Storing Nuclear Waste on the Moon

[gmalivuk]

Ooh, one whole data point to show that launching waste into space might be safe! I'm impressed!

[Eebster the Great]

So you present the worst case scenario for waste leaking in a mine, but what about the worst case scenario of launching the waste into orbit? Like the launch vehicle exploding and spreading radiation over some otherwise populated area. Or the thing crashing into some watershed or other populated area.

Rockets are not launched over populated areas, most of them are launched over the ocean. The worst case is godzilla some dead fish, in the incredibly unlikely event that both rocket and spacecraft fail at the same time. See the Falcon 9 explosion for example: The capsule survived an explosion of the full upper stage, even without a launch abort system.

It could also explode on the launch pad. Even if it doesn't kill anybody, it still has some impact on the environment. The question is if this is less than burying the waste miles underground. And don't forget the carbon dioxide produced by the rockets. Again, that would be considerably more per ton of waste than transportation to a ground-based facility.

This idea doesn't have to be very dangerous to still be more dangerous than conventional storage.

[mfb]

Ooh, one whole data point to show that launching waste into space might be safe! I'm impressed!

No. Thousands of rocket launches show that. We can just learn most about the risks from the most dangerous situations - like the Falcon 9 rocket explosion.

It could also explode on the launch pad.

Launch abort system.

And don't forget the carbon dioxide produced by the rockets.

Completely negligible (and you can produce the fuel for them with electricity from nuclear power if you want - fully CO2-neutral).

This idea doesn't have to be very dangerous to still be more dangerous than conventional storage.

Great? If storing it underground is safer than a system where you wouldn't expect any accident while discarding the whole waste, then the technical problem is solved.

[gmalivuk]

Ooh, one whole data point to show that launching waste into space might be safe! I'm impressed!

No. Thousands of rocket launches show that.

Those thousands of launches haven't all been successful, though. And a failure with nuclear waste is rather more significant than a typical failure, even if we include minor things like failure to reach quite the target orbit.

[DaBigCheez]

Can confirm that even using very well-vetted launch systems for relatively routine tasks (taking satellites to GEO), the accident rate is *very* non-trivial. A quick glance at the insurance rates for orbital launches can tell you that much - or, for that matter, the fact that insurance is a part of the process at all.

[morriswalters]

The sheer mechanics of doing this should boggle the mind. The type of waste that is most dangerous is the heaviest and the most difficult to maintain safely, used fuel rods. They store used fuel rods in cooling tanks on site at the facilities or they use dry cask storage. And it take years to get it cool. To launch it into space you will have to shield it. The weight of what you have to launch would mean a heavy booster of some type. The material has been accumulating for years. You could consume all the engines we could build for some span of time. It would drive the costs of all launches up. Creating a cask that could survive a severe launch failure would increase the weight even more.

Here's something from The World Nuclear Association. Interesting tidbit.

The IAEA has regularly issued revisions to the transport regulations in order to keep them up to date. The latest set of Regulations for the Safe Transport of Radioactive Material is the 2012 edition.

The objective of the regulations is to protect people and the environment from the effects of radiation during the transport of radioactive material.

Protection is achieved by:

Containment of radioactive contents.
Control of external radiation levels.
Prevention of criticality.
Prevention of damage caused by heat.

The fundamental principle applied to the transport of radioactive material is that the protection comes from the design of the package, regardless of how the material is transported.

[p1t1o]

Rockets are not launched over populated areas, most of them are launched over the ocean. The worst case is godzilla some dead fish, in the incredibly unlikely event that both rocket and spacecraft fail at the same time. See the Falcon 9 explosion for example: The capsule survived an explosion of the full upper stage, even without a launch abort system.

So what Im hearing is: we should just skip the middle man and dump it straight into the ocean?

[WibblyWobbly]

We should get some of that unobtanium stuff from the movie "The Core" and use that as a vessel for our nuclear waste, then drop it in the Challenger Deep and forget about it.

[Eebster the Great]

It could also explode on the launch pad.

Launch abort system.

Sure, I get that safety measures exist. So far, this system has fulfilled its purpose once. It has failed once. That's not a reassuring success rate. We know that the rate of failure of these systems in practice tends to be much higher than in test conditions.

And don't forget the carbon dioxide produced by the rockets.

Completely negligible (and you can produce the fuel for them with electricity from nuclear power if you want - fully CO2-neutral).

Who says it's negligible? You are proposing this is how we handle all of our waste. And if we aren't going to use kerosene, that just pushes the cost even higher.

This idea doesn't have to be very dangerous to still be more dangerous than conventional storage.

Great? If storing it underground is safer than a system where you wouldn't expect any accident while discarding the whole waste, then the technical problem is solved.

Yes, storing it underground is safer than a system where you launch it into space. The technical problem is indeed solved. The political problem, however, remains.

[LaserGuy]

Something to keep in mind for those of you who want to put this stuff into orbit: We have 250,000 tonnes of nuclear waste, and produce a few thousand tonnes per year. The entirety of all material that we have put into space, in all of human history, is somewhere in the neighborhood of 10,000-20,000 tonnes. So we aren't just talking about a small increase in our payload... we're talking about a massive industrial, continuous rocketry project that would involve launching more material into space that we have in our entire history every couple of years--and that's just to keep up with current waste production, nevermind the backlog of material we already have. This doesn't include the weight of the rockets themselves, which is certainly non-negligible as well, since that contributes to how much fuel you'll need--something well upwards of 2.5 million tonnes of it.

[Zamfir]

I tried to put some numbers on this.

Starting point is this: http://www.neimagazine.com/features/featuredeveloping-a-spent-fuel-cask-for-air-transport-4210559. It's a container to transport spent fuel by plane, designed to survive falls from high altitude. Add heat shielding to survive uncontrolled reentry, and you'd get an idea how rocket transport might look like.

That TUK145 container weighs 30 ton, to transport half a ton of spent fuel. A Saturn V rocket could lift 50 ton to the moon Let's assume that is enough for a reentry- shielded container. Give us 2 SaturnV-sized missions per ton of spent fuel.

Yearly nuclear fuel consumption is somewhat over 2000 ton, with a spent fuel backlog of decades. Let's say we want to get rid of 3000 ton each year to eat away the backlog.

Reprocessing can reduce that 5-fold by removing most of the uranium, selling the plutonium, then making glass of the remaining concentrate. Perhaps they can do 10-fold or more if really necessary, but that's a guess from my side and might carry a hefty price tag.

At that assumed 10-fold 'concentration', we're talking 600 launches a year, compared to 100/year today (none of them even approaching Saturn V scale). This scheme would dwarve current space activity.

Next, cost. Yucca Mountain was to be financed from a 0.1 $ct/kWh levy. I have seen similar costs elsewhere for underground storage, slightly higher as well. Assuming 50gwd/ton thermal burn-up , that gives us somewhat below half a million dollar per ton. With the 10-fold reprocessing concentration (which has to be paid from that same money), we get 2.5 million dollar per launch. I think we can rule this out for the foreseeable future. 1ct/kWh might still be bearable, that gives us 25 million per launch. Perhaps vaguely plausible. At this moment, a SaturnV-sized launch (or multiple smaller launches) would be bargain at 10 times that.

Last, safety. At current failure rates, we would expect to see multiple catastrophic launch failures each year. I can't imagine that this is acceptable, even with a heavy container as backup. That air transport container above is designed on the assumption that air crashes are already vanishingly rare - not every few hundred flights. At a wild guess, you'd need a hundred-fold improvement in reliability just to start thinking about this scheme. On a political level, I can't imagine that this ever gets more popular than underground storage.

[mfb]

No. Thousands of rocket launches show that.

Those thousands of launches haven't all been successful, though. And a failure with nuclear waste is rather more significant than a typical failure, even if we include minor things like failure to reach quite the target orbit.

A rocket failure does not imply a payload failure. If the rocket fails, the payload container can land back on Earth, and get shot to orbit with another rocket.

You need a rocket failure and a failure of the payload container at the same time for an accident. Something that never happened in the history of rocketry: No rocket launch with a launch escape system ever lost its payload. And even in this never-seen-before worst case of a worst case the radioactive material is probably localized and can be cleaned up (failure early on) or spread over vast amounts of ocean (failure at MaxQ or later).

The sheer mechanics of doing this should boggle the mind. The type of waste that is most dangerous is the heaviest and the most difficult to maintain safely, used fuel rods. They store used fuel rods in cooling tanks on site at the facilities or they use dry cask storage. And it take years to get it cool. To launch it into space you will have to shield it. The weight of what you have to launch would mean a heavy booster of some type. The material has been accumulating for years. You could consume all the engines we could build for some span of time. It would drive the costs of all launches up. Creating a cask that could survive a severe launch failure would increase the weight even more.

Could you please have a look at the numbers?
The waste would get many years to cool down, so continuous cooling is not necessary any more. The costs can be acceptable - including shielding and a container that survives launch failures.

More rocket launches will decrease launch costs because building more of the same makes unit costs go down. SpaceX would be happy to have a larger market, their launch capability will reach half the global launch market in something like a year and they need more customers.

It could also explode on the launch pad.

Launch abort system.

Sure, I get that safety measures exist. So far, this system has fulfilled its purpose once. It has failed once. That's not a reassuring success rate. We know that the rate of failure of these systems in practice tends to be much higher than in test conditions.

What has failed? No payload with launch escape system was ever lost in a rocket failure. The CRS-7 Dragon capsule survived. It hit the ocean hard because it was not foreseen to land safely in the event of a rocket failure, with a nuclear payload they would have let it land softly of course.

And don't forget the carbon dioxide produced by the rockets.

Completely negligible (and you can produce the fuel for them with electricity from nuclear power if you want - fully CO2-neutral).

Who says it's negligible? You are proposing this is how we handle all of our waste. And if we aren't going to use kerosene, that just pushes the cost even higher.

The calculations say that.
1 F9/Dragon launch involves burning ~500 tons of propellant. Some part of that is H2O, but let's say that is 500 tons of CO2 for a simple overestimate. It launches the waste of 1 year of a single 1 GW power plant. That is a CO2 emission of 0.05 g per kWh. Compare this to the numbers in this table: Hundreds of grams for coal, tens of grams for photovoltaics, about 10 grams for wind and nuclear power. Adding 0.05 grams is completely negligible.


@Zamfir: That container is extremely inefficient compared to the Dragon capsule, for example. It doesn't have to survive a free fall if it can deploy a parachute and then splash down in the ocean.
In my post on page 1 I assumed 5 tons/GWyear, which is close to the 50gwd/ton you used - without further concentration. The better efficiency of the container makes it possible, 5 tons to waste orbit for ~120 million dollars. That is something you can buy today, for a single launch. If you make a contract for 100 launches per year, expect significantly lower costs.
If we can get a factor 10 concentration of the waste relative to the 50 gwd/ton, the costs get tiny compared to other costs of nuclear power.

[Zamfir]

Sure, if you cut safety margins down to the standards of spaceflight, it becomes cheaper.

But why bother then? Underground storage is very affordable without such compromises. An alternative scheme should meet higher standards to be worth considering, not lower.

Edit: a technicality. Burn-up for nuclear plants is given relative to thermal power, not electric power. 50 gwd/ton is about 20 ton per year for a 1 GWe plant.

[mfb]

I trust a system that can land slowly more than a container designed to impact the ocean at high speed.

I prefer underground storages. But they are not without alternative.

Edit: a technicality. Burn-up for nuclear plants is given relative to thermal power, not electric power. 50 gwd/ton is about 20 ton per year for a 1 GWe plant.

Okay, then we need the concentration, but the factor 5 of reprocessing is sufficient.

[Bane Harper]

What if there is an accident to the mission carrying the waste? Imagine nuclear falling from our skies

[Eebster the Great]

What if there is an accident to the mission carrying the waste? Imagine nuclear falling from our skies

It is conventional to read a thread before posting in it.

[monkey3]

I wish we had an international waste disposal system or something like that , then we can sent it to the outer space instead of moon

[Himself]

The ocean trench idea is one to think about. Depending on the subduction zone and how deep we bury the waste, it may not even end up in the mantle, but would rather be scraped off the subducting plate along with the upper sedimentary layers and become part of the accretionary prism. In that case the waste would likely be buried under a few kilometers of metamorphic rock, though there is a chance it could be brought back up by faulting after a few million years. If it does go down with the plate, it might not be incorporated into the mantle, but rather continue down with the plate past the point of magma formation.