would be much higher. Yes, depending on the heat of the fuel assemblies, adding water would cause some to be instantly vaporized. That is good. The best way to transfer heat is by boiling water. Transferred heat = removed heat = good. If the SNF cladding is not breached (no reason to believe it is), the only radioactive isotope in the water would be N-16, with a half-life of 7 seconds. This is no different than the water that was vented Saturday/Sunday at the beginning of the crisis. It would be completely decayed by the time it got anywhere.

The amount of water required to the cool the decay heat in each reactor at this point is something on the order of 100 gpm. A garden hose is around 10 gpm. The SNF would require less cooling than that.

I don't think that is entirely accurate. The N-16 with a half life if 7 seconds, that is with pure water. I believe they are using seawater with all the salts and dissolved metals. I don't know what gets released with seawater.
My guess and it is only a guess, is this has been the problem with radiation for the crew.
What do you think?

 

[rcpratt]

I believe the water that was or is boiling off of the spent fuel pools was the original deionized, demineralized water. I assume that as they focused on cooling the reactors, no water was pumped into the pools. It would have taken several days for the water in pool #4 to reach saturation.

I have not heard of seawater being pumped into the pools. There was talk of helicopter drops yesterday, and now a high-capacity spray pump has been brought in.

I still think the suppression pool breach is responsible for the majority of the radiation release, but that is just my educated guess.

 

[frostedflakes]

I thought I read that there is other stuff than N-16 being released. None of the radioactive isotopes are very long-lived, though, most had half-lives on the order of seconds or hours I believe.

 

[rcpratt]

I thought I read that there is other stuff than N-16 being released. None of the radioactive isotopes are very long-lived, though, most had half-lives on the order of seconds or hours I believe.

It surely is, as seawater that had been used to cool the reactor was vented to the suppression pool which later breached. I'm just not sure that there was seawater in the spent fuel pool, my guess is no.

 

[skyking]

ahh OK.

 

[Pens1566]

You obviously don't get it. This isn't some child throwing a tantrum. The reactors are already wreaked and right now its the laws of physics running the show. There is no button to be pushed, no magic fairy dust to sprinkle on the cores, and no way to rush the process. The longer they can keep them from melting down altogether the better, but that's all they can do and if another containment breach occurs they won't be able to do much of that either. It will likely take weeks to months for the reaction to settle down.

Uh, I think you're reading too much into "get this shit under control" copernicus.

 

[wuliheron]

Uh, I think you're reading too much into "get this shit under control" copernicus.

Then enlighten me Plato. Just what did you mean by "get this shit under control"?

 

[Pens1566]

Then enlighten me Plato. Just what did you mean by "get this shit under control"?

What I was referring to, and apparently everyone but you understood, was that at the current rate this would/will be a full on meltdown by the time the weather changed. Next time I'll use pictures ..

BTW, shouldn't you be building titanium bike frames out of seawater instead of taking innocuous comments way to seriously and attacking people for them???

 

[smoothvirus]

Now is the time to start worrying, this is a full nuclear release.

1 sievert per hour is fatal. (1 sievert is a fatal dose)

They really fucked this up to let it get this bad.

While there's no doubt this is a very serious incident, unless you live in Japan there's really no need to worry about radiation coming from the plant.