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Interview With Chernobyl Engineer
An anonymous reader writes "New Scientist has posted an interview with a former Chernobyl engineer, Alexander Yuvchenko, who was not only there the night of the explosion, but is still alive today to tell about it. A fascinating recollection of some pretty heroic acts."
For Engineers the treatment was prompt, for the inhabbitants they pulled an "EPA in NYC after 9/11." They didn't evacuate the area, and assured people that all was well. After a week THEN they evacutaed everyone. I don't think the locals received the same top notch treatment.
I boycott signatures
What the hell is wrong with you? He's absolutely right; I was up by columbia (116th) then and a few days after, and even there you could smell the dust. When we visited near the site it was absolutely lung-clogging. I was incredibly thankful that I didn't have to live or work there.
Read jack phelps dot net
That's cuz it was later shown to all be a hoax.
o gs_cher.html
http://www.boingboing.net/2004/05/26/girl_photobl
Google is your friend.
Senior NCO in the fight against entropy. I've seen things, man. Things no one should have to see.....
No, that's not correct. For example, over 3,000 people died in one week in 1952. The problem is the makeup of most coal. From this link
Coal is one of the most impure of fuels. Its impurities range from trace quantities of many metals, including uranium and thorium, to much larger quantities of aluminum and iron to still larger quantities of impurities such as sulfur. Products of coal combustion include the oxides of carbon, nitrogen, and sulfur; carcinogenic and mutagenic substances; and recoverable minerals of commercial value, including nuclear fuels naturally occurring in coal.
MORE NUCLEAR MATERIALS ARE RELEASED BY COAL BURNING THAN ANY NUCLEAR PLANT HAS EVER RELEASED. That's a VERY important thing to know, because COAL KILLS PEOPLE.
Javascript + Nintendo DSi = DSiCade
the sad part is, some of them are still running ...
The following is the Paper everyone will link to. And the following provides some nice diagrams to look at
And just for kicks: Some really freaky pictures. (The second one really gets to people, he is working IN the bloody thing!!)
Sunny Dubey
>The disaster was caused partly by one engineer previously over-riding automatic safety protection in order to increase reactor power to levels needed to run a safety test.
Uh, IIRC the reason the thing blew is that the power levels were decreased to too low a level to sustain stable reaction.
I'm not a nuclear physicist, but I believe in that style of reactor, the presence of the particular water they were using decreased the reaction speed, instead of increasing it as it is done in modern, western reactors. So they had the control rods pulled all the way out, and the water flow super low.
Then the water started to boil a little, and that boiling caused bubbles in the moderating water, which allowed the reaction speed to launch into some nasty exponential power spike that could not have been prevented in the time it took to see the spike.
I'm pretty sure what I just wrote was mostly right. I'm just too lazy to find links. But I am sure that the power level was super super low, and the control rods were pulled all the way out. Bad idea.
Muerte
I believe that's correct. The greater mass of Alpha particles causes them to be more easily deflected than beta particles. Gamma radiation has a near-zero mass, so it can penetrate most forms of matter. (Penetration being the act of "missing" most of the matter.)
No, the greater mass of alpha particles (2 protons and 2 neutrons, basically a Helium nucleus) makes them more difficult to deflect, not less. However, other factors have an impact on the scattering cross section, including particle charge and energy.
Gamma particles have a zero rest mass, since they are simply energetic photons.
I think you may be getting confused by Neutron radiation, which is the most massive type of radiative particle. Neutrons do a LOT of damage due to their mass, but they don't actually have a lot of penetrating power.
No, Neutrons are less massive than alpha particles.
Tubal-Cain smokes the white owl.
For those not versed in things nuclear (and why positive temperature coefficient of reactivity reactors are a BAD IDEA), a good background on the accident and nuclear power in general.
-- Fugacity: Confusing chemists since 1908
...as those in the UK might realise, the newspaper The Guardian also published today a much longer and more detailed article with Sasha Yuvchenko, another engineer working at Chernobyl at the time who survived the disaster. He too comments on the excellent medical care he recieved. Read it here.
"It reminds me of a story of the F-16 pilot sitting on the ground who thought the aircraft would stop him raising the gear when on the ground. So he tried it and discovered that yes he could indeed raise the gear contrary to his expectation, now I ask you why would to do something so dumb?"
Most likly a myth. Every airplane with retactable gear I know of have what they call squat switches that prevent the gear from retracting when the plane is on the ground. Also the way the gear on the F16 retracts I doubt that it could retract with the plane sitting on it.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
Life expectancy in Britain (m/f) (yr 2000): 75.7/80.4
;)
Life expectancy in the US (m/f) (yr 2000): 74.1/79.4
Combined total healthcare costs per capita, Britain (yr 1998): 4,178$
Combined total healthcare costs per capita, USA (yr 1998): 1,461$
I'll take the British system, thanks (and several dozen others) over the US system. If I have to fork over some extra to take care of my teeth, it's no big deal
No matter how kind you are, German children are kinder.
No, beta particles are deflected more in a magnetic field than alpha particles are, all things being equal.
Alpha particles are essentially helium nuclei, they have a charge of +1 and a mass of 4. Beta particles are electrons, they have a charge of -1 and a negligible mass when compared to an alpha particle (each proton is about the mass of 1800 electrons). Gamma particles are high-energy photons with no charge and essentially no mass at all.
When they are ejected in the same direction with the same velocity through a uniform magnetic field it is the beta particle which will be deflected more. This is due to the fact that both particles will have the same force acting upon them, but they have a different mass. Since the alpha particle has much more mass it will be deflected a lot less by the force and so it will curve less than the beta particle. The gamma radiation will not curve at all because photons have no charge and will hardly be affected by a magnetic field.
As for deflection, the alpha particles take up a lot of room. When they encounter other material they are much more likely to have a collision than beta particles which have a very small volume. This means that the alpha particles usually only travel a small distance through a material before slowing down enough to be stopped. Beta particles get slowed down less because they tend to be able to slip right past the atoms (actually past the nuclei) in the material. Gamma particles penetrate the furthest because they really are only captured occasionally by atoms and quite a large percentage will manage to get through even a couple of feet of low-density material.
Sapere aude!
For those of you who make fun of the Soviet system wen you probably wheren't even born then, this is a lesson: Soviets took care of their people well and their medicine was top.
Eight months ago, I pulled my adopted son out of a Russian hospital in Novosibirsk against the will of the doctor. He had severe asthma and bronchitis which he had contracted while there for minor outpatient surgery. He hadn't been bathed or had his clothes changed in weeks. He was lying in a wet cloth diaper. His crib was made from knit kite string. This is the same hospital where I saw, with my own eyes, supplies being delivered by horse-drawn cart. He is covered in scars. He had more scars at 1 year old than I had at 33. One of them is a scar on his scrotum where they split it front to back for exploratory surgery. In the US, they would have ordered a cat scan. This was last winter. Would you say things have improved since soviet times?
Disconnect your television. Do your own research. Draw your own conclusions. They're probably lying. Don't be a sheep.
More than anything, the Chernobyl disaster reminds me of a Windows user who disables the firewall and antivirus just to install that nifty Explorer toolbar. The difference being that an average Windows user doesn't kill thousands of people through his stupidity...
The main problem seems to be the Radon gas, which as radioactive gas can not be filtered out. Radiation levels near coal plants are higher than near atomic plants.
0 3.htmle ments/Rn -en.htm
9 7/FS-163-97.html looks good.
Some links:
http://www.stormingmedia.us/76/7636/A7636
http://www.lenntech.com/Periodic-chart-el
Especially http://greenwood.cr.usgs.gov/energy/factshts/163-
Moritz
I got my copy several years ago when I was researching the politics of obedience and whether engineer subordinates should be responsible to authority or the laws of physics for a course in Ethics.
The book, "The Truth about Chernobyl", by Grigori Medvedev (ISBN 0-465-08775-2) ( English translation - by the way very well done ) Copyright 1991 by Basic Books, Inc.
( Incidentally, from my research in Ethics, I just about got the feeling that if you were gonna toe the line on Ethics, you had better work for yourself.).
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
Slashdot is proof that Sturgeon's Law applies to mankind.
Fissioning U-235 releases about 200 MeV/fission, or about (2e8 eV/fission)(1.6e-19 J/eV)(6.02e23 fissions/235 g)(0.075 g) = 6e9 Joules per tonne of the more enriched coal. That's about 1.6 megawatt-hours of heat, that can be derived from fissioning the U-235 in a tonne of coal.
Bituminous coal has an energy density of combustion of about 25e9 Joules per tonne, or about 7 megawatt-hours of heat from burning a tonne of coal.
At first glance, the combustion seems to win, especially when you consider that you can only get about 10% of the energy out of the uranium without reprocessing. But if you use the U-238 too (to make plutonium, which will then also fission in a conventional reactor), you get about 100x as much energy as from fissioning just the U-235. Of course, that takes reprocessing the fuel at least once, which is energy intensive, and there will of course be losses in the system. So maybe you only win by 30x. The fission should yield about 50 megawatt-hours of heat in a proper breeder-reactor setup. That's more than ten times the heat of combustion. Even "crappy" coal with only 1.5ppm of uranium in it could match the energy of combustion.
Wow.
Whoops, I labelled those wrong.
The British system was the cheap one. That's what I get for not previewing....
No matter how kind you are, German children are kinder.
Xe-135 is destroyed when it absorbs a neutron. So in an operating reactor is it "burned" rapidly as it is produced. But when you shut off the reaction, Xe-135 levels rise over the next eight hours to a peak level and then decay. This makes it very difficult to start a power reactor eight hours after you shut it down: the Xe-135 acts like an additional control rod, damping the reaction. You find that you have to pull the control rods much farther out to get the reaction started.
There's a problem with that: as soon as you get the reaction going in the core, the Xe-135 will rapidly "burn" off, restoring the usual control laws. That is dynamically unstable, as more neutrons -> less Xe-135 -> more reactive core -> even more neutrons!
The operators should have known what was happening when the found they had to pull the rods much farther than expected in order to bring the reactor stable "zero"-power operation ("zero-power" operation means that a chain reaction is being sustained but is not producing a significant amount of power. It is an important first step in operating the reactor: you start the reaction going, demonstrate positive control, calibrate your control settings, and then proceed to the power level you want. In the reactor where I worked, 5 watts of power, out of a rated maximum of 250 kilowatts, was considered "zero power".).
That unstable positive coefficient (as the Xe-135 burned off) made the reactor spike rapidly in power to a high thermal level -- where the reactor's positive void coefficient [what the Muerte23 described in the parent article] took over. That is a poor element of reactor design -- the Chernobyl reactors were "over-moderated". Fission neutrons come out fast, but uranium absorbs neutrons best when they're moving slowly. So you put the reactive material in a medium (water or graphite or Zirconium hydride or whatever) that will absorb energy from the neutrons without absorbing the neutrons themselves -- they bounce around, losing energy, until they can be absorbed by the core. Too little moderation, and the core won't start up. Too much moderation, and the neutrons will get absorbed and the core won't start up. The Chernobyl reactors were over-moderated, so that small voids in the graphite/water matrix in the core would increase the reactivity of the core. That's just stupid -- properly designed reactors are under-moderated, so that if the water boils the reaction tends to shut itself down.
Anyhow, all that would be moot except that the operators had disabled the main reactor shutdown mechanisms -- they couldn't SCRAM (or rapidly re-insert the rods into the core), but were forced to rely on the much slower drive mechanisms -- which couldn't contain the reaction. A rapid-drop SCRAM system existed (and would have saved the facility) but had been disabled for testing.
The problem (as I see it) with nuclear power is that people are such fuckin' idiots. Reactors are completely safe around people with what is called "common sense" but unfortunately, common sense isn't. Eventually, pointy haired bosses and Joe Sixpack rule the day.
(BTW, I hold a no-longer-current nuclear reactor operator's license).