Posted by
Roblimo
on from the sometimes-you-get-burned-when-you-play-with-fire dept.
Cy Guy writes "I'm sure there will be many more stories on this soon, for now, here is the wire story." An update sent in by cheetah: "It appears that someone mixed about 6 times too much uranium into a fuel processing tank. For the latest info click Here"
At the moment the best information that I have could (charitably) be called 'hearsay and rumour', but here's how I understand it so far:
1) This was a fuel processing facility, so comments like 'meltdown', 'China syndrome' and 'Chernobyl' are ridiculous.
2) It is reported that approx. 5 times the correct amount of Uranium was introduced into a chemical treatment vessel.
3) Two plant workers are 'seriously ill'. 30+ others were 'exposed'
4) Totally unconfirmed reports have been published of workers 'seeing a blue light' and feeling unwell.
5) People have been advised to stay indoors and wash off any rainwater they may have been in contact with.
Point 1: This facility is *not* a nuclear reactor. The worst that is likely to happen is a nasty, rather radioactive, chemical mess that will take a lot of time and effort to clean up. Even if the nuclear reaction (that may or may not have taken place) is still continuing, it will cool down on it's own. It is very difficult to design a reactor to keep a fissile reaction running for any length of time.
Point 2: It will be some time before we know why too much uranium was allowed into the processing environment. Let's not start blaming anyone until we know the facts.
Point 3: If you are listed as 'seriously ill' after an being involved with an event like this then you will be extremely lucky to live. My thoughts are with these people and their families.
Point 4: I don't know whether to believe this. The blue light sounds like Cerenkov radiation. If you start feeling ill just after seeing this, then you are certainly in the 'seriously ill' category. I doubt you'd be talking to reporters. It may have happened, but I'll wait for more information. You need a *lot* of nuclear activity for Cerenkov radiation to be obvious.
Point 5: Very sensible advice. If it was raining at or soon after the time of the accident, then the rain will absorb a lot of the 'nasties' from the air and wash them to the ground. In these conditions staying inside, closing the windows and avoiding contact with radioactive rain seems to be a good idea. Would you rather get in a car, sit in a traffic jam and wonder how much rain is in the car's ventilation systems? The instinct is to get as far away as possible, but a house is probably safer than a car.
We need to make sure that the Japanese authorities are given every possible assistance in dealing with this. Then we need to find out how it happened. Then we need to put measures in place to stop it from happening again. It has happened before on several occasions, at least once in US, once in UK and once in what was USSR.
Before you get all excited
by
konstant
·
· Score: 4
I have a feeling some of the more extreme technophiles/conservatives are going to chastise us for being alarmed by this sort of accident. Generally, after a nuclear mishap, the pattern goes like this:
1) BOOOM 2) a number of people are rushed to the hospital 3) liberals run around screaming "Look how awful nukes are!" 4) conservatives tilt their Laz-e-boys up a notch, puff on their pipes, and make devastating comments about "Luddites"
But look folks, nuclear technology really is a technology unlike most others. Only genetic modification has as much potential for literally wiping out the human race if somebody forgets to carry the two. We all know from experience that even experts make miscalculations, and that sometimes the results are hazardous. Generally, these are tragic but containable. They are what you might call "acceptable losses" on the path towards improving the lot of our species.
But I'll be damned if waking up each morning to a pitcher of radioactive milk is acceptable to me. Just a single reactor in Russia threw the world's food supply into havoc for months. And mistakes like Chernobyl have happened before and will happen again. Every once in a while somebody fucks up. It's just that, with nukes, the ramifications are so very large!
The reason that we don't see more accidents like this in Japan is not because nuclear energy is, on the whole, safe. It's because most people have extreme NIMBY reactions to nuclear facility proposals. People are scared of nuclear technology, and I think rationally so. The development of a clever scientific pet trick is not enough justification for its deployment. We do not have to do everything that we can do.
I'm sure that statement alone will be enough to moderate me down on slashdot;)
-konstant
-- -konstant Yes! We are all individuals! I'm not!
Here's a brief description of the primary types of radiation and their relative harmfulness.
1) Alpha radiation. Alpha particles are helium nuclei, big and slow; they can be stopped by a sheet of paper, but if you inhale alpha emitters, they can tear up your lung cells. So don't do that.
2) Beta radiation. Beta particles are energetic electrons, and can penetrate a bit better than alpha particles, but you should be okay if you're in the next room.
3) Gamma radiation. Gamma rays are *very* energetic photons; these are the ones that'll get ya. You need a good amount of dense shielding to absorb these.
4) Neutrons. Energetic neutrons from radioactive decay both perpetuate the chain reaction, and cause direct damage like beta particles, only worse because they're heavier.
The people close to this one will probably have gotten a good zap of gamma radiation, and will be in a world of hurt. But unless radioactive *material* (such as the uranium itself) escapes into the surrounding air, nearby civilians should be okay unless there is inadequate shielding against gamma rays.
In a nutshell, this is Really Bad, especially for the people closest, but the Earth is not about to collapse into a molten ball...
Criticality in solutions of heavy isotopes
by
Anonymous Coward
·
· Score: 5
...is easier to achive than you think.
(Snarl, network here is on the fritz, apologies if this comes through multiple times - connection reset by peer before anything actually gets submitted, I'm assuming...)
Anyone working at a nuke plant, especially a fuel processing plant, knows this. This incident appears to have been caused by stupidity of truly mind-boggling proportions.
If you're ever working with heavy isotopes (i.e. fissionables) in solution, the water or other solvent in which the compounds are dissolved can act as a moderator, and the amount of uranium or other fissionable matter required for criticality drops precipitously.
I did a few summer terms at a research reactor at a university. This reactor was often used to create compounds for medical use as well as other research. Preventing this type of incident was discussed in one of the most heavily-underlined-and-boldfaced sections of text in the book.
Any time you have to work with heavy unstable isotopes in solution, it's imperative that you know exactly what you're dealing with. That means you need to know both the nuclear (cross-sectional) and the chemical properties of both solvent and solute, AND the shape of the container, AND the concentrations expected at any stage in the dissolution.
Those latter two are particularly counterintuitive - but are glaringly obvious in hindsight, as they're significant factors in the mean distance (i.e. free path) between particles of the heavy isotope in the solution, a key determinant in criticality.
To give an example of what can go wrong - take a beaker of water and drop in a spoonful of brown sugar. Pretend the sugar is fissionable.
At the start, you have a subcritical mass of brown sugar. Safe enough to hold in your hand. At the end, the sugar is distributed evenly enough through the water that even with the water's moderating effect, it's subcritical. Safe enough to work with.
Walk away from the beaker and come back in 5 minutes. Observe that there are regions in the beaker of varying concentrations. At least one of these concentrations will be the "right" concentration to minimize the mass required for criticality. If the volume of that region is large enough, it goes critical in that region and it's game over.
For an even better version of this game, imagine you can stir it quickly enough so that this is never a risk. Mix it in a baking pan, so that the liquid is never deeper than 1cm, and most of the neutrons fly out the top and bottom of the pan. Give it to your friend, who pours it into one of those nice flasks with the spherical bottoms. The spherical shape allows many more neutrons to be absorbed. Your last thought is that "Safe enough to work with" only means "safe enough to work with in this container". Game over.
Or just carelessly leave the pan under the fume hood over the weekend. Or toss it in the freezer, and discover that as it freezes, the capacity to hold the material in solution changes, and some of it precipitates out. In either case, don't expect to get any work done on Monday morning, though.
Of course, now that I've gone through the hard ways to have this accident (about which anyone working in this environment would still know), putting seven times as much solute in the solution would also be a good way to screw it up.
Scary thought: If they could see the Cerenkov radiation - and weren't looking at the tank - it means the radiation flux through the fluid in the eyeball was high enough to cause a visible blue glow. That's a lot of radiation.
Remember all those "how to build your own atomic bomb" plans, that all worked out to "this won't give you a nuclear detonation, but it'll make one unholy hell of mess"?
The Japanese have just become the test case. While we're not talking about levelling cities or nuclear explosive yield, in terms of the physics involved - an uncontrolled chain reaction in a critical mass - the Japanese have arguably just nuked themselves, in the same sense that the Americans nuked them twice earlier this century.
It's a banner week for Darwinian Stupidity in the sciences, folks. First we lose a $125M space probe because two engineering teams didn't know the difference between metric and Imperial measure, and then a couple of Japanese fuel processing guys manage to top our blunder by accidentally building and activating something that's the fundamental equivalent to the core of an atomic bomb.
Slashdot Mirror
At the moment the best information that I have could (charitably) be called 'hearsay and rumour', but here's how I understand it so far:
1) This was a fuel processing facility, so comments like 'meltdown', 'China syndrome' and 'Chernobyl' are ridiculous.
2) It is reported that approx. 5 times the correct amount of Uranium was introduced into a chemical treatment vessel.
3) Two plant workers are 'seriously ill'. 30+ others were 'exposed'
4) Totally unconfirmed reports have been published of workers 'seeing a blue light' and feeling unwell.
5) People have been advised to stay indoors and wash off any rainwater they may have been in contact with.
Point 1: This facility is *not* a nuclear reactor. The worst that is likely to happen is a nasty, rather radioactive, chemical mess that will take a lot of time and effort to clean up. Even if the nuclear reaction (that may or may not have taken place) is still continuing, it will cool down on it's own. It is very difficult to design a reactor to keep a fissile reaction running for any length of time.
Point 2: It will be some time before we know why too much uranium was allowed into the processing environment. Let's not start blaming anyone until we know the facts.
Point 3: If you are listed as 'seriously ill' after an being involved with an event like this then you will be extremely lucky to live. My thoughts are with these people and their families.
Point 4: I don't know whether to believe this. The blue light sounds like Cerenkov radiation. If you start feeling ill just after seeing this, then you are certainly in the 'seriously ill' category. I doubt you'd be talking to reporters. It may have happened, but I'll wait for more information. You need a *lot* of nuclear activity for Cerenkov radiation to be obvious.
Point 5: Very sensible advice. If it was raining at or soon after the time of the accident, then the rain will absorb a lot of the 'nasties' from the air and wash them to the ground. In these conditions staying inside, closing the windows and avoiding contact with radioactive rain seems to be a good idea. Would you rather get in a car, sit in a traffic jam and wonder how much rain is in the car's ventilation systems? The instinct is to get as far away as possible, but a house is probably safer than a car.
We need to make sure that the Japanese authorities are given every possible assistance in dealing with this. Then we need to find out how it happened. Then we need to put measures in place to stop it from happening again. It has happened before on several occasions, at least once in US, once in UK and once in what was USSR.
I have a feeling some of the more extreme technophiles/conservatives are going to chastise us for being alarmed by this sort of accident. Generally, after a nuclear mishap, the pattern goes like this:
;)
1) BOOOM
2) a number of people are rushed to the hospital
3) liberals run around screaming "Look how awful nukes are!"
4) conservatives tilt their Laz-e-boys up a notch, puff on their pipes, and make devastating comments about "Luddites"
But look folks, nuclear technology really is a technology unlike most others. Only genetic modification has as much potential for literally wiping out the human race if somebody forgets to carry the two. We all know from experience that even experts make miscalculations, and that sometimes the results are hazardous. Generally, these are tragic but containable. They are what you might call "acceptable losses" on the path towards improving the lot of our species.
But I'll be damned if waking up each morning to a pitcher of radioactive milk is acceptable to me. Just a single reactor in Russia threw the world's food supply into havoc for months. And mistakes like Chernobyl have happened before and will happen again. Every once in a while somebody fucks up. It's just that, with nukes, the ramifications are so very large!
The reason that we don't see more accidents like this in Japan is not because nuclear energy is, on the whole, safe. It's because most people have extreme NIMBY reactions to nuclear facility proposals. People are scared of nuclear technology, and I think rationally so. The development of a clever scientific pet trick is not enough justification for its deployment. We do not have to do everything that we can do.
I'm sure that statement alone will be enough to moderate me down on slashdot
-konstant
-konstant
Yes! We are all individuals! I'm not!
Here's a brief description of the primary types of radiation and their relative harmfulness.
1) Alpha radiation. Alpha particles are helium nuclei, big and slow; they can be stopped by a sheet of paper, but if you inhale alpha emitters, they can tear up your lung cells. So don't do that.
2) Beta radiation. Beta particles are energetic electrons, and can penetrate a bit better than alpha particles, but you should be okay if you're in the next room.
3) Gamma radiation. Gamma rays are *very* energetic photons; these are the ones that'll get ya. You need a good amount of dense shielding to absorb these.
4) Neutrons. Energetic neutrons from radioactive decay both perpetuate the chain reaction, and cause direct damage like beta particles, only worse because they're heavier.
The people close to this one will probably have gotten a good zap of gamma radiation, and will be in a world of hurt. But unless radioactive *material* (such as the uranium itself) escapes into the surrounding air, nearby civilians should be okay unless there is inadequate shielding against gamma rays.
In a nutshell, this is Really Bad, especially for the people closest, but the Earth is not about to collapse into a molten ball...
(Snarl, network here is on the fritz, apologies if this comes through multiple times - connection reset by peer before anything actually gets submitted, I'm assuming...)
Anyone working at a nuke plant, especially a fuel processing plant, knows this. This incident appears to have been caused by stupidity of truly mind-boggling proportions.
If you're ever working with heavy isotopes (i.e. fissionables) in solution, the water or other solvent in which the compounds are dissolved can act as a moderator, and the amount of uranium or other fissionable matter required for criticality drops precipitously.
I did a few summer terms at a research reactor at a university. This reactor was often used to create compounds for medical use as well as other research. Preventing this type of incident was discussed in one of the most heavily-underlined-and-boldfaced sections of text in the book.
Any time you have to work with heavy unstable isotopes in solution, it's imperative that you know exactly what you're dealing with. That means you need to know both the nuclear (cross-sectional) and the chemical properties of both solvent and solute, AND the shape of the container, AND the concentrations expected at any stage in the dissolution.
Those latter two are particularly counterintuitive - but are glaringly obvious in hindsight, as they're significant factors in the mean distance (i.e. free path) between particles of the heavy isotope in the solution, a key determinant in criticality.
To give an example of what can go wrong - take a beaker of water and drop in a spoonful of brown sugar. Pretend the sugar is fissionable.
At the start, you have a subcritical mass of brown sugar. Safe enough to hold in your hand. At the end, the sugar is distributed evenly enough through the water that even with the water's moderating effect, it's subcritical. Safe enough to work with.
Walk away from the beaker and come back in 5 minutes. Observe that there are regions in the beaker of varying concentrations. At least one of these concentrations will be the "right" concentration to minimize the mass required for criticality. If the volume of that region is large enough, it goes critical in that region and it's game over.
For an even better version of this game, imagine you can stir it quickly enough so that this is never a risk. Mix it in a baking pan, so that the liquid is never deeper than 1cm, and most of the neutrons fly out the top and bottom of the pan. Give it to your friend, who pours it into one of those nice flasks with the spherical bottoms. The spherical shape allows many more neutrons to be absorbed. Your last thought is that "Safe enough to work with" only means "safe enough to work with in this container". Game over.
Or just carelessly leave the pan under the fume hood over the weekend. Or toss it in the freezer, and discover that as it freezes, the capacity to hold the material in solution changes, and some of it precipitates out. In either case, don't expect to get any work done on Monday morning, though.
Of course, now that I've gone through the hard ways to have this accident (about which anyone working in this environment would still know), putting seven times as much solute in the solution would also be a good way to screw it up.
Scary thought: If they could see the Cerenkov radiation - and weren't looking at the tank - it means the radiation flux through the fluid in the eyeball was high enough to cause a visible blue glow. That's a lot of radiation.
Remember all those "how to build your own atomic bomb" plans, that all worked out to "this won't give you a nuclear detonation, but it'll make one unholy hell of mess"?
The Japanese have just become the test case. While we're not talking about levelling cities or nuclear explosive yield, in terms of the physics involved - an uncontrolled chain reaction in a critical mass - the Japanese have arguably just nuked themselves, in the same sense that the Americans nuked them twice earlier this century.
It's a banner week for Darwinian Stupidity in the sciences, folks. First we lose a $125M space probe because two engineering teams didn't know the difference between metric and Imperial measure, and then a couple of Japanese fuel processing guys manage to top our blunder by accidentally building and activating something that's the fundamental equivalent to the core of an atomic bomb.