6 ms·

this might sound silly (and it probably is), but I don't understand why we don't build a hulking great cannon and shoot our nuclear waste into space.

Eric_WVGG 8y ago
because a misfire would result in a fine mist of nuclear fallout spread over the entire planet
- beaconstudios 8y ago
  hmm, I guess that's not ideal.
  - WalterBright 8y ago
    If it's spread out over the planet, the resulting radiation would be insignificant.
- pvaldes 8y ago
  We'll have to pack it very carefully in any case. Perhaps we should assume that this will happen and work with that scenery in mind. The concept of a fire resistant box is not new at a smaller scale; We can vitrify the less dangerous waste and store the crystal in steel containers. Then we could theoretically design explosion-proof containers for it with some outer sacrificial disposable layers made of a plastic clay-like matherial or so.
  - erikpukinskis 8y ago
    There’s some more weight.
    - pvaldes 8y ago
      Is much worse than that :-). The "space solution" can be split in three different possibilities. I will name the first "The slingshoot" We have succesfully used a "Slingshoot" approach to put heavy things up to 100t in the space many times. Hubble telescope (12t) or the orbiter from the space shuttle (100t) fall in this category. We could split our waste in chunks of 500Kg, pack it really well and just put it in an orbiter; the problem is that we can't go really far with this system (around 500 Km or so). We just will put the waste in a low orbit where things can fall again into the earth sonner or later. We had the Thiangong-1 case in 2018. Thus this "solution" after a few years would be the same as dumping the waste into the sea, but in a very expensive and creative way.
eseehausen 8y ago
Because we already know how to store it for thousands of years with minimal leakage without creating a contraption that could lead to nuclear waste raining down on our heads.
- pvaldes 8y ago
  To be fair, we already know how to store it with minimal leakage for thousands of years, but the tentation to just dump it in the Mediterranean (1980's), Somalia (1980-90's), seed it over Irak (Gulf's war) or leak it into the Japanese Sea (2011-17) is irresistible.
joe_the_user 8y ago
Oh, this reminds me of high school, when I asked a physicist my mother dating about the same idea. He worked for the Rand corporation and was overall pro-nuclear. Still, He considered for a second and did his best to explain... What I remember of his explanation was the point that if you launch a payload of material into space, you have essentially placed that payload in an elliptical orbital path, one that intersects earth's elliptical path. And since orbits are periodic, that payload is going to be intersecting earth's orbit regularly, meaning that in this instance, the chance of the material coming right back into the atmosphere is quite high.
BurningFrog 8y ago
I like to remind people that we already live on a radioactive planet. We can build nuclear reactors because radioactive stuff naturally is everywhere. There probably wouldn't be life here without it. So to me the "let's get it off the planet" idea is an overreaction. Radioactive material just need to be handled with common sense.
- jazzyjackson 8y ago
  Hmm... what's the over-under on dropping barrels into a volcano? You get a little radioactive steam surely...but eventually turns into radioactive dust... As an aside, ignorant physics question, does the half-life of something decrease with heat? Like does more beta-decay mean it gets to safe levels faster? Maybe a few years in between tectonic plates would do a planet good eh?
  - archgoon 8y ago
    > As an aside, ignorant physics question, does the half-life of something decrease with heat? Short answer: No. Definitely not in a Volcano. Long Answer: Decay rates are ultimately determined by the subatomic structure of the nucleus. This is why different chemicals, and different isotopes of said chemicals, will decay differently. A lone neutron will decay after about 15 minutes (which is a long time in subatomic scales), however, the two neutrons in (4/2)He will happily stick around forever. So melting a material won't have any impact on the structure of the nucleus, you're just disassociating the intramolecular bonds; same goes for turning said material into a gas. If you were to raise the temperature high enough, and we're talking sun-like (not the measly 5000k that you get on the surface, I mean like 27-million degrees you find in the core), then you'll actually start stripping and fusing nuclei, which will at that point change (but not necessarily decrease) the radioactive rates of whatever material you started with.
  - BurningFrog 8y ago
    The classic answer is to bury extremely long lived waste in a subduction zone at the bottom of the ocean, such as the Mariana Trench. A "subduction zone" is where two tectonic plates collide and fold into the depth of the planet. So anything you bury there would naturally travel deeper into the planet over the eons. I haven't heard any serious arguments against this, but I suspect it's impossible because people think it would "contaminate the oceans".
ben-schaaf 8y ago
I know others have addressed the dangers of this, but I had a little fun looking at the logistics. The UK alone produces 2Mt of radioactive waste[0] per year, ~9% is of "intermediate" level. Just sending those 18Mt into LEO would take 129,000 Saturn V launches per year. That's about one launch every 4 minutes. And LEO is not where we want to send anything. Lets assume a Trans-Lunar Injection is enough, bringing that number up to 370,000, almost one launch per minute. Just the RP-1 & LH2 fuel cost would be around $600,000 per launch[1], so about 222 billion USD per year (The fuel is the cheapest part of the launch). Each launch releases around 440,000 kg of CO2[2] into the atmosphere. That's 163Mt, an increase of 44% of the UK's current CO2 pollution from the launches alone. Just for fun, if we wanted to send all nuclear waste all the way to pluto using only Falcon Heavies we'd have to launch around 1.8 per second. Going off the 80 million USD price tag for these launches, that's 4.5 quadrillion USD. That's about 60 times the Gross World Product to cover the UK alone. [0] https://nda.blog.gov.uk/2017/04/03/how-much-radioactive-waste-is-there/ https://nda.blog.gov.uk/2017/04/03/how-much-radioactive-wast... [1] https://www.quora.com/How-much-fuel-does-it-take-to-travel-to-the-moon?redirected_qid=38695501 https://www.quora.com/How-much-fuel-does-it-take-to-travel-t... [2] https://space.stackexchange.com/questions/13082/calculate-falcon-9-co2-emissions https://space.stackexchange.com/questions/13082/calculate-fa...
- richardburden 8y ago
  2Mt is two metric tons, right? It surely is not 2 million metric tons. See the IAEA's estimates of total radwaste in storage or disposal worldwide: http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-waste-management.aspx http://www.world-nuclear.org/information-library/nuclear-fue... Because of the extremely high energy density of nuclear fuel, the amount of waste produced per Gigawatt-year of electricity generated is very small. A Saturn V has a payload of 140 Mt to low earth orbit. Total high-level waste is 22,000 cubic meters, possibly 220,000 Mt, assuming a density 10 times as great as water. 1,572 Saturn V launches would carry away all of that. All the high-level waste ever produced that has not been recycled. Most of it can be recycled in breeder reactors, so there is no need to carry it away!
  - 8y ago
ethbro 8y ago
Uranium (elemental) has a density of 19.1 g/cm^3. For comparison, lead has a density of 11.34 g/cm^3. It's heavy.
- ryacko 8y ago
  Yes, but how much coal versus uranium would a household use, if used to generate electricity in the most efficient way possible (cogeneration presumably)?
skywhopper 8y ago
One answer is that it probably isn’t possible to do what you say, but if it were the failure states are wildly unacceptable. Any “cannon” (or rail gun) capable of accelerating an object to escape velocity from the surface would likely burn the object up during its flight through the atmosphere, spreading its radioactive contents into the air to float around as low level global fallout for decades. But if instead you just launched it into space on a rocket... well what happens when a launch fails and the rocket blows up on the launch pad? If you’re lucky, you mark a few square miles as no-go zones and then move on to the next launch pad? Doesn’t strike me as a sustainable solution. One of my favorite ideas is to encase the waste into giant glass blocks, and build pyramids in the desert... but I doubt that’s very practical either.

Eric_WVGG 8y ago

because a misfire would result in a fine mist of nuclear fallout spread over the entire planet

beaconstudios 8y ago
hmm, I guess that's not ideal.
- WalterBright 8y ago
  If it's spread out over the planet, the resulting radiation would be insignificant.
pvaldes 8y ago
We'll have to pack it very carefully in any case. Perhaps we should assume that this will happen and work with that scenery in mind. The concept of a fire resistant box is not new at a smaller scale; We can vitrify the less dangerous waste and store the crystal in steel containers. Then we could theoretically design explosion-proof containers for it with some outer sacrificial disposable layers made of a plastic clay-like matherial or so.
- erikpukinskis 8y ago
  There’s some more weight.
  - pvaldes 8y ago
    Is much worse than that :-). The "space solution" can be split in three different possibilities. I will name the first "The slingshoot" We have succesfully used a "Slingshoot" approach to put heavy things up to 100t in the space many times. Hubble telescope (12t) or the orbiter from the space shuttle (100t) fall in this category. We could split our waste in chunks of 500Kg, pack it really well and just put it in an orbiter; the problem is that we can't go really far with this system (around 500 Km or so). We just will put the waste in a low orbit where things can fall again into the earth sonner or later. We had the Thiangong-1 case in 2018. Thus this "solution" after a few years would be the same as dumping the waste into the sea, but in a very expensive and creative way.

eseehausen 8y ago

Because we already know how to store it for thousands of years with minimal leakage without creating a contraption that could lead to nuclear waste raining down on our heads.

pvaldes 8y ago
To be fair, we already know how to store it with minimal leakage for thousands of years, but the tentation to just dump it in the Mediterranean (1980's), Somalia (1980-90's), seed it over Irak (Gulf's war) or leak it into the Japanese Sea (2011-17) is irresistible.

joe_the_user 8y ago

Oh, this reminds me of high school, when I asked a physicist my mother dating about the same idea. He worked for the Rand corporation and was overall pro-nuclear. Still, He considered for a second and did his best to explain... What I remember of his explanation was the point that if you launch a payload of material into space, you have essentially placed that payload in an elliptical orbital path, one that intersects earth's elliptical path. And since orbits are periodic, that payload is going to be intersecting earth's orbit regularly, meaning that in this instance, the chance of the material coming right back into the atmosphere is quite high.

BurningFrog 8y ago

I like to remind people that we already live on a radioactive planet. We can build nuclear reactors because radioactive stuff naturally is everywhere. There probably wouldn't be life here without it. So to me the "let's get it off the planet" idea is an overreaction. Radioactive material just need to be handled with common sense.

jazzyjackson 8y ago
Hmm... what's the over-under on dropping barrels into a volcano? You get a little radioactive steam surely...but eventually turns into radioactive dust... As an aside, ignorant physics question, does the half-life of something decrease with heat? Like does more beta-decay mean it gets to safe levels faster? Maybe a few years in between tectonic plates would do a planet good eh?
- archgoon 8y ago
  > As an aside, ignorant physics question, does the half-life of something decrease with heat? Short answer: No. Definitely not in a Volcano. Long Answer: Decay rates are ultimately determined by the subatomic structure of the nucleus. This is why different chemicals, and different isotopes of said chemicals, will decay differently. A lone neutron will decay after about 15 minutes (which is a long time in subatomic scales), however, the two neutrons in (4/2)He will happily stick around forever. So melting a material won't have any impact on the structure of the nucleus, you're just disassociating the intramolecular bonds; same goes for turning said material into a gas. If you were to raise the temperature high enough, and we're talking sun-like (not the measly 5000k that you get on the surface, I mean like 27-million degrees you find in the core), then you'll actually start stripping and fusing nuclei, which will at that point change (but not necessarily decrease) the radioactive rates of whatever material you started with.
- BurningFrog 8y ago
  The classic answer is to bury extremely long lived waste in a subduction zone at the bottom of the ocean, such as the Mariana Trench. A "subduction zone" is where two tectonic plates collide and fold into the depth of the planet. So anything you bury there would naturally travel deeper into the planet over the eons. I haven't heard any serious arguments against this, but I suspect it's impossible because people think it would "contaminate the oceans".

ben-schaaf 8y ago

I know others have addressed the dangers of this, but I had a little fun looking at the logistics. The UK alone produces 2Mt of radioactive waste[0] per year, ~9% is of "intermediate" level. Just sending those 18Mt into LEO would take 129,000 Saturn V launches per year. That's about one launch every 4 minutes. And LEO is not where we want to send anything. Lets assume a Trans-Lunar Injection is enough, bringing that number up to 370,000, almost one launch per minute. Just the RP-1 & LH2 fuel cost would be around $600,000 per launch[1], so about 222 billion USD per year (The fuel is the cheapest part of the launch). Each launch releases around 440,000 kg of CO2[2] into the atmosphere. That's 163Mt, an increase of 44% of the UK's current CO2 pollution from the launches alone. Just for fun, if we wanted to send all nuclear waste all the way to pluto using only Falcon Heavies we'd have to launch around 1.8 per second. Going off the 80 million USD price tag for these launches, that's 4.5 quadrillion USD. That's about 60 times the Gross World Product to cover the UK alone. [0] https://nda.blog.gov.uk/2017/04/03/how-much-radioactive-waste-is-there/ https://nda.blog.gov.uk/2017/04/03/how-much-radioactive-wast... [1] https://www.quora.com/How-much-fuel-does-it-take-to-travel-to-the-moon?redirected_qid=38695501 https://www.quora.com/How-much-fuel-does-it-take-to-travel-t... [2] https://space.stackexchange.com/questions/13082/calculate-falcon-9-co2-emissions https://space.stackexchange.com/questions/13082/calculate-fa...

richardburden 8y ago
2Mt is two metric tons, right? It surely is not 2 million metric tons. See the IAEA's estimates of total radwaste in storage or disposal worldwide: http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-waste-management.aspx http://www.world-nuclear.org/information-library/nuclear-fue... Because of the extremely high energy density of nuclear fuel, the amount of waste produced per Gigawatt-year of electricity generated is very small. A Saturn V has a payload of 140 Mt to low earth orbit. Total high-level waste is 22,000 cubic meters, possibly 220,000 Mt, assuming a density 10 times as great as water. 1,572 Saturn V launches would carry away all of that. All the high-level waste ever produced that has not been recycled. Most of it can be recycled in breeder reactors, so there is no need to carry it away!
- 8y ago

ethbro 8y ago

Uranium (elemental) has a density of 19.1 g/cm^3. For comparison, lead has a density of 11.34 g/cm^3. It's heavy.

ryacko 8y ago
Yes, but how much coal versus uranium would a household use, if used to generate electricity in the most efficient way possible (cogeneration presumably)?

skywhopper 8y ago

One answer is that it probably isn’t possible to do what you say, but if it were the failure states are wildly unacceptable. Any “cannon” (or rail gun) capable of accelerating an object to escape velocity from the surface would likely burn the object up during its flight through the atmosphere, spreading its radioactive contents into the air to float around as low level global fallout for decades. But if instead you just launched it into space on a rocket... well what happens when a launch fails and the rocket blows up on the launch pad? If you’re lucky, you mark a few square miles as no-go zones and then move on to the next launch pad? Doesn’t strike me as a sustainable solution. One of my favorite ideas is to encase the waste into giant glass blocks, and build pyramids in the desert... but I doubt that’s very practical either.