Can someone explain in plain language what all these meltdowns in Japan mean?

[The Backlash Cometh]

Does this just mean that Japan now has three or four hot spots where no one can visit? Does it mean a gradual poisoning of the entire world? Will there be a China syndrome effect where it will go to the core of the Earth and bring on the Rapture on May 21st?

What does it mean?

[flamingdem]

1. I googled for the basics and found this:

Reported from abc NEWS, Scientists said that even though the reactor had stopped producing energy, its fuel continues to generate heat and needs steady levels of coolant to prevent it from overheating and triggering a dangerous cascade of events.

They go on to say, “Up to 100 percent of the volatile radioactive Cesium-137 content of the pools could go up in flames and smoke, to blow downwind over large distances,”

“Given the large quantity of irradiated nuclear fuel in the pool, the radioactivity release could be worse than the Chernobyl nuclear reactor catastrophe of 25 years ago.” said Kevin Kamps, a nuclear waste specialist.

Fukushima I (there are two plant locations) is one of the 25 largest nuclear power stations in the world.

How would a nuclear plant meltdown unfold?

* Control rods are driven back down into the core upon emergency (if rods don’t make it all the way… trouble)
* The coolant (water) could cease if backup systems fail (electricity, pumps, generators, batteries)
* Reactor continues to produce heat
* Numerous venting valve systems would release pressure above ~1,000 psi into containment vessel

WE ARE HERE:
* Eventually the uranium fuel encasement metal will melt (2,200 deg F)
* Radioactive contamination then released into the reactor vessel
* Radiation escapes into an outer, concrete containment building
* Radiation escapes into the environment as radioactive Fallout.


Not only would such a disaster be horrible for the local region and Japan, but other countries, namely the U.S. could be effected next by airborne fallout of radiation particles, the magnitude of which is yet to be determined.

[The Backlash Cometh]

3. So they're trying to keep it from exploding because it will add radiation

to the wind currents?

[flamingdem]

4. Regardless it will spew radiation locally for a very long time

and depending on the wind patterns this could severely impact Tokyo, over here we'll be getting fallout. The issue is bioaccumulation over a long period, especially an issue with grass/cows/milk. The immediate issue of course is for the Japanese, their children in particular

[The Backlash Cometh]

5. I predict in five years, that the right-wingers will be adding the Japanese

to their anti-immigration programs.

[JuniperLea]

6. That's what the Regressives do...

They would put Japanese people BACK on their anti-immigration list of undesirables.

It's sickening that you are so right.

[The Backlash Cometh]

7. I wouldn't mind being proven wrong every now and then.

[JuniperLea]

8. I know... it sucks to be right sometimes...

Sorry for pointing it out.

:hi:

[CoffeeCat]

13. I've also read that Fukushima has ten times more...

...nuclear material than Chernobyl ever had.

The potential disaster of Fukushima is our worst nightmare. The fact that they've been unable to
stop the reactions/heat after all of this time--despite desperate measures with water, etc. means
it's probably unstoppable.

And here we sit--with our own damn EPA discontinuing radiation readings on our milk, water, produce and
rainwater.

[Uben]

2. Oops!

My calculations were off a bit. It'll be May 21,3011 instead of 2011. My bad, didn't carry the one over. But, don't let a mere millenia keep you from being prepared. We still have lots of survival equipment on sale now!

[HubertHeaver]

9. In layman's terms, it means we are cooked.

[azul]

10. It means that secrecy is as dead as a doornail

because now corporations' first responsibility is to the health and safety of living things?

It means that we do not put guns that shoot swords in the hands of young children, as maybe Dylan would say if he hadn't have taken that tumble.

[krispos42]

11. The fuel melted

There was enough chain reactions in the splitting of atoms to release enough heat to melt the fuel into a big puddle.

And of course, this is because the containment system was cracked open after the cooling system failed due to (ironically) flooding from the tsunami.

No cooling and no control over the fuel resulted in an overheat and meltdown. It's open to the air now, and all the radiation and heavy particles spewing from the ongoing reaction are vaporizing metals and irradiating the air. Turning carbon and nitrogen and oxygen into unstable isotopes. And those unstable isotopes will be in our lungs and our food and tissues when they decided to split, releasing a burst of radiation and a heavy particle into our cells.


Fun fun fun.

[The Backlash Cometh]

14. Thank you.

[jeff47]

16. Not remotely close to accurate.

But great fearmongering!

[krispos42]

18. Care to explain?

Or are you just a drive-by poster?


The radiation is traveling downwind. Since this is far less than the speed of light, this must mean it is being carried on something in the air (dust, moisture, particles) or in the air itself.

Otherwise, it would simply fly in a straight line through the cracks in the containment vessel at the speed of light. Like a laser beam, only with x-rays and gamma rays.

[jeff47]

20. Well, first, the radiation is not making oxygen and nitrogen radioactive.

because that's not how fission works, nor is it how one can come up with the radioactive isotopes of carbon, oxygen or nitrogen.

Second, only one type of radiation is in the form of photons, gamma radiation. The radioactive material is releasing a little gamma, but mostly beta radiation. Which is more commonly known as a high-energy electron. So your 'speed of light' thoughts are not relevant.

Third, radioactive material decays over time. When you detect radiation, you are detecting the alpha, beta or gamma particles coming from some radioactive material. Those particles aren't going to float around for thousands of miles to show up over the US. They will hit things, such as the air, and thus dissipate. The radiation comes from actual radioactive material in the air, not radioactive material over in Japan.

The radiation comes from particles of the fuel or it's byproducts that were blasted into the atmosphere during the initial explosions. It's dust, not the gases that make up our atmosphere.

Since there is no fire, and I don't see a way there could be additional explosions, the danger is contamination through the water being used to cool the plant and rain washing the dust off. That's an enormous problem locally. But isn't going to affect us.

[uppityperson]

28. THANK you.

I very much appreciate your taking the time to write this. It is still a huge catastrophe for those around it but calling for fear of radioactive oxygen isotopes is way beyond called for.

[Leopolds Ghost]

33. Good to know you think this is a local problem and doesn't affect us

Merely because "we" aren't the ones being irradiated.

Were people similarly this disinterested in Chernobyl?

Edit: And no, I don't believe inaccurate info provided by other posters about the mechanics of radiation. That's the problem, you're dismissing the real danger as not a concern for us, and arguing over misinfo instead.

[jeff47]

51. So it's wrong to explain that one group is affected more than another? (nt)

[JuniperLea]

36. I'm bookmarking this...

So I know where to deliver the crow.

[krispos42]

37. Ah, a good answer

Thank you.

I knew the speed of light was irrelevant... I said as much in the post. The fact that it is drifting downstream means that SOMETHING that is radioactively decaying is being carried on the air currents.

I mentioned the vaporizing metals in my prior post. And both uranium and plutonium are metals, if memory serves. I would also include in this any of the metals in the reactor vessel (e.g., iron, titanium, chromium, other alloying elements) that got bombarded by fission-related subatomic particles before being vaporized by the heat of the meltdown and evaporated into the air.

I'm glad I'm wrong on the radioactive air, though. I was thinking that the oxygen and nitrogen might become a radioactive isotope from close proximity to the meltdown, and all the sea water they sprayed on it (H₂O with traces of other elements dissolved in it) might have become radioactive from contact before evaporating.

[jeff47]

49. Again, radioactivity does not work that way.

I would also include in this any of the metals in the reactor vessel (e.g., iron, titanium, chromium, other alloying elements) that got bombarded by fission-related subatomic particles before being vaporized by the heat of the meltdown and evaporated into the air.

You can't turn iron, titanium or chromium radioactive by bombarding it with neutrons. There are very, very few elements that become radioactive when bombarded with neutrons or other products of radioactive decay. Virtually all the radioactive elements from incidents like this are the decay products of the uranium fission. That radioactive iodine was once uranium.

In addition, the heat of the meltdown has not vaporized the reactor vessel. You can tell because the reactor vessel still exists. I'd expect the heat to be the greatest at the bottom of the vessel, where the fuel has pooled. Yet the fuel has not melted through the bottom of the vessel yet, which one would think a logical prerequisite to getting sufficient heat to vaporize it. And since we're talking about stainless steel, the temperature necessary to vaporize it is more like millions of degrees, not hundreds.

As for uranium and plutonium being metals, yes the elements are. Nuclear fuel isn't. It's a non-metallic mixture, resembling graphite.

The material that has been mixed into the atmosphere is from the steam and hydrogen explosions. Those have stopped, so more material isn't going into the atmosphere. However, what was in the atmosphere is going to take a while to fall out. And dust that had settled could be stirred up again.

Lastly, "other elements" that are dissolved in water are not carried into the atmosphere when that water evaporates. You can test this at home by mixing up a solution of water and salt, and letting the water evaporate. The salt will remain behind.

[flamingdem]

55. Three of the nukes are spewing white smoke as of this morning nt

[jeff47]

64. Link? (nt)

[flamingdem]

65. Check out Arnie Gundersen's video posted by bananas here today at minute 4 nt

[jeff47]

69. Ah, Arnie. Got a real link?

'cause I can't find anything about it at, say, NHK.

(My issues with Arnie is he overstates his experience, and always leaps to the worst-case scenario when there isn't enough information to actually make a conclusion. If you're gonna lie about what you've done, I'm gonna have to take a careful look at everything you say based on that. And when what you say can't be supported by the data available, I'm gonna have to really start doubting you.)

[flamingdem]

39. You are wrong. All you have to do is look at EPA and UC Berkeley testing nt

[jeff47]

50. Testing what? Presence of radioactivity?

I already said there was radioactive material present. The distinction I'm trying to explain is radioactive material is not radiation. Radiation is the output of radioactive material when it decays. So if you are detecting radiation, you know there is radioactive material.

[flamingdem]

60. Why do you think that is so important?

It's clear it's getting here on dust particles, so why split hairs?

[jeff47]

61. Because the difference is extremely important

If one believes that the radiation is coming directly from the plant, then one would think bad ideas like entombment were good ideas.

[flamingdem]

57. Please checkout Tetuso Matsui's analysis about nuclear chain reactions

Click to add this author to your Ignore list Wed May-11-11 01:49 PM
Original message
Chain Reactions Reignited At Fukushima After Tsunami, Says New Study (MIT)

Edited on Wed May-11-11 01:59 PM by flamingdem
http://www.technologyreview.com/blog/arxiv/26738 /

Radioactive byproducts indicate that nuclear chain reactions must have been burning at the damaged nuclear reactors long after the disaster unfolded

-- Original paper:
Tetsuo Matsui's original paper (9 pages with calculations), the link is this: http://arxiv.org/PS_cache/arxiv/pdf/1105/1105.0242v1.pd...

Nuclear reactors produce radioactive by-products that decay at different rates. One common by-product is iodine-131 which has a half life of about 8 days while another is cesium-137 with a half life of about 30 years.

When a reactor switches off, the iodine decays more quickly so the ratio between these two isotopes changes rapidly over a period of days. That's why measuring this ratio is a good way to work out when the nuclear reactions terminated.

There are some complicating factors, however. The most important of these is that the ratio of iodine-131 and cesium-137 to start with depends on how long the reactor has been operating and so is not constant.
That's because, after a reactor has been switched on, the levels of iodine-131 reach an equilibrium on a timescale similar to its half life of about 8 days.

But cesium-137, with a half life of 30 years, takes much longer to reach equilibrium. To all intents and purposes, the levels of cesium-137 in a reactor continue to grow steadily during the timescales over which reactors are usually operated. MORE AT LINK

[jeff47]

62. And as I keep saying, that doesn't really change what you do with the plant

Keep pumping water with boron in it, cool the fuel to the point where you can remove it.

[NNN0LHI]

12. I highly recommend reading this

http://www.science20.com/nonpragmatic_engineer/introduction_radiation-77286

[truebrit71]

15. Thanks I asked the same question in another thread...

...hopefully we can get a concise answer because at this point I don't know what we're talking about..

[jeff47]

19. What we're talking about is this:

Uranium can only go through fission if there are enough neutrons bouncing around. The control rods stop the neutrons. When the earthquake hit, they put the control rods all the way in to stop the uranium fission. That was successful.

However, uranium splits into atoms that are unstable. And those atoms will go through fission no matter what. Fission of those atoms produces heat, which is why even the "spent" fuel has to be cooled for years.

The tsunami caused the cooling to fail. So the fuel got really, really hot, and melted into a pile of slag that is currently resting at the bottom of the reactor. Since the fuel melted, it is currently unclear if uranium fission was able to restart. The fuel isn't where it's supposed to be, so the control rods aren't going to be as effective. At the same time, the pile of slag isn't an efficient reactor, so there might not have been enough neutrons to restart uranium fission. From our distant observer perspective, it doesn't really change anything.

Anyway, the reactors are currently being cooled, and as long as that continues the fuel won't melt any further. Leaks and cracks in the cooling system are a concern for local contamination, but they've got enough pumping capacity to keep the fuel cool even with the leaks.

The "doomsday" scenario is the cooling completely fails again, the fuel gets hot again, and it melts through the bottom of the reactor. In that scenario, the fuel will flow kinda like toothpaste into the concrete pits below the reactors. Once there, the fuel spreads out over a large surface area, helping to cool it. These pits are also currently flooded with water to provide lots of additional cooling in case this does happen. This leaking out the bottom of the reactor is the basis of for "China Syndrome". However, the fuel can't actually melt very far through the Earth. And even if it could, gravity doesn't work like that.

There is massive danger of contamination locally. Work in and around the reactors would be _extremely_ dangerous and difficult. However, the material isn't going to suddenly leap into the air and fly around the world. Something would have to propel the material into the air in order for contamination to spread more broadly. In Chernobyl's case, the fire did that. But these reactors don't use the same flammable design. Earlier in this incident, the steam and hydrogen explosions propelled material into the atmosphere. In the current situation, I'm having trouble coming up with a scenario where there could be a fire, explosion or gas pressure build-up where radioactive material is thrown into the air - one of the 'benefits' of all the leaks is you won't get a build-up in pressure.

Short simple terms answer: It really sucks for people who live there. It may really suck for other parts of Japan. We're still fine.

[NNN0LHI]

21. Does the neutron beam observed 13 times, 1.5 kilometers from the plant indicate criticality?

http://www.japantoday.com/category/technology/view/neutron-beam-observed-13-times-at-crippled-fukushima-nuke-plant

Neutron beam observed 13 times at crippled Fukushima nuke plant

Thursday 24th March, 06:31 AM JST

TOKYO — Tokyo Electric Power Co said Wednesday it has observed a neutron beam, a kind of radioactive ray, 13 times on the premises of the Fukushima Daiichi nuclear plant after it was crippled by the massive March 11 quake-tsunami disaster.

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant’s No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level.

[jeff47]

22. It's the evidence for uranium fission occuring

However, there are other people claiming those reports are erroneous.

It's something that the people working at the plant should be concerned about. However, it doesn't change what should be done: cool the fuel until it can be removed from the reactor. Uranium fission hinders that, as it creates new sources of heat, but what you do about it is just keep pumping.

[NNN0LHI]

23. Keep pumping for how long?

I can wrap my mind around cooling long thin rods by constantly circulating water around them.

But I have a hard time doing the same with the notion of trying to cool a huge glob of this material shaped like a basketball.

Am I correct on this?

And who was reporting that the neutron beams that Tepco reported seeing were erroneous if you don't mind me asking?

Don

[jeff47]

25. Admittedly I oversimplified the pumping operation

What you do is add boron to the water you're pumping into the reactor. The boron absorbs the neutrons and stops the uranium fission much like the control rods.

And the fuel isn't a basketball. It's spread over the bottom of the containment vessel. So we're talking something with a rounded bottom side and a flat top side. There's enough surface area there to cool it and for the boron to prevent criticality. At least, as far as we can see from this far away.

As for the doubts about the neutron beams, I don't have a source handy. I do remember there being a controversy when it was first reported. But with or without the beams, the boron-laced water pumped through the reactors is what you do.

[flamingdem]

40. Yes, and much worse because there is a leak, so they have to fill fill and dump nuked waste nt

[robdogbucky]

24. Nice try, but your explanations don't wash

Vessels cracked: check
Cold Shutdown impossible: check
Release of radiation continues unabated into ground, into ocean, into air: Check
Water poured into reactors is leaking out, no solution: Check
These reactors cannot be entombed ala Chernobyl: Check
We will continue to experience radiation leaks that will migrate radiation to the US West Coast: Check

Thanks for playing


Local extreme enviroweenie biased claptrap spewing radical here, signing off for now. (that is what DUer called me on March 11)


rdb

[jeff47]

27. So....the laws of physics don't exist.

Good to know. I've been wanting my own FTL spaceship for a while now.

[Leopolds Ghost]

41. Do you feel this is worse or much less serious than Chernobyl?

Inquiring minds and all that.

[jeff47]

47. Much, much less

In the Chernobyl incident, the raging inferno was pumping fuel into the atmosphere. Think of it as radioactive soot. That fuel then fell out over a large area.

In this case, there has been some material thrown into the atmosphere from the initial steam and hydrogen explosions. But much less material.

It is indeed very, very bad for the area around the plant. But unlike Chernobyl it's not a significant danger to those thousands of miles away.

Now, they're going to be of equal rating on that 7-point scale. But that's more a limitation of the scale than the nature of the two events.

[flamingdem]

58. This thread is about a Japanese scientist who has evidence chain reaction has been occurring

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=293568&mesg_id=293568

[wiggs]

31. Is radioactive iodine an issue here? I realize it may not be the same order of

magnitude as Japan has and it's not the same concern as a possible explosion with all kinds of particles with longer half-lives entering the atmosphere...but is it prudent to avoid milk so that a very VERY low risk of cancer doesn't increase to merely a very low risk of cancer from iodine?

I've had my girls (living in SF) switch to soy milk for a month now, not trusting official statements to get out ahead of any potential problem.

[jeff47]

48. I really can't answer that for you

in that I can't know what level of risk you are willing to tolerate. The change in risk is not 0. At the same time, the change in risk is extremely small.

If I was in your situation, I'd still be giving my kid regular milk. She'd be in far more danger riding in my car than from "big milk" and the government hiding radioactive milk. But I'm on the east coast, and my kid isn't born yet. You'll have to do what you feel comfortable with.

[Edweird]

53. IIRC, there aren't any 'concrete pite under the reactors'. It's going to hit ground water.

[flamingdem]

59. Where did you read that? I've been trying to find that info thanks nt

[flamingdem]

56. Are you sure there is a concrete pit under each reactor?

There was talk about attempting to put concrete under no. 1 a while ago, so I'm not so sure.

[jeff47]

63. The only addition of concrete I'm aware of is to repair the concrete under reactor #3.

My understanding is these use the "standard" design for Mk1 reactors, which includes the concrete pit as a safety measure.

[BOG PERSON]

17. each of us will have a cool superpower very soon

either that or the rest of our lives are going to be one long agonizing slow-roast.

[jtuck004]

26. Drumbeat of Nuclear Fallout Fear Doesn't Resound Wtih Experts

Story, here

The fear is unwarranted, experts say. People in Japan near the Fukushima Daiichi nuclear power plant may have reason to worry about the consequences of radiation leaks, scientists say, and some reactor workers, in particular, may suffer illness. But outside of Japan, the increase is tiny, compared with numerous other sources of radiation, past and present.

...

That perspective suggests a human population and a global environment in which exposure to radiation is constant and significant. For example, people around the globe were exposed to radioactive fallout from hundreds of nuclear bomb test explosions in the atmosphere during the cold war. Today, medical patients choose to be exposed to regular doses of radiation from millions of X-rays and CT scans.

...

“It disappears as a contributor to population radiation doses,” said Frank N. von Hippel, a nuclear physicist who advised the Clinton administration and now teaches at Princeton University. But the fear of radiation is different. “Somehow,” Dr. von Hippel added, “nuclear things get stigmatized relative to their statistical risks.”

...
Additionally, many experts say, the threat to the Japanese people is probably low because — unlike the radioactive fallout from the cold war and the Chernobyl accident — most of the radiation is believed to have blown out to sea on the prevailing winds.
...


It is still ongoing, and, frankly, it is tough to glean reliable information from the storm of true believers on both sides. So I try to read as much as I can of both, and stay in touch with others who can tell me what it is really like there. Personally I think it is a little more dangerous than is being officially acknowledged, and not nearly as much as the hysterical would have you believe.

[uppityperson]

29. Thank you also. For those near Fukushima, it is terrible.

I also feel the truth is somewhere between the official acknowledgement and "oxygen is radioactive" calls.

[JuniperLea]

34. Nuclear industry PR...

The amount of radiation noted in these "usual" ways we come into contact is spread over years... we're talking about having a life's worth of chest, dental, and other xrays, plus all the air travel a human can possibly have, plus a dozen or so CT scans and some cancer radiation therapy all rolled into a short span... and that's for those of us who are lucky enough to live in California, not Japan.

There are reasons radioactivity is "stigmatized." Very valid reasons even.

It will be difficult to save this industry. What we are seeing now are the begining of a long white washing.

[Leopolds Ghost]

35. So this disaster is officially nowhere near as bad as Chernobyl?

[progressoid]

30. ...

[Leopolds Ghost]

38. Even worse...

[Keith Bee]

32. Ug! God ANGRY!

Punish! :nuke:

[defendandprotect]

42. k

[Hannah Bell]

43. it means a lot of people are posting misleading articles from the western press

and a lot of people reading them haven't been following the story.

http://www3.nhk.or.jp/daily/english/12_23.html

[NNN0LHI]

44. I read Japans state run media arm(NHK) every day first thing

Got it in my favorites.

Don

[Hannah Bell]

45. then you must have noticed the differences between the nhk story of the 12th

and the telegraph & abc stories reporting the same story.

[NNN0LHI]

46. I expected differences

Didn't you?

Don

[jpak]

67. It means the pollyannas were wrong and the accident is NOT over and large amounts of radioactivity

has been released into the environment

yup

[Odin2005]

52. I believe it is the classic meltdown scenario, like Chernobyl.

That what it sounds like to me, at least.

Thank God this can't happen in the newer nuclear plant designs, the old ones need to be phased out.

[flamingdem]

54. This one at least has a containment structure

but that appears to have been broken through by the corium.

Where it stops.. nobody knows.

[jpak]

66. It means that everything is OK and we can build more nukes

or so we will be told

[WinkyDink]

68. It means the truth will come out with the births from the second generation hence.