One million years of isolation
January 4, 2010 8:09 AM Subscribe
An interview with Abraham Van Luik, US DoE geoscientist working on the nuclear waste repository under construction in Yucca Mountain.
At present, the political future of the Yucca Mountain project looks uncertain. However, the interview gives a good overview of the project itself, as well as the long-term storage situation worldwide.
As an added bonus, BLDGBLOG has done a smaller feature on natural nuclear reactors.
At present, the political future of the Yucca Mountain project looks uncertain. However, the interview gives a good overview of the project itself, as well as the long-term storage situation worldwide.
As an added bonus, BLDGBLOG has done a smaller feature on natural nuclear reactors.
Neat article. Dumb project, but if you set that aside it is an interesting engineering challenge, just in the abstract.
The way we (mis)use nuclear power currently, I think there's a fairly good chance that whatever we put into long-term storage we'll probably be digging up at some point in the future, so something like Yucca Mountain will never get close to the 10k year mark — to say nothing of a million years. The only reason the waste would ever need to be stored in its current form for that long is if we're all dead, and in that case I'm not sure why it matters how well it's stored.
Unprocessed "spent" fuel from PWR power stations doesn't even have all of its fissile fuel used up; a significant fraction of it is still there, 'poisoned' by the actinides which absorb the neutrons that the fuel needs to fission. Pull the neutron poisons out, and you can continue using the fuel.
The normal excuses against reprocessing — that it's a proliferation concern — seem a bit weak given that virtually every country with the capability of performing waste reprocessing also has nuclear weapons already (UK, France, India), or could have them if they wanted to in short order (Japan). That we would somehow be setting a "bad example" for the world by reprocessing is a bit silly, given that we have thousands of nuclear weapons sitting around — certainly if we were concerned about our nuclear reputation, that would be the major problem, not some hypothetical reprocessing proliferation concern.
And even without reprocessing, "spent" PWR fuel can be used in reactors of other types, with more favorable neutron economies. CANDUs, for example, are marketed for this purpose. As more CANDUs (or similar advanced reactors) are built — and China and India are in the market — we'll have more places for PWR fuel to go.
CANDU, as well as some other reactor designs, can also "incinerate" actinide wastes. Not burning in the literal sense, but bombarding them with neutrons by packing them alongside the fuel rods, accelerating their decay into stable end-products. While it's not practical to do this for all waste products and produce a totally inert result, it can be used to eliminate everything nasty with a halflife longer than 100 years or so. Suddenly, you don't need a 10k-year Mountain of Doom storage facility.
Yucca Mountain was and is an attempt to tiptoe around a problem the solution to which is staring us in the face, but we have shied away from using. Whether for political — mostly, proliferation — or economic — of course having the government bury your waste in the ground is cheaper than dealing with it properly — reasons, we've dropped the ball. Although it doesn't sound like any waste will ever be moved there, if we do go ahead and start burying our problems, I have confidence that our descendants will be coming back to clean it up in far less time than the designers are planning for.
posted by Kadin2048 at 8:47 AM on January 4, 2010 [12 favorites]
The way we (mis)use nuclear power currently, I think there's a fairly good chance that whatever we put into long-term storage we'll probably be digging up at some point in the future, so something like Yucca Mountain will never get close to the 10k year mark — to say nothing of a million years. The only reason the waste would ever need to be stored in its current form for that long is if we're all dead, and in that case I'm not sure why it matters how well it's stored.
Unprocessed "spent" fuel from PWR power stations doesn't even have all of its fissile fuel used up; a significant fraction of it is still there, 'poisoned' by the actinides which absorb the neutrons that the fuel needs to fission. Pull the neutron poisons out, and you can continue using the fuel.
The normal excuses against reprocessing — that it's a proliferation concern — seem a bit weak given that virtually every country with the capability of performing waste reprocessing also has nuclear weapons already (UK, France, India), or could have them if they wanted to in short order (Japan). That we would somehow be setting a "bad example" for the world by reprocessing is a bit silly, given that we have thousands of nuclear weapons sitting around — certainly if we were concerned about our nuclear reputation, that would be the major problem, not some hypothetical reprocessing proliferation concern.
And even without reprocessing, "spent" PWR fuel can be used in reactors of other types, with more favorable neutron economies. CANDUs, for example, are marketed for this purpose. As more CANDUs (or similar advanced reactors) are built — and China and India are in the market — we'll have more places for PWR fuel to go.
CANDU, as well as some other reactor designs, can also "incinerate" actinide wastes. Not burning in the literal sense, but bombarding them with neutrons by packing them alongside the fuel rods, accelerating their decay into stable end-products. While it's not practical to do this for all waste products and produce a totally inert result, it can be used to eliminate everything nasty with a halflife longer than 100 years or so. Suddenly, you don't need a 10k-year Mountain of Doom storage facility.
Yucca Mountain was and is an attempt to tiptoe around a problem the solution to which is staring us in the face, but we have shied away from using. Whether for political — mostly, proliferation — or economic — of course having the government bury your waste in the ground is cheaper than dealing with it properly — reasons, we've dropped the ball. Although it doesn't sound like any waste will ever be moved there, if we do go ahead and start burying our problems, I have confidence that our descendants will be coming back to clean it up in far less time than the designers are planning for.
posted by Kadin2048 at 8:47 AM on January 4, 2010 [12 favorites]
This place is a message… and part of a system of messages… pay attention to it!posted by anazgnos at 8:53 AM on January 4, 2010 [11 favorites]
Sending this message was important to us. We considered ourselves to be a powerful culture.
This place is not a place of honor…no highly esteemed deed is commemorated here… nothing valued is here.
What is here is dangerous and repulsive to us. This message is a warning about danger.
The danger is in a particular location… it increases toward a center… the center of danger is here… of a particular size and shape, and below us.
The danger is still present, in your time, as it was in ours.
The danger is to the body, and it can kill.
The form of the danger is an emanation of energy.
The danger is unleashed only if you substantially disturb this place physically. This place is best shunned and left uninhabited.
Inside of the square arrangement of berms, multiple granite “message kiosks” will be engraved with more basic information describing the site’s contents. This text will be provided in all of the official UN languages and Navajo (the local indigenous language). Additionally, space will be left on the kiosks for a future generation to inscribe the message in another language. The granite surfaces will be protected by a concrete “mother” wall, and the messages will be placed up high to prevent them from being defaced or buried by the desert sand.
It would be ironic if a nuclear waste site ever became a future civilization's deadly equivalent of a Rosetta Stone.
posted by Blazecock Pileon at 9:10 AM on January 4, 2010
It would be ironic if a nuclear waste site ever became a future civilization's deadly equivalent of a Rosetta Stone.
posted by Blazecock Pileon at 9:10 AM on January 4, 2010
As has been previously stated, the problem with all of those warning methods is that they could just arouse curiosity in anyone who finds them. Think about us with the pyramids--"Curse us forever? Haha! Ancient people!"
I can easily put myself in the shoes of someone discovering these markers and knowing nothing else about the place, and thinking "Let's go!"
Certainly an interesting problem. Hopefully it's not one we will actually have to solve.
posted by DMan at 9:12 AM on January 4, 2010
I can easily put myself in the shoes of someone discovering these markers and knowing nothing else about the place, and thinking "Let's go!"
Certainly an interesting problem. Hopefully it's not one we will actually have to solve.
posted by DMan at 9:12 AM on January 4, 2010
Is there a better solution available than Yucca Mtn?
Thorium (see also)
posted by Pollomacho at 9:18 AM on January 4, 2010
Thorium (see also)
posted by Pollomacho at 9:18 AM on January 4, 2010
That BLDGBLOG post is pretty interesting. I remember reading a science fiction novel that featured a natural reactor, but I can't put my finger on it. I think it was being used as a power source by people who didn't know how dangerous it was. Does anybody remember this?
posted by brundlefly at 9:22 AM on January 4, 2010
posted by brundlefly at 9:22 AM on January 4, 2010
Oops. I obviously meant the last BLDGBLOG post.
posted by brundlefly at 9:26 AM on January 4, 2010
posted by brundlefly at 9:26 AM on January 4, 2010
RussHy, from the article:
posted by kuujjuarapik at 9:27 AM on January 4, 2010
In the U.S., I would go either to North or South Dakota and look for the Pierre Shale, where it grades into clay: there, you get the best of both worlds. I have been quoted by MSNBC, much to the chagrin of my bosses, saying that, if I were to get the pick of where we go next, that’s where I would go. They really didn’t like that—I was supposed to praise the Yucca Mountain site. But let’s get real: Yucca Mountain was chosen by Congress. We have shown that it’s safe, if we do what we say in terms of the engineered system. But it was not chosen to be the most optimal of all optimal sites, the site-comparison approach was taken off the table by Congress. As long as a chosen site and its system are safe, however, that is good enough.
posted by kuujjuarapik at 9:27 AM on January 4, 2010
Brundlefly, I don't know about the fiction, but here's some non-fiction about a natural reactor.
posted by the painkiller at 9:29 AM on January 4, 2010 [1 favorite]
posted by the painkiller at 9:29 AM on January 4, 2010 [1 favorite]
Nuclear shit scares me.
From bombs to eternal toxicity.
DO NOT WANT!!!
posted by Windopaene at 9:41 AM on January 4, 2010
From bombs to eternal toxicity.
DO NOT WANT!!!
posted by Windopaene at 9:41 AM on January 4, 2010
Brundlefly - were you thinking of [WARNING SILVERBERG STORY SPOILER] this? I must have read that book a thousand times as a boy.
posted by Baby_Balrog at 10:35 AM on January 4, 2010
posted by Baby_Balrog at 10:35 AM on January 4, 2010
erm i see that you answered your own question an hour ago.
posted by Baby_Balrog at 10:36 AM on January 4, 2010
posted by Baby_Balrog at 10:36 AM on January 4, 2010
Thanks anyway, Baby_Balrog. Looks like your link's broken, though. What was it supposed to be?
posted by brundlefly at 10:39 AM on January 4, 2010
posted by brundlefly at 10:39 AM on January 4, 2010
Nuclear shit scares me.
Well if it SCARES you... obviously we ought to quit using it as a source of power.
Some more scary things:
Literacy: ideas are transmitted silently! What I write will survive my death and may be misinterpreted!
Photographs: is it my image or my soul that you have captured?
Genetically-modified crops: man was not meant to engage in selective breeding, I tell you!
Flight: if God wanted us to fly, he would have given us wings!
Blood transfusions: by sharing the essence of another, I lose my individuality!
Vaccines: you want to inject me with the blood of someone who almost died of smallpox? You're MAD!
This kind of emotive prejudice doesn't have a good track record.
posted by anotherpanacea at 10:46 AM on January 4, 2010 [18 favorites]
Well if it SCARES you... obviously we ought to quit using it as a source of power.
Some more scary things:
Literacy: ideas are transmitted silently! What I write will survive my death and may be misinterpreted!
Photographs: is it my image or my soul that you have captured?
Genetically-modified crops: man was not meant to engage in selective breeding, I tell you!
Flight: if God wanted us to fly, he would have given us wings!
Blood transfusions: by sharing the essence of another, I lose my individuality!
Vaccines: you want to inject me with the blood of someone who almost died of smallpox? You're MAD!
This kind of emotive prejudice doesn't have a good track record.
posted by anotherpanacea at 10:46 AM on January 4, 2010 [18 favorites]
Windopaene— why does it scare you so? Specifically nuclear energy.
Properly dealt with I don't actually see having nuclear waste as being a downside. With coal, oil and natural gas we're bellowing the waste (including radioactive material) into the atmosphere, whereas with nuclear we get a neat little lump of solid material that we can lock away for the eternity you mention.
Even looking back at our short history, it's clear that nuclear power has caused far, far less deaths then that of fossil fuels over the same time-period, so I'd suggest if you were to be scared of any particular energy source, you'd focus your fear upon fossil fuels.
posted by Static Vagabond at 10:49 AM on January 4, 2010 [4 favorites]
Properly dealt with I don't actually see having nuclear waste as being a downside. With coal, oil and natural gas we're bellowing the waste (including radioactive material) into the atmosphere, whereas with nuclear we get a neat little lump of solid material that we can lock away for the eternity you mention.
Even looking back at our short history, it's clear that nuclear power has caused far, far less deaths then that of fossil fuels over the same time-period, so I'd suggest if you were to be scared of any particular energy source, you'd focus your fear upon fossil fuels.
posted by Static Vagabond at 10:49 AM on January 4, 2010 [4 favorites]
Nuclear shit scares me.
From bombs to eternal toxicity.
DO NOT WANT!!!
At the risk of beating a dead horse, do you know what the by-product of burning coal is? It's nearly as toxic as nuclear waste. And they just put that shit into big piles sitting around outside without any protection or containment at all.
posted by GuyZero at 10:51 AM on January 4, 2010
From bombs to eternal toxicity.
DO NOT WANT!!!
At the risk of beating a dead horse, do you know what the by-product of burning coal is? It's nearly as toxic as nuclear waste. And they just put that shit into big piles sitting around outside without any protection or containment at all.
posted by GuyZero at 10:51 AM on January 4, 2010
Pollomacho: "Is there a better solution available than Yucca Mtn? Thorium (see also)"
Thorium isn't a panacea, despite some of its proponents (and that Wired piece was pretty breathless and had some exaggerated numbers in it). It produces waste products that are just as hazardous, if not worse, than uranium/plutonium cycle fission products. It's advantages are twofold: one, there's a lot of thorium in the world, particularly in places that don't have a lot of uranium (e.g. India); two, it's less conducive to having a weapons program than the uranium/plutonium cycle.
But the reason it's less conducive to bombmaking is because the U-233 (which, by itself, is a perfectly fine bomb material) is contaminated with U-232, which is a very dangerous gamma emitter and extremely difficult to separate out. You have to handle it with robots, versus plutonium that you can handle with rubber gloves. It's a hell of a tradeoff.
I don't think it makes a ton of sense from a nonproliferation perspective, because anyone capable of running a full thorium fuel cycle, at least in the near term, is almost certainly going to be able to make a bomb. (And the thorium cycle still gives you more than enough to make a hell of a dirty bomb, which in some ways are just as bad, if not worse, than an actual fission device.) Where they look particularly tempting is in parts of the world with lots of thorium and very little uranium: there, the possibility of total energy independence makes some of the difficulties of the thorium cycle worthwhile.
But for Western states that already have nuclear weapons and are sitting on lots of uranium — to the point where we're not even using it remotely efficiently — to say nothing of surplus plutonium from our bomb stockpiles, it doesn't seem hugely compelling.
posted by Kadin2048 at 11:22 AM on January 4, 2010
Thorium isn't a panacea, despite some of its proponents (and that Wired piece was pretty breathless and had some exaggerated numbers in it). It produces waste products that are just as hazardous, if not worse, than uranium/plutonium cycle fission products. It's advantages are twofold: one, there's a lot of thorium in the world, particularly in places that don't have a lot of uranium (e.g. India); two, it's less conducive to having a weapons program than the uranium/plutonium cycle.
But the reason it's less conducive to bombmaking is because the U-233 (which, by itself, is a perfectly fine bomb material) is contaminated with U-232, which is a very dangerous gamma emitter and extremely difficult to separate out. You have to handle it with robots, versus plutonium that you can handle with rubber gloves. It's a hell of a tradeoff.
I don't think it makes a ton of sense from a nonproliferation perspective, because anyone capable of running a full thorium fuel cycle, at least in the near term, is almost certainly going to be able to make a bomb. (And the thorium cycle still gives you more than enough to make a hell of a dirty bomb, which in some ways are just as bad, if not worse, than an actual fission device.) Where they look particularly tempting is in parts of the world with lots of thorium and very little uranium: there, the possibility of total energy independence makes some of the difficulties of the thorium cycle worthwhile.
But for Western states that already have nuclear weapons and are sitting on lots of uranium — to the point where we're not even using it remotely efficiently — to say nothing of surplus plutonium from our bomb stockpiles, it doesn't seem hugely compelling.
posted by Kadin2048 at 11:22 AM on January 4, 2010
Huh. Sorry bout that brundlefly - I had linked to Silverberg's Kingdoms of the Wall. I don't know why or how, but somehow that book absolutely transfixed me as a boy. I could not stop reading it, again and again, even after discovering Silverberg's other, better (imho) stuff.
posted by Baby_Balrog at 11:51 AM on January 4, 2010 [1 favorite]
posted by Baby_Balrog at 11:51 AM on January 4, 2010 [1 favorite]
“There were legitimate reasons to worry about nuclear power, but now that we know about the threat of climate change, we have to put the risks in perspective,” he says. “Sure, nuclear waste is a problem, but the great thing about it is you know where it is and you can guard it. The bad thing about coal waste is that you don’t know where it is and you don’t know what it’s doing. The carbon dioxide is in everybody’s atmosphere.” - Stewart Brand (see also: his awesome talk about Rethinking Green and going nuclear)
posted by blue_beetle at 12:00 PM on January 4, 2010
posted by blue_beetle at 12:00 PM on January 4, 2010
It's my understanding that we've been producing more nuclear 'waste' since the cessation of production of fissile materials for nuclear weapons. Not that stopping that is a bad thing. But now plutonium is, what, a byproduct? Or can't it be reprocessed? (Kadin2048, you're welcome to straighten me out here).
I heard a lot about fast neutron reactors a bit back. Doesn't seem to have gone anywhere.
The Russians have had some problems here too. I know the Ozersk 'Mayak' plant was reprocessing spent fuel, that place didn't, uh, work out so well in the past.
Looking at Yucca Mountain - I don't know. We have chemical separation plants and storage at Savannah River. It's got to go somewhere. A well engineered vault doesn't seem like a bad idea (stopping to make the stuff aside of course).
Yucca scares the hell out of me though. I suppose that's a good thing for future generations.
posted by Smedleyman at 12:48 PM on January 4, 2010
I heard a lot about fast neutron reactors a bit back. Doesn't seem to have gone anywhere.
The Russians have had some problems here too. I know the Ozersk 'Mayak' plant was reprocessing spent fuel, that place didn't, uh, work out so well in the past.
Looking at Yucca Mountain - I don't know. We have chemical separation plants and storage at Savannah River. It's got to go somewhere. A well engineered vault doesn't seem like a bad idea (stopping to make the stuff aside of course).
Yucca scares the hell out of me though. I suppose that's a good thing for future generations.
posted by Smedleyman at 12:48 PM on January 4, 2010
I don't think that the cessation of weapons manufacture in the US has that much of an impact on the waste stream from civilian plants. The military and civilian nuclear programs in the US have very little crossover at an operational level (except, recently, to take surplus weapons plutonium and make it into civilian reactor fuel).
Most of the plutonium used in the US nuclear arsenal was produced by reactors at the Hanford Site, many of which (the early ones) didn't produce any power at all — they just exhausted it as waste. Although later ones did produce power, it was sort of incidental to their real purpose, which was to convert U-238 to Pu-239.
The most common designs for commercial power reactors in the US are not very conducive to plutonium production. Although they do create Pu internally (due to neutron capture by U-238), most of it fissions off before the fuel is extracted. PWRs have long refueling intervals, and have to be shut down completely to remove any fuel. In contrast, plutonium producing reactors — including the ones at Hanford and some of the common Soviet designs (e.g. RBMK) — are designed to be refueled without a shutdown. This makes producing significant amounts of plutonium much easier.
Anyway, what plutonium does get created and left in the "spent" rods from US PWRs is not currently reprocessed. Right now, the spent fuel assemblies from power reactors are just stored on-site, with minimal reprocessing. At one point this was viewed as a temporary stopgap until a national reprocessing program was put in place, but that program never came. So the civilian reactors "burn" a load of lightly enriched uranium and then the whole assembly goes in the waste pile, until we decide to do something about it.
I suspect that the cessation of bomb production and the shutdown of the weapons reactors at Hanford has produced a substantial decrease in waste overall, just because it means fewer reactors in operation. Unfortunately, it also means shutting down the only facility in the country that's capable of and experienced at reprocessing spent reactor fuels. It would probably be better if Hanford were converted to civilian fuel reprocessing now that its bomb-factory days are over. Since it's unfortunately quite contaminated (mostly due to things that happened early on, before the technology was well understood) and is going to have to have people there monitoring it for years anyway, we might as well put it to some good use.
Now, in the former USSR, since they were reprocessing spent fuel from their power reactors,* the cessation of reprocessing for new bomb production has resulted in a pileup of waste. The plants weren't designed with as much storage capacity as they now require, and they're running out of room.
* There seems to be conflicting information on whether spent RBMK fuel was ever reprocessed. I find it hard to believe that its SNF was never meant to be reprocessed, because the Soviets had a pretty good grasp of the full nuclear fuel cycle and that just seems out of place in my understanding of their nuclear-power strategy (which viewed SNF as a national resource). But maybe they had plans to build a reprocessing facility and it was just never built, or it was reprocessed at one point and now isn't. SNF from one of their other common reactor designs is reprocessed, and they take back waste from plants located in former client states to a central facility.
posted by Kadin2048 at 1:51 PM on January 4, 2010 [2 favorites]
Most of the plutonium used in the US nuclear arsenal was produced by reactors at the Hanford Site, many of which (the early ones) didn't produce any power at all — they just exhausted it as waste. Although later ones did produce power, it was sort of incidental to their real purpose, which was to convert U-238 to Pu-239.
The most common designs for commercial power reactors in the US are not very conducive to plutonium production. Although they do create Pu internally (due to neutron capture by U-238), most of it fissions off before the fuel is extracted. PWRs have long refueling intervals, and have to be shut down completely to remove any fuel. In contrast, plutonium producing reactors — including the ones at Hanford and some of the common Soviet designs (e.g. RBMK) — are designed to be refueled without a shutdown. This makes producing significant amounts of plutonium much easier.
Anyway, what plutonium does get created and left in the "spent" rods from US PWRs is not currently reprocessed. Right now, the spent fuel assemblies from power reactors are just stored on-site, with minimal reprocessing. At one point this was viewed as a temporary stopgap until a national reprocessing program was put in place, but that program never came. So the civilian reactors "burn" a load of lightly enriched uranium and then the whole assembly goes in the waste pile, until we decide to do something about it.
I suspect that the cessation of bomb production and the shutdown of the weapons reactors at Hanford has produced a substantial decrease in waste overall, just because it means fewer reactors in operation. Unfortunately, it also means shutting down the only facility in the country that's capable of and experienced at reprocessing spent reactor fuels. It would probably be better if Hanford were converted to civilian fuel reprocessing now that its bomb-factory days are over. Since it's unfortunately quite contaminated (mostly due to things that happened early on, before the technology was well understood) and is going to have to have people there monitoring it for years anyway, we might as well put it to some good use.
Now, in the former USSR, since they were reprocessing spent fuel from their power reactors,* the cessation of reprocessing for new bomb production has resulted in a pileup of waste. The plants weren't designed with as much storage capacity as they now require, and they're running out of room.
* There seems to be conflicting information on whether spent RBMK fuel was ever reprocessed. I find it hard to believe that its SNF was never meant to be reprocessed, because the Soviets had a pretty good grasp of the full nuclear fuel cycle and that just seems out of place in my understanding of their nuclear-power strategy (which viewed SNF as a national resource). But maybe they had plans to build a reprocessing facility and it was just never built, or it was reprocessed at one point and now isn't. SNF from one of their other common reactor designs is reprocessed, and they take back waste from plants located in former client states to a central facility.
posted by Kadin2048 at 1:51 PM on January 4, 2010 [2 favorites]
RussHy Is there a better solution available than Yucca Mtn?
Put the nuke into orbit. It's the only way to be sure.
posted by Greg_Ace at 3:33 PM on January 4, 2010 [2 favorites]
Put the nuke into orbit. It's the only way to be sure.
posted by Greg_Ace at 3:33 PM on January 4, 2010 [2 favorites]
I was under the impression that nuclear waste is broadly divided into two categories: stuff with a short half-life and stuff with a really long half-life. The short half-life stuff is really nasty, but only for a short time (because of the short half-life), and that's not the stuff we're talking about putting in Yucca Mountain anyway. Then you have the stuff that's going in Yucca Mountain that will stay radioactive for 4 billion years or whatever, but that's not pumping out nearly as dangerous amounts of radioactivity because anything with a half-life that long must be decaying very slowly and thus producing relatively little radiation.
Now, it's been a long time since I took physics and I pretty much just picked this up from self-proclaimed experts on the Internet, so I'm open to any corrections. Obviously, even exposure to less-radioactive stuff can still be dangerous, but I thought that the stuff that's going to end up in Yucca Mountain is only really bad if you have prolonged exposure to it, and thus that a lot of the "sealed safely away in concrete for millions of years" hype about Yucca Mountain has a lot more to do with fears of nuclear energy than actual danger to people.
posted by Copronymus at 4:35 PM on January 4, 2010
Now, it's been a long time since I took physics and I pretty much just picked this up from self-proclaimed experts on the Internet, so I'm open to any corrections. Obviously, even exposure to less-radioactive stuff can still be dangerous, but I thought that the stuff that's going to end up in Yucca Mountain is only really bad if you have prolonged exposure to it, and thus that a lot of the "sealed safely away in concrete for millions of years" hype about Yucca Mountain has a lot more to do with fears of nuclear energy than actual danger to people.
posted by Copronymus at 4:35 PM on January 4, 2010
Copronymus: That's basically true, but there are a few additional factors that make some isotopes — even ones which aren't particularly radioactive in the decays/second sense — very dangerous. In addition to physical half-life, there's biological half-life: how long a particular isotope will stay in your body, causing various kinds of havoc, before you get rid of it. Also, some isotopes tend to concentrate in sensitive areas of the body, like bones or glands, where even a small amount of radioactive activity can ruin your day.
Iodine-129 has a halflife of ~120 Myrs, so it's not particularly radioactive (far, far less radioactive than Iodine-131, which is the one you'd take a "fallout pill" for in the event of nuclear attack). However, it's a significant waste concern because (like other iodine isotopes) it tends to concentrate in the thyroid and cause cancer. Technetium-99, another long-lived product, is also a concern, although I don't really understand the biological mechanism there. (I think it's an inhalation / lung cancer risk, but not sure.)
But as I noted earlier, there are reasonably practical methods available that would eliminate most of the really hazardous long-lived isotopes (I-129 and Tc-99 are the big targets) via neutron irradiation, substantially reducing the storage burden. There's likely to always be some amount of long-lived waste that it's better to keep under wraps, but it's nowhere near the volume that's being considered for storage (entire fuel assemblies) today.
It's entirely possible that, with a sane and well-implemented waste management program, you could get the total amount of long-lived waste down below the amount currently emitted into the environment by coal power stations — and instead of blowing it into the atmosphere, you'd have it all in a containable form. (Although from time to time I have heard people bring up the idea of pulverizing fission waste and blowing it up smokestacks at an equivalent level to that produced by coal burning, although thankfully not very seriously.)
posted by Kadin2048 at 9:39 PM on January 4, 2010 [1 favorite]
Iodine-129 has a halflife of ~120 Myrs, so it's not particularly radioactive (far, far less radioactive than Iodine-131, which is the one you'd take a "fallout pill" for in the event of nuclear attack). However, it's a significant waste concern because (like other iodine isotopes) it tends to concentrate in the thyroid and cause cancer. Technetium-99, another long-lived product, is also a concern, although I don't really understand the biological mechanism there. (I think it's an inhalation / lung cancer risk, but not sure.)
But as I noted earlier, there are reasonably practical methods available that would eliminate most of the really hazardous long-lived isotopes (I-129 and Tc-99 are the big targets) via neutron irradiation, substantially reducing the storage burden. There's likely to always be some amount of long-lived waste that it's better to keep under wraps, but it's nowhere near the volume that's being considered for storage (entire fuel assemblies) today.
It's entirely possible that, with a sane and well-implemented waste management program, you could get the total amount of long-lived waste down below the amount currently emitted into the environment by coal power stations — and instead of blowing it into the atmosphere, you'd have it all in a containable form. (Although from time to time I have heard people bring up the idea of pulverizing fission waste and blowing it up smokestacks at an equivalent level to that produced by coal burning, although thankfully not very seriously.)
posted by Kadin2048 at 9:39 PM on January 4, 2010 [1 favorite]
Is there a better solution available than Yucca Mtn?
Develop alternative and renewable energy sources. Consume less energy. Recycle high-energy goods, like plastic and aluminium.
posted by Blazecock Pileon at 9:45 PM on January 4, 2010
Develop alternative and renewable energy sources. Consume less energy. Recycle high-energy goods, like plastic and aluminium.
posted by Blazecock Pileon at 9:45 PM on January 4, 2010
Interesting interview. I found myself wondering while reading it why tectonic subduction zones are not being used -- why not let the earth swallow it over geological timescales? -- and discovered that it is banned by international agreement, although I'm still not clear on exactly why.
posted by stavrosthewonderchicken at 12:34 AM on January 5, 2010
posted by stavrosthewonderchicken at 12:34 AM on January 5, 2010
They still keep spent fuel at ECF in Idaho, apparently. Here's an interesting quote from that page apropos of this discussion:
posted by ctmf at 7:47 AM on January 5, 2010
How is Spent Fuel Stored at the INL?Also, if they get Yucca Mountain built and then decide not to use it: Dibs on the underground lair.
SNF is very "hot" when it is removed from a nuclear reactor—both "hot" as in hot to the touch (scientists call this thermal heat) and "hot" as in highly radioactive. It is typical practice to store SNF under water for a period of time after it is removed from a reactor so that water can provide cooling and shielding. Because the fuel normally loses about 99% of its radioactivity within a year of being removed from the reactor, wet storage is only required for about a year.
posted by ctmf at 7:47 AM on January 5, 2010
stavros - it looks like dumping in subduction zones is not specifically prohibited, but as nearly all accessible, safe, subduction-dumping sites are deep sea trenches it is banned because ocean dumping is banned:
However, this option has not been implemented anywhere and, as it is a form of sea disposal, it is therefore not permitted by international agreements.
posted by Baby_Balrog at 9:11 AM on January 5, 2010
However, this option has not been implemented anywhere and, as it is a form of sea disposal, it is therefore not permitted by international agreements.
posted by Baby_Balrog at 9:11 AM on January 5, 2010
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posted by rmd1023 at 8:36 AM on January 4, 2010