5 ms·
Could be. My unpopular prediction is that within 100 years, well-engineered deep-ocean burial will be considered good enough, given all else which is likely to
by a9h74j 5y ago
Could be. My unpopular prediction is that within 100 years, well-engineered deep-ocean burial will be considered good enough, given all else which is likely to become clear by then.
- poteznykrolik 5y agopraying irrationally for shipping the junk to the moon. that'll show em.
- artful-hacker 5y agoIf you can get it to the moon isn't it almost as easy to just shoot it into the Sun?
- whoisburbansky 5y agoActually nope. It takes more energy to slow yourself down enough to crash into the sun, starting from the earth, than it does to hop on over to the moon.
- tomjakubowski 5y agoDefinitely a stupid question, because I actually have no idea how they work: can a solar sail be "tacked" so as to decelerate towards the sun, like a sailboat sailing into the wind? (Setting aside the risky problem of getting this waste off earth and into space to begin with)
- hutzlibu 5y agoI have not done any calculations now, but given how small the solar wind is in drag, it would have to be a very, very big sail.
- blackboxlogic 5y agoTacking works because boats have a second "sail" interacting with a second fluid moving differently than the wind (the keel is in the water). There's no second thing to push against in space. If you "tack" your solar sail, you'll spin.
- chomp 5y agoIt's a misconception that shooting things to the Sun is easy, it's actually extremely difficult due to the fact that when you launch off of the Earth, after escaping Earth's gravity you're left with ~30km/s of leftover momentum that you have to do something with in order to not wind up in an orbit around the Sun.
- gregw134 5y agoWhy can't you just aim for a direct hit at 30km/s?
- NikolaeVarius 5y agoThe exact same reason why planets don't immediately fall into the sun
- Denvercoder9 5y agoThe momentum you inherit from Earth isn't in the direction of the sun, but roughly perpendicular to that direction. It's similar to a car going down the freeway at high speed that needs to make an immediate 90 degree right turn. It can't do that without slowing down first, if it did, it would slide sideways off the sideroad. It's harder in space because the car is going 30 km/s and there's no friction that slows you down.
- andyjohnson0 5y agoThat's not how orbital mechanics works. Objects move in elliptical orbits around the sun, not in straight lines. https://space.stackexchange.com/a/45619 https://space.stackexchange.com/a/45619
- djupblue 5y agoImagine sitting on a huge carousel spinning fast, like 100 times the speed of sound fast. Now imagine jumping off and trying to get to the center of it. Yes, gravity is holding us back from yeeting of into space but to get closer to the sun you need to slow down. A lot. It takes way less rocket fuel to speed up enough to leave the solar system than to get to the sun.
- comrh 5y agoI think it would be a pretty big difference in delta-v. https://upload.wikimedia.org/wikipedia/commons/9/93/Solar_system_delta_v_map.svg https://upload.wikimedia.org/wikipedia/commons/9/93/Solar_sy...
- deleted 5y ago[deleted]
- deleted 5y ago[deleted]
- arcticbull 5y agoThere's a few major issues with disposing of nuclear waste into the sun. First and foremost is that if the rocket explodes you'll contaminate a huge radius with dirty bomb like material. Probably not great. Further, if you do decide to launch it, it takes significantly more energy to shoot it out of the solar system than towards the sun. [1] [1] https://www.forbes.com/sites/startswithabang/2019/09/20/this-is-why-we-dont-shoot-earths-garbage-into-the-sun/?sh=1ed09af35d63 https://www.forbes.com/sites/startswithabang/2019/09/20/this...
- whoisburbansky 5y agoDid you mean to word that the other way around? It takes less energy to shoot it out of the solar system than towards the sun.
- arcticbull 5y agoOoof, good catch. Thank you, yes, that's what I intended to say. Too late to edit.
- adhesive_wombat 5y agoNo. Getting to the Sun requires scrubbing off nearly all the orbital speed of the Earth (30km/s), or the payload just orbits at a smaller radius. The delta v to the Moon is something like 7 times less than to the Sun (3 vs 20ish). The delta v need of the Parker Space Probe, which still "only" gets to 8.5 solar radii is so high it will use 7 Venus assists to get it close enough (it can't do big Jupiter assists because the solar panels it would need at Jupiter wouldn't be able to fit behind the sun shield at perihelion, and they didn't want to give it an RTG because they're saving plutonium for future missions). You can eventually hit the Sun with enough Venus assists and Earth assists, for a total delta v of under 4 km/s, but it'll take a very, very long time, and your nuclear waste will be doing Earth flybys until finally it hits the Sun. Also it might be tricky to get the ball of sun-melted radioactive slag to do accurate assists after the sun melts it on the last few close encounters.
- chasd00 5y agowhy not mars? didn't falcon heavy do that with a car?
- ch4s3 5y agoYeah, water is a very good radiation shield, and seafloor gunk doesn't hurt. The concrete casks probably sink pretty easily too.
- KarlKemp 5y agoAlso, salty seawater will eat through any metal at about the rate of a Windows 95 install process indicator. At that point, the nuclear gunk will disperse in the water, enter the food chain, and soon be part of your romantic lobster dinner. Enjoy!
- ch4s3 5y agoThe casks aren't metal on the outside, they're a specialized concrete. These casks have been dropped from building, exploded, struck by speeding trains, and burned at incredibly high temp all without losing integrity. Even still, uranium and similar waste products aren't water soluble and being more dense than any surrounding material so they would sink through the sediment and become locked in place. Here's a really old survey on the topic[1]. Here's another study [2]. Basically most of the waste would be short-lived beta and gamma emitters that are no longer dangerous after a few years. The longer lived alpha emitters aren't dangerous because alpha particles are easily stopped. You can safely hold a small amount of uranium in you hand. With respect to ocean life, there is also very little life in these trenches, and what life there is doesn't mix with food chains at higher levels. All of the food comes from biological material sinking, and nothing really goes the other direction. [1] https://www.iaea.org/sites/default/files/31404684750.pdf https://www.iaea.org/sites/default/files/31404684750.pdf [2] https://www.swr.de/-/id=13132940/property=download/nid=233454/12heab2/index.pdf https://www.swr.de/-/id=13132940/property=download/nid=23345...
- a9h74j 5y agoAlso, last time I estimated Bequerels (aka decays) in the ocean already, compared to what extremely dilute waste would add, well as I recall it was "a drop in the ocean." Need to recheck this sometime.
- PaulHoule 5y agoMost of the talk about deep-ocean burial has assumed that we're burying (worthless) fission products. Leftover uranium and plutonium in the fuel contains more than 95% of the energy from the original uranium so it is madness to bury it in a place we can't get it. I was thinking about writing a science fiction story about the Mormons and Scientologists fighting over Yucca Mountain 2000 years from now but now I don't think the Scientologists are going to last that long.
- a9h74j 5y agoYes, in terms of eventual ocean burial, as one option, I was assuming after reprocessing, burning in a fast breeder or Moltex, etc. This thought might be more for additional existence proof right now.
- PaulHoule 5y ago+1 for Moltex. I presented at the first thorium energy conference put on by Kirk Sorenson and it has been breathtaking to watch the focus shift away from thermal to fast and fluoride to chloride and now static fuels. Moltex really looks like the one and it will be wonderful if Canada develops a world-beating nuclear technology like what they attempted with CANDU.
- godelski 5y agoTo be fair, most people don't understand the storage problem. They think we have to store it for hundreds of thousands of years (ironically we don't think about this with plastics, heavy metals, or other products that don't decay). But it's storing for hundreds of thousands of years and assuming that the future civilizations don't know our language, we lost maps of these sites, and there's no reason to dig them up. This is left over cold war era thinking where WW3 brings us back to the stone age. But in reality it's fine to sit on the material, in place, and hope we figure out better things in the next few hundred years that we can safely do that. I've heard a complaint that this is passing the buck, like we did with climate, but I think that's only true if we assume no technological advancements. Or in other words, we stop researching. But also nuclear waste is a slowly building problem with a positive feedback loop so I think the comparison is bad anyways. In a few hundred years we'll probably pretty easily be able to extract the 95% of the energy that's left in our waste material and put it to good use. After all, France can already do a bit. It's just not cost effective for most because it's cheaper to mine than recycle.
- Manuel_D 5y agoYou don't need to predict anything. It's already been done: https://en.wikipedia.org/wiki/Ocean_disposal_of_radioactive_waste#History https://en.wikipedia.org/wiki/Ocean_disposal_of_radioactive_...