Getting Energy from Chernobyl

[Hal]

To start this off, I want to apologize for any painful ignorance I have on this topic, radiation isn't something I know an awful lot about.

What I do know, though, is that the Chernobyl disaster left a good deal of land uninhabitable for hundreds if not thousands of years, and the inside of the reactor that melted down is still incredibly radioactive. I also know that this is ionizing radiation, which is much more powerful than the normal radiation we get from the sun (duh, that's why it kills people). I'm sure there's some rather obvious explanation to this, but why can't we try to harness the energy from all that radiation? Inside the reactor, there's enough to kill a person very quickly, which (I think) takes a pretty non-insignificant amount of energy, so why isn't this possible? Or if it's possible, why isn't it done? Is it not actually worth it?

[Brethern]

Probably because it's uncontrollable,

trying to harness it's energy is like using a flame thrower to charge a solar powered calculator.

[sgt_flyer]

Well, i guess that it could be technically feasible to extract electricity from those - one of the problems will be that the elements you'll have (and need to place very close to the reactor) would become radioactive and deteriorate at a substantial rate, so you'll need to change those regularly, and treat them as nuclear waste too.

That said, they continued to use Chenobyl's NPP other reactors for a long time after the accident - and it wasn't the only accident that happened there.

Comissioned in 1977 , it seems Reactor 1 had a partial meltdown in 1982 (reactor was repaired) -

in 1986, the disaster - Reactor 4 explosion

They continued operations with the 3 other reactors - reactor 2 was shutdown in 1991 after a fire broke out in the turbine's hall, and they stopped reactor 1 and 3 in 1996 and 2000.

For now, given the state the current sarcophagus is in, you'll have to wait for the New Safe Confinment to be built, and the various remainsof the old sarcophagus / building to be cleared before any experiment could take place

And reactor 4 is much less hot (in temperatures and radiations) than what it was during the disaster. (During the disaster, they feared that the reactor could melt it's way through the earth... Where it could have poisonned some underground water supplies) the liquidators and firefighters dropped lot of things on the reactor - a good part of it was moderator to slow down the reactions.

So, all in all, it's maybe technically feasible, but it would not be useful. (Too much hassle for not enough returns)

Edited September 11, 2014 by sgt_flyer

[Hal]

Cool, I figured it was something like that, but it's nice to know for sure. I didn't think of the power generating... things decaying themselves. Thanks.

[Guest]

Actually, we were getting energy from Chernobyl until 1990. Why until then? Well, turns out that that's the year the plant was actually shut down. They had three more reactors, and they kept them running and staffed until 1990. One even had a partial core meltdown and other a fire in the turbine hall...

Also, by now, radiation isn't the biggest problem around the area. It's actually pretty weak, aside from the most irradiated zones, it's hardly dangerous. The area is cordoned off mainly because it's ecosystem is so incredibly unique that it'd be a shame to let people back in and destroy it.

[sgt_flyer]

Well, they researched using thermophotovoltaics to enhance RTG thermocouples, and the degradation of the thermophotovoltaïcs cells was one of the huge constraints, plus the materials needed are not cheap so while 'cheap' is not really a factor if they could decrease the amount of Pu238 for a RTG powered mission, the fact that the cells could degrade over time (and, i think, faster than the Pu238 half-life) would make this technology not really suitable for long duration missions (which kinda defeats RTG usage ) at least, with current materials. The reverse would be true on chernobyl : we would be able to change the cells on earth, but their cost would make it prohibitive compared to the gains

[Wanderfound]

May be of interest; a not-too-technical explanation of what happened.

http://www.stacken.kth.se/~foo/texts/chernobyl.html

And for a little bit more detail: http://www.unscear.org/unscear/en/chernobyl.html

Edited September 11, 2014 by Wanderfound

[Aethon]

Generally we get nuclear power in a very old fashioned way, using it's ever present heat to boil water to spin a turbine- basically 1800's technology. It would be nice if we could just 'soak up' the radiation and convert it to usable energy though.

[gooddog15]

Generally we get nuclear power in a very old fashioned way, using it's ever present heat to boil water to spin a turbine- basically 1800's technology. It would be nice if we could just 'soak up' the radiation and convert it to usable energy though.

if we could soak up radiation, nuclear waste wouldn't be unusable after all.

[Nibb31]

A nuclear plant works by using the heat from the nuclear reaction to boil water. The steam runs turbines. The turbines produce electricity. It's not really different from a coal plant or an oil plant, where they burn stuff to produce heat.

The problem with Chernobyl is that all the stuff around the core that is used to pump and circulate water was blown away and that the melted core doesn't produce enough heat any more. It would be pretty useless.

[einsteiner]

The problem with Chernobyl is that all the stuff around the core that is used to pump and circulate water was blown away and that the melted core doesn't produce enough heat any more. It would be pretty useless.

I think you've hit it on the head. It's like trying to use the embers from last night's camp fire to cook. They're still hot enough to be dangerous, but not hot enough for any practical purpose.

[Nuke]

alpha/beta voltaic cells are a thing, but they tend to be very low power devices.

it might be better just to recover the fuel, but that requires digging up the core, which would likely be a very hazardous and expensive affair. and what you get out of that is essentially high level nuclear waste, you might be able to feed that into a modern reactor and use it as fuel. but its probibly better off staying where it is. there are much safer/cheaper ways to get nuclear fuel.

Edited September 11, 2014 by Nuke

[lajoswinkler]

This is the current state of the reactor building. (the two white things on the tilted Upper Biological Shield are neutron counters)

The orange stuff is the solidified mass that, once molten and glowing incadescently and now pretty cool, oozed from the reactor and flowed through pipes to the basement. It is impossible to get near them without getting a lethal dose of ionizing rays.

Power output of those masses probably isn't enough to power a large household, but it's enough that, when such energy is given to subatomic particles and photons, they become like little knives that wreck our cells, mostly by ionizing water inside them (ions and radicals then destroy cellular machines).

Compare it to Large Hadron Collider. A single proton in the proton ray has almost the power of a small mosquito. That's ok for a mosquito, pathetic for a cat, but insane for a proton.

Basically, we can do nothing with that solidified mass except entomb it. It's not radioactive as it used to be (radioiodine is gone), but it's probably still potent enough to wreck even rad-hardened electronics in robots that would have to work with it. It would have to be cut with diamond blades, and the resulting radioactive dust would coat everything and wreck the electronics.

[einsteiner]

This is the current state of the reactor building.

That's a neat model, where did you find that?

[lajoswinkler]

That's a neat model, where did you find that?

Search for chernobyl model. It's a model in the lobby of the Chernobyl power plant.

It's meticulously accurate, for what I've noticed while looking at the actual photos.

Edited September 11, 2014 by lajoswinkler

[pizzaoverhead]

http://www.blackrosetech.com/gessel/wp-photos/20110622-080113-5.jpg

Nice use of an old door mat for the mangled fuel rods! The model gives a great sense of the scale of the damage.

One of the other issues with doing anything other than boxing up the reactor is that it is contained in a structurally unsound building due to the steam explosion. Note the angled walls:

The upper biological shield in particular (the highly-angled thick green section in the middle) weighs around a thousand tons, and is supported only by debris, due to being lifted and flipped nearly upside down by the explosion. If it were disturbed and fell, it would move a large amount of dust out of the building.

The red areas are the radioactive materials, and consist of a lava of melted fuel rods, control rods, piping, concrete, steel girders and assorted debris which is sometimes called Corium. A lot of it settled inside the various pipes connected to the reactor before hardening. One of the more famous formations of corium has been named the Elephant's Foot, discovered hardened after leaking out of a pipe in the lower sections of the building:

Lumps of radioactive rusty concrete like this are difficult to use for boiling water as they aren't pure enough to produce the heat required.

Edited September 11, 2014 by pizzaoverhead

[lajoswinkler]

LOL, it is an old mat, isn't it?

The guy in the photo was playing with his life. Half a minute longer and he would probably be a goner. I've heard they were taking such photos at extreme hurry.

Few centimetres closer and the dose is already stupendous. Approaching it at 10 cm would kill in minutes.

Good thing about uranium, which is mildly radioactive, is that it is itself a great shield, better than lead, so all the fission products inside can't deliver their maximum potential. If there was just a pile of compounds of fission products, no one would be able to approach it at 10 m or more, and the air close to the surface of the pile and the compounds themselves would probably have a radioluminescent glow.

The problem is that in hot and humid environments of the flooded basement the mixture of UO₂, steel and other crap will react and form various salts. That's why the "foot" turned yellow. The yellow stuff is flaky and that's not something anyone wants...

[-Velocity-]

To start this off, I want to apologize for any painful ignorance I have on this topic, radiation isn't something I know an awful lot about.

What I do know, though, is that the Chernobyl disaster left a good deal of land uninhabitable for hundreds if not thousands of years,

Tell that to the millions of wild animals that call the thriving wildlife preserve around Chernobyl home. Yes, Earth life is thriving the in lands surrounding Chernobyl. For example, one of the largest populations of an endangered species of wild horse calls these "uninhabitable" lands home. Two reasons for this

1) The biggest threat to many species is simply human encroachment, poaching, accidental or collateral deaths, and habitat loss. Humans are a hell of a lot worse than some slight residual radiation.

2) Wild animals don't usually live long enough to develop cancer. Cancer tends to strike the elderly, and elderly wild animals simply die from other causes because they become unfit for survival.

Continuing...

and the inside of the reactor that melted down is still incredibly radioactive. I also know that this is ionizing radiation, which is much more powerful than the normal radiation we get from the sun (duh, that's why it kills people). I'm sure there's some rather obvious explanation to this, but why can't we try to harness the energy from all that radiation? Inside the reactor, there's enough to kill a person very quickly, which (I think) takes a pretty non-insignificant amount of energy, so why isn't this possible? Or if it's possible, why isn't it done? Is it not actually worth it?

There isn't much energy there. During the early years, they did have occasional overheating issues (heat was not being sinked out of the decaying radioactive debris fast enough), but those short-lived products have largely decayed now. Secondly, why try to harvest that energy? Do YOU want to go lay pipes to run water through that radioactive rubble? It probably doesn't even get hot enough to boil water anymore, though maybe there are lumps that are still that hot. I donno.

Secondly, as you said, it's IONIZING radiation. Just because it can kill you doesn't mean it's a lot of energy. For example- stand outside under the sun. You're being irradiated with ~1000 W/m^2, mostly in visible light and infrared. Individual photons at these wavelengths of light are not powerful enough to break molecular bonds- they are not ionizing radiation. A small amount of solar energy consists of ultraviolet wavelengths. Ultraviolet photons ARE powerful enough to break molecular bonds. Frequently, an ultraviolet photon will break the bonds holding together one of your DNA molecules in your skin. 99.9999% of the time, your body is able to successfully repair this DNA damage. Sometimes, however, the DNA repair mechanisms all fail and the messed up DNA starts making the cell behave erratically. I believe the body has additional redundancy to deal with malfunctioning cells- I believe there are self-destruct and immune response triggers, but I can't remember. (A living cell is a fascinating piece of "nanotechnology".) However, sometimes, ALL those mechanisms fail, and the cell starts reproducing out of control. You get cancer. Despite the effectiveness of the body's DNA repair and malfunctioning cell eradication mechanisms, you have A LOT of cells, so chances are quite good that eventually you'll get cancer. The more DNA damage you accumulate, the higher the chances that you'll get it.

Now, remember that sunlight that was 1000 W/m^2 of mostly harmless radiation? Now imagine that that's 1 W/m^2 of gamma rays- incredibly energetic photons that can just decimate a complex molecule, and pass right through your skin, doing their damage deeper inside your body. It wouldn't take long, even at that to take a lethal dose of radiation where so many cells in your body take severe radiation damage to their DNA that you die in a week or two.

Even worse than gamma rays, imagine that you are being exposed to neutron radiation. Being electrically neutral, the neutrons stream into you, right through your skin, strike the nucleus of an atom, and then make a shower of energetic particles that rip through your body like subatomic shrapnel, ripping apart any biological molecules they find.

Anyway, understand the difference-

Non-ionizing radiation (electromagnetic radiation at visible light wavelengths and below) just makes you hotter if you absorb it. It can even be good for you.

Ionizing radiation (high energy electromagnetic radiation, alpha particles, beta particles, neutrons, etc.) BREAKS UP THE MOLECULES THAT COMPOSE YOUR BODY. Bad. VERY bad.

So just because a place contains a dangerous amount of ionizing radiation doesn't mean there's much energy there. It's just that the type of energy that is there is of a type that is very hazardous to the biological molecules we are composed of.

Edited September 11, 2014 by |Velocity|

[lajoswinkler]

Just to clarify a bit - ionizing radiation rarely strikes important molecules in the body. The odds of a particle hitting exactly in the atom or even nucleus of something important, are negligible, basically zero. Most of the cell matter is water.

If they collide at all (most of them, especially gamma, passes through us like we're nothing), it will be with water. Energized molecule of water will decompose into energized radicals which rip apart other water molecules and it goes on. The "wave" of ripping is spreading until the energy is lost. It can be lost by dissipation, but most often a great deal of it is spent on reactions with organic molecules. We do have specialized enzymes which deal with radicals, but sometimes they aren't nearby or the energy is too concentrated, so some of the radicals rip apart the enzyme, or even DNA. If the cell doesn't fix the damage, it either says "I'm crap, imma gona kill myself now" (apoptosis) or errors get shown as various mutations. Maybe silent mutations, maybe aggressive cancer which can be faster than your immune system and spread around.

[vetrox]

A quick search about the 'elephants foot' will point you in the right direction. Reactor 4 suffered a meltdown. Contrary to popular belief a meltdown isn't a nuclear bomb/mushroom cloud stylee explosion. The fuel ( which had no coolant) quite literally melts under its own heat. Melts through the floor and slowly making its way to the depths of the earth.

Now the material has long since lost ( most of) its heat and is just a big super heavy pile of lethal waste fuel and debris. Without the heat needed to dip it into a steam turbine ( let alone it's crazy super heavy miss shapes state) makes the melted fuel useless for further use as a fuel.

Hope it helps. I'm no scientist but I was on a mad Chernobyl craze a year back. Here's a fun link http://m.nautil.us/blog/chernobyls-hot-mess-the-elephants-foot-is-still-lethal

Edit: boy, does typing stuff on the phone make u late to the party

Edited September 11, 2014 by vetrox

[Stargate525]

If the cell doesn't fix the damage, it either says "I'm crap, imma gona kill myself now" (apoptosis) or errors get shown as various mutations. Maybe silent mutations, maybe aggressive cancer which can be faster than your immune system and spread around.

A little off-topic, but that's what Cancer is; a failed 'imma gona kill myself now' button.

[TheGatesofLogic]

Generally we get nuclear power in a very old fashioned way, using it's ever present heat to boil water to spin a turbine- basically 1800's technology. It would be nice if we could just 'soak up' the radiation and convert it to usable energy though.

boiling water reactors haven't been actively made since the early sixties... They are not very effective for nuclear energy actually, and they are very dangerous. The same applies to almost all power plants too, pressurized water reactors are orders of magnitude more efficient.

[sgt_flyer]

Well, current reactor temps are really low - the pressurized water coming out of the exchangers is generally at 450 degrees celsius - the elements in the fuel rods maybe at 600 degrees celsius. However, given those temps, secondary circuits steam temperatures are equally low - simply because the fuel rods (+ te graphite moderators) are not meant to support such high temperatures.

As in order to protect the fuel rods, we can't have high temperatures, we have to use very inefficient steam turbines. : the water temperatures are not hot enough to allow the usage of high efficiency turbines. (Though, given the efficiency of the fuel, this still make nuclear reactors very efficient in terms of fuel usage for the electric power generated)

Higher temperature reactors (like gas core or molten salt designs) would allow to use Brayton cycle turbines (more than double the efficiency of steam turbines) so basically, less thermal power / fuel is needed to achieve the same electric power outputs)

Anyway, we really should move away from current solid fuel rods - in addition to not be able to support high temperatures, those are a terrible waste of fissile material (once a fraction of the fissile material in the rod has been transmuted through the nuclear reactions, the rod becomes useless - even if it still contains usable fissile material (because the ejected neutrons would not be able to sustain the reaction if they are catched by the waste products) - and has we can't extract the viable products from the used fuel rods (too dangerous) - then the whole thing is discarded as waste.

Edited September 11, 2014 by sgt_flyer

[lajoswinkler]

Actually, we can extract fissile material and it's routinely done in some countries. Plutonium and uranium aren't even separated because they don't have to be. The new fuel is called MOX (mixed oxides). You can do that on and on, every time enriching the product a bit with fresh uranium.

[SorryDave]

It is quite possible to extract energy from any nuclear pile and nearly any heat source warmer than the environment.

But, It is not economically feasible and the risk to life is high.

It would be better to spend the money on solar panels.