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Why don't we dispose of our nuclear waste by shooting it into space?
April 2, 2010 2:29 PM   Subscribe

Why don't we dispose of nuclear waste by shooting it into space?
posted by willie11 to Science & Nature (33 answers total) 6 users marked this as a favorite
 


I think the main reason is because launching things into space is still pretty risky and if anything goes wrong, it could open up high in the atmosphere leading to world-wide contamination.
posted by chillmost at 2:33 PM on April 2, 2010


Sometimes when we send things to space, they blow up by accident when they're in the air. If this happened with radioactive materials, I think we could contaminate a huge area, and make it uninhabitable, like Chernobyl.
posted by Sully at 2:33 PM on April 2, 2010


It's been suggested. The short version is "It's a great idea, except if it ever goes wrong, we've just dumped nuclear waste all over everything. Including nations that weren't stupid enough to put nuclear waste in rockets, which are now very very angry with us."
posted by Tomorrowful at 2:34 PM on April 2, 2010 [5 favorites]


Because it costs multiple thousands of dollars per pound to put anything into even a low-earth orbit. Digging a hole is much, much cheaper. (And, as others point out, there's also no chance of a launch vehicle malfunctioning and distributing the waste everywhere.)
posted by buxtonbluecat at 2:34 PM on April 2, 2010 [5 favorites]


The whole point to using nuclear power is it is cheap and efficient. You kind of lose that when you need to spend billions and burn millions of tons of chemical fuel on stuff you could just as well bury.
posted by floam at 2:36 PM on April 2, 2010 [1 favorite]


Another part of the equation is that getting something out of the Earth's gravity well is rather expensive, both in terms of energy and in money. Storing it is cheaper. Also, new technologies emerge which hint at the ability to reprocess "spent" fuel into something more useful.
posted by adipocere at 2:36 PM on April 2, 2010


Perhaps this video will answer your question.

Saladin, I would favorite that a thousand times if I could. And not just because I know you. Final Countdown!
posted by The Michael The at 2:40 PM on April 2, 2010


Also, new technologies emerge which hint at the ability to reprocess "spent" fuel into something more useful.

New? Hell, nuclear fuel reprocessing has been around since the late '40s.
posted by electroboy at 2:43 PM on April 2, 2010


Not that kind. I'm talkin' 'bout the reuse and/or burning in thorium reactors.
posted by adipocere at 2:50 PM on April 2, 2010


Sexy as the "danger of explosion" videos are, the real answer is "cost". You can always package the waste in hardened containers that will not be destroyed by an exploding rocket. But that costs money in turn - on top of the money it would cost to launch the rocket. Not financially feasible.
posted by VikingSword at 2:55 PM on April 2, 2010 [1 favorite]


Yes, yes. I understand that rockets occasionally blow up before existing the atmosphere. But what, if any, are the implications of sending spent nuclear fuel rods up in to space? How do they compare with current solutions such as burying waste in the desert? What is the cost/benefit? How expensive would it be to safely package the material and shoot it out to deep space vs. the expense of storing the spent nuclear material in waste pools like we do now or building long-term storage facilities like the one proposed for the Yucca mountains.
posted by willie11 at 3:03 PM on April 2, 2010


The correct answers have already appeared in the thread:

1. it is expensive (extremely)

2. it is unnecessary

3. it is wasteful (these are highly valuable elements)

btw, putting it into space doesn't mean much, it is very likely to come back, and dumping it into the sun or onto another planetary body, or even into a permanent parking orbit, are all actually enormously more expensive still, even if you ignore the other considerations.
posted by rr at 3:06 PM on April 2, 2010 [4 favorites]


What part of "It's Ridiculously Risky!!!" is unclear? Honestly, given the number of launches that have failed in history so far, I'd almost rather the stuff was stored in giant glass houses.

IMO, the real answer should be: dump them into empty salt domes. These have survived millenia, and are DEEP, so even if they are compromised by tectonics, they are unlikely to contaminate surface water.

There's not even a need to be orderly about it. Encase materials in concrete, transport, drop into drilled hole.
posted by IAmBroom at 3:12 PM on April 2, 2010 [1 favorite]


But what, if any, are the implications of sending spent nuclear fuel rods up in to space?

They could blow up. And it's expensive.

How do they compare with current solutions such as burying waste in the desert?

It is much more expensive and dangerous.

What is the cost/benefit?

Space = high cost, high risk, good benefit (material is not where anyone lives)
Desert = low cost, low risk, good benefit (material is not where anyone lives)

How expensive would it be to safely package the material and shoot it out to deep space vs. the expense of storing the spent nuclear material in waste pools like we do now or building long-term storage facilities like the one proposed for the Yucca mountains.

I don't mean to be flip with the above answers, but I think those portions of your follow-on question are answered pretty succinctly. This aspect of the question is far more interesting from an economic perspective, specifically the notion of marginal cost.

The marginal cost of a Yucca Mountain-esque storage system is very low -- you can always make the hole deeper, so to speak, for not much cost. The marginal cost of building rockets is very high -- the second and third rockets you build will be almost as expensive as the first. Sure, you'll get better at building rockets over time, but the cost of an equivalent amount of space in the hole in the ground is effectively zero.

Moreover, once the material is in space, it's GONE. Once the material is in a hole in the ground, if you wanted to, you could dig it back up. Let's say 100 years from now, a new fuel re-processing technique makes using waste as fuel a viable alternative. Where's the fuel? Well, it's in that handy-dandy hole in the ground.
posted by Cool Papa Bell at 3:14 PM on April 2, 2010 [1 favorite]


1) Staggering cost.
2) Outrageously dangerous.
3) Some of that waste is actually very rare and might be useful someday.
posted by chairface at 3:17 PM on April 2, 2010


How expensive is launching a pound of something into orbit?

According to this paper, generally, just to put it into orbit costs at minimum $4,000 a pound.

However, putting it into orbit makes no sense. You have to put it on an escape velocity from the Earth's gravity well to put it beyond the possibility of collision. My understanding is that the cost for that is multiples of that.

According to this page, the cost of disposing spent fuel on Earth is between $200 and $400 per Kg. No comparison.
posted by Ironmouth at 3:28 PM on April 2, 2010 [1 favorite]


Let's break it down. This paper gives the average cost to geosynchronous transfer orbit (not even close to deep space, it's still orbiting the earth) at $6,967 if you use a (potentially more risky) non-western rocket. Yucca Mountain was designed to hold 150 million pounds of spent fuel. To launch all that fuel into space, as cheap as possible, would cost $1 trillion. At about 11,000 pounds per launch, that would mean 13,636 launches into space. In comparison, the Total System Life Cycle Cost for Yucca Mountain was estimated at $90 billion, 9% of the cost of launching it all into space.
posted by zsazsa at 3:28 PM on April 2, 2010 [11 favorites]


Lovely zsazsa, thanks!
posted by willie11 at 3:40 PM on April 2, 2010


1) "Sending spent nuclear fuel rods up in to space" means different things. Do you mean low orbit? Geostationary orbit? Totally escaping earth's pull and continuing off into the universe? If something can still come back to earth, that's obviously a risk, even if it'll be up there for years, or thousands of years. Moreover, it's just something else that a satellite or astroid or future travel can smack into (unlikely, extremely so, but it's always a non-zero risk). In terms of totally escaping and going off into the universe, well, there's no implication to that (universe is very big), besides feeling bad that we're unable to deal with our shit so we're just tossing it into the void.

2) For the present day, launching shit into space doesn't even begin to compare with current waste solutions, because ...

3) Holy jeeze is space flight expensive. American commercial reactors alone produce more than 3,000 tons of the stuff each year. As a very rough estimate, Virgin Galactic is selling flights on SpaceShipTwo for $200K each. Let's say that the average person is 150 pounds. That's $1,300 per pound to get into the very lowest realm considered "space." So, 1300*2000*3000 = 8 billion dollars a year to get up our commercial reactor waste up to bare-bones low earth orbit, which would be ...

4) Politically unacceptable. Normally, a rocket exploding is a tragedy. A rocket exploding filled with thousands of pounds of nuclear waste would be a fucking nightmare. Safety measures add cost to everything. By the time that shooting nuclear waste into space is economically feasible, I imagine we'll have lots more to worry about, like what to do now that we've evolved into being of pure energy and thought, because it's the year 3000.
posted by Damn That Television at 3:44 PM on April 2, 2010 [1 favorite]


Funny, when I was in 5th grade, I asked my science teacher this exact question. Her response:

"That would be unethical, because it might someday land on an alien planet and ruin their environment."
posted by notswedish at 3:59 PM on April 2, 2010 [10 favorites]


Notswedish's answer makes sense if you ignore the costs of launching it into space.

I wonder what would happen if it was sent up to high orbit and allowed to incinerate itself on re-entry? What does burning spent nuclear rods produce?
posted by gjc at 4:04 PM on April 2, 2010


One other perspective is to realize, that for some long-lived spacecraft, we and the Russians have, for many years, launched small plutonium radioisotope thermoelectric generators (RTGs) into space, where they power deep space probes for many years from the decay heat of enriched plutonium sources, when no other power source will readily do. And yet, even for the relatively small amounts of radiation such thermal sources contain, considerable engineering effort and packaging expertise goes into assuring that the radiation sources cannot become exposed to the environment, even in the heat of re-entry. Packaging even diffuse radioactive sources for survival of accidental conditions adds a lot of weight, and therefore cost, to the package. And even then, it hasn't always worked.

Packaging nuclear waste to the same standards wouldn't be feasible from an engineering or cost standpoint, for any system using chemical rocket boosters.
posted by paulsc at 4:17 PM on April 2, 2010


What does burning spent nuclear rods produce?

Radioactive gas and ash.
posted by flabdablet at 4:26 PM on April 2, 2010


Sorry, just in case this wasn't clear: the ash is radioactive too.

Burning things is a chemical process, and makes no difference at all to its nuclear properties.
posted by flabdablet at 4:28 PM on April 2, 2010


Do we even have many rockets that are capable of launching things out of earth orbit? We haven't even launched that many probes, most of what we put up goes into orbit, and eventually comes back down. Just a few probes are sent out of orbit.

It would probably possible to do safely, we have containers that can survive huge train crashes, for example. And we do send up RTGs into space with lots of nuclear fuel to power space probes. But the real problem would just be the expense. Burying it does work, and it's cheap.

"That would be unethical, because it might someday land on an alien planet and ruin their environment."

By the time it reached its destination, it would probably have decayed. When the earth was formed, there was a lot of radioactive material, so much so that there were already self-sustaining nuclear reactions going on. But over the billions of years, that's no longer possible, because the nuclear fuel that would have fired in them has all decayed.
posted by delmoi at 4:33 PM on April 2, 2010 [1 favorite]


Don't get hung up on rockets. The smart way to do this would utilize a magnetic linear accelerator up the side of a mountain. And the target wouldn't be deep space; rather, the solar gravity well, so the cans of waste would drop into the sun. "But the waste would hurt the sun, maybe!"
posted by Rash at 4:52 PM on April 2, 2010 [1 favorite]


It'll be a lot cheaper and safer once we have a space elevator. But the main thing is we (Americans) should stop hiring incompetent assholes to build and run power plants and hire the French instead :)
posted by Salvor Hardin at 5:02 PM on April 2, 2010 [2 favorites]


Because its expensive.

The only things that go into space now are:

1. research which has already been paid for, is being paid for by rich companies, or being paid for by a government.

2. Commercial stuff from companies that stand to gain WAY more than they lose in sending something up into orbit (satellites, cameras, etc).

Getting rid of waste is kinda expensive (as the payload will be heavy)...and people who want to get rid of the stuff feel its a lot easier to buy land from govts, people, and other companies and put it in the ground there. A LOT cheaper.

Thats all.
posted by hal_c_on at 7:12 PM on April 2, 2010


Although you wouldn't launch nuclear waste to the Moon, this makes you go hmm. Even if something escapes the Earth's gravity well, it might return one day.
posted by lukemeister at 9:19 PM on April 2, 2010


Say what you will about the limitations of current technology to do this, but I'll always hold onto a pipe dream of a thorium-reactor driven mass driver launching spent fuel into the heart of the sun.
posted by truex at 12:16 AM on April 3, 2010 [1 favorite]


I'd almost rather the stuff was stored in giant glass houses.

Interestingly, the cases used to store the rods are made of very thick glass which is then covered in other materials.
posted by odinsdream at 10:29 AM on April 3, 2010


It would not make economic sense to send slightly contaminated waste into space, which can reasonably go into shallow land controlled burial. Extremely long-lived isotopes &/or high activity waste might be candidates, except that for fairly obvious reasons, you would want to minimize volume/weight to the greatest extent possible in order to dispose of as much as possible per payload. What did get sent would therefore need to be greatly concentrated in order to get the max curie content out per volume - now you're into the equivalent of spent fuel reprocessing - very expensive to build and operate these processing systems.

Concentration will significantly raise the specific dose rate/field around the waste container(s). Now you may need to be worried about increased dose effects on system electronics - shielding (lead, concrete, wax, oil, etc.) may be needed, which would add additional volume/weight, negating some of the benefits of concentration. While there may be some happy median/economic equililibrim point, the fact is, it'll be more expensive up front than keeping it in earth-bound storage/disposal.

Highly radioactive RTGs (radioisotope thermoelectric generators) get sent up all the time, particularly for satellites and trans-solar craft. We can argue about the relative merits of the Environmental Impact Statement analyses that 'demonstrate' their probable survivability from reentry & impact, but for rad waste - there's just too much of it to make transorbital disposal viable.
posted by Pressed Rat at 12:57 PM on April 3, 2010


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