Random Person wrote:Anyway, the sun is a terrible option. Use the moon instead, much less energy to get there. Added bonus of it being just a rock instead of eventually radiating it all back to us.
Dig a hole and dump it in is still the best option though.
Lucky us, 1999 has already passed.
Iskander wrote:... You could convert it into a more stable form. The French currently reprocess and vitrify, for instance.
Yeah, part of that reprocessed fuel passes through my country on its way to our nuclear plants... by train.
Fotiadis_110 wrote:Edit: Actually I have a longer term solution... you remember the Lagrange points?
Stable orbit locations away from the planet with little likelihood of disruption :p
I'd still feel safer with them in the sun, while the moon is somewhat more likely to be colonised.
There's only two really long-term "stable" Lagrange points: L4 and L5. I don't know if you follow space news, but the astro-scientific community is fond of Lagrange spots too for obvious reasons. They put deep-space observation platforms there for those kinds of research by which an Earth orbit is disruptive for the instruments sensitivity, or to have permanent shadow or something. Sofar, L4 and L5 of the Earth-Moon system are not in use, but they're kind of obvious spots for industrial stations (if those ever get off the ground).
You could probably just impact the waste into the moon if you wanted. It takes much less energy to do that than to put something on a trajectory towards the Sun, trust me. Orbital mechanics.
Let's see...for Earth, mu is 398600 km^3/s^2, for the Moon it's 4917, and for the Sun it's 132712440018. The Moon orbits at a mean radius of 384000 km from the Earth. Let's say you start out in LEO, in a 200-km altitude circular orbit - it's basically sufficient to make a burn to expand your orbit into a highly eccentric elliptical one that takes you into the neighborhood of the Moon at apogee. It's not very hard to aim, actually - the Moon has gravity and will capture you if you time the burn right. So - your initial radius is 6578 km, with e = 0. You want to go into a 200 km by 384000 km orbit. You end up with e = 0.998 - the semi-major axis is 192100 km. This means you have a specific orbital energy of -1.037 km^2/s^2 - by comparison, if you're in LEO, your specific orbital energy is in the neighborhood of -30 km^3/s^2. This trajectory will see you crashing into the Moon. Now, how much delta-V do you need? Well - assuming it's an impulsive burn (finite burn is a pain in the ass) you need about 3.2 km/s. The Apollo TLIs required about that much.
Now, escaping outright from the Earth's gravity and then deorbiting an object into the Sun? Well, let's see here...once you've left the Earth's SOI (we're using patched conics here) you need to end up with a periapsis inside the Sun, let's say. That's 6.955*10^8 - let's say 6*10^8 will do. The Earth is 1 AU out - 1.44*10^11. So, your e = 0.9917. This makes your semi-major axis 7.225*10^10 m - about half an AU. That makes your SOI -0.92 km^2/s^2. At your apoapsis, you need to have a velocity of more or less 0 km/s to the Sun. But the Earth is traveling 30 km/s relative to the Sun on average. So, you need to make a burn that'll have you traveling 30 km/s relative to the Earth as you get far away from it. Now, this takes a lot of energy. Neglecting a lot of stuff (i.e. velocity components and so on - this is very simplified) you'll need to make about a 24 km/s burn from LEO to do that. It'll actually be more, I think.
Now, tell me - is it easier to get into LEO and then make a 3.2 km/s burn or a 24 km/s burn?
I don't have to ELIMINATE all the 30km/s once in orbit.
You can just shoot backwards and the velocity required to penetrate the earths gravitational field will be deducted with relation to the sun in the first place thus imparting a different kinetic energy in the first place.
You still have to break the gravitational grip, but that isn't all that hard.
Additionally a nice curving spiral decay orbit doesn't even require that we remove more than 1 km/h according to my understanding.
personally I would rather have a nice spiral that would miss the earth when we return next year, but that is because planets are not point objects in space, although they are somewhat similar.
One sensible point is that a sun launch system could benefit from the use of a rail-gun launch system... and you could use it every single day for quite a few hours to achieve your desired path. (I believe there would be a 3-4 hour opening, only 1/6th of a day.)
The moon also offers a daily target, however it is a very small sweet spot in the sky requiring rocketry and manoeuvring thrusters to ensure a decent hit.
Not to mention 1000 years ago we were starving, and believed god was everything we needed to live and survive.
These days we normally use medicine and hope god will help us get through the day.
In 1000 years I do not want my descendants complaining about the radioactive chunks we threw at the moon in the hope it would be rid of them eternally.
Also: L4 and L5 look great right?
Except they are 'peaks' in the gravitational system, any movement away from your desired point will lead to destabilising their positioning.
Manoeuvring thrusters will be required, Batteries not included.
No, you do have to do that. Orbital mechanics is pretty strict. Again, based on the patched-conic approximation (which is a good approximation) you need a lot of delta-V to end up in the Sun. Again, if you look at the sort of trajectory that an object headed into the sun would travel (a very eccentric elliptical one) you can figure out the required velocity at the apses.
The calculations I made were based on going backwards in the first place - the Earth travels about 30 km/s relative to the Sun, so you need to, one way or another, get rid of most of that 30 km/s tro end up plunging into the sun. Escaping from the Earth so that you're on a retrograde trajectory (that is, the Earth appears to end up outrunning you) is the cheapest way to do it.
I'm not so sure about the low-thrust trajectories, but 1 km/s is waaaay too low. It also takes a long time and you need pretty good electric thrusters to do it.
Bottom line: orbital mechanics does not work that way!
... the ultimite goal is to shift the oribital path of your radioactive to a trajectory that isn't going to hit the earth nor the moon, using the least energy required.
If we slow the projectiles enough, could they not enter near circular orbits and simply orbit as the glowing ring of rocks between earth and Venus? It would be a rather spectacular way to mark the existence of our species for future sentient's to find,
The fact they are made of radioactive waste might indicate the manner by which our society was destroyed, and help explain the whole issue of why a certain layer of rocks hold an unusually large quantity of radioactive isotopes :p
And if it becomes profitable to harness the waste we cannot use now, they are just a radioactive toss away from the planet in the first place :p
footsie: long term storage is quite viable on the planet, as long as we keep the amount down, fourth gen reactors will do just that, my guess is that further reprocessing will find use for THAT "waste" as well.
the problem really is reprocessing and the legality of it(oh noes nuclear proliferation!) where you get pure materials of different kinds, you just need to find a USE for it.
The basic problem with radioactive decay is it is never as easy or simple as we desire.
For instance, Alpha decay, which turns large elements into smaller ones, is common, and can hit ANY of the other atoms in the reaction mixture, including those which transmuted into Lead.
Lead is very stable as a molecule, thus tending itself to be the final product of many radioactive decay paths, however when hit by a Alpha particle it becomes something else and is once again radioactive.
Such radioactivity can have VERY long half-lives, and thus undesirable from many angles, particually if they decay into something which emits dangerous beta or similar radiation.
As a side note alpha radiation typically causes skin burns and little more due to it's inability to penetrate so technically it isn't all that dangerous (at least in low amounts, you can get anything from first to third degree burns, just like from touching something hot)... but if you eat it, it will burn your insides quite happily but most things stay in your digestive tract (also beware radioactive dust in your lungs). Then again if it's something your body utilises like calcium undergoing alpha decay, then it will burn EVERYTHING WHERE-EVER IT GOES, from your bloodstream to your brain!
These are reasons why 're-using' 'stable' radioactive waste is never as people friendly as using non-radioactive sources in the first place :p
footsie: hey, i am no nuclear scientist, but i know you can(with varying amount of work) separate the materials into(relatively) pure piles, at which points as far as i can see it, you got resources not waste, the question is just resources for WHAT exactly?
I'm no Nuclear scientist, however I have been taught enough about nuclear physics to understand that there are differing forms of radiation, and some of them are made up of subatomic particles, and high energy subatomic particles (which ARE what this kind of radiation is) can be used to bombard other molecules and say make gold from platinum, turn Oxygen into a radioactive path that decays into Carbon 14 (which later decays into Nitrogen), and other elemental defying book changing effects.
And as for 'purifying' substances.
Some splits are easy, say removing Calcium from limestone by removing the carbonate.
Some splits are HARD particularly separating metals, such as gold from silver, or the reverse.
The biggest commonality is that ALL OF THEM require more resources to preform than you are left with at the end, the remainder turns into waste which must be disposed of.
Only occasionally is the remaining waste capable of being put back in at the start of the process and thus the 'waste' can be reprocessed 'to exhaustion' (which means that the continued waste production goes back in time and again, the waste remaining of which is also added and it cycles through to infinity (in theory) till all the waste no longer exists as the waste stream stops increasing in size, hereby they can claim it is being 'consumed'), often the process of separating metals of very similar properties is so difficult, it isn't even bothered.
Another point to make is Carbon Steel. Everyone knows Iron is an element, used to make Steel. The thing is that the method used to produce Iron from Iron sand or Iron ore utilises great amounts of carbon.
This carbon is almost impossible to remove from the final product, and typically this is not an issue as the carbon trapped within can be manipulated various ways (through forging processes and such) to change the structure and state of the iron, which of course changes the PROPERTIES of the iron, including things like spring steel and ultra-hard Steel which is vulnerable to shattering (apparently the Katana was a low carbon outer blade wrapped around a soft iron (high carbon) core to provide it with strength and shock absorption, I've since read differently, specifically every katana was the product of it's maker, with varying designs and methods), these varying properties are normal and harnessed by various designers and engineers for various tasks.
And a final point: People want to make a buck from whatever they can, and I do mean ANYTHING, including human corpses if they can, so what is to stop people taking 'not approved to be used around people' materials from your splitting process (due to latent radioactivity risks) and say, making baby prams out of it?
Laws?
Can you really find a way to test EVERYTHING that enters the consumer production chain, even when people don't want you to discover the issue?
The easiest way to to prevention is to remove the temptation by simply never giving them the opportunity.
The most reliable way to prevent murder is to prevent anyone from being born, but such paranoid actions aren't justified by the result (a.k.a. better to have murder forever).
At the end of the day, we're constantly being exposed to radiation, there just isn't a lot of it. 'Non-radioactives' are mostly harmless (though I certainly don't agree with using 'contaminated nickle' for silverware! reasonable amounts in coins would be fine, though), and by paying attention to what's going to be in proximity with the radioactives, you can control the types of non-direct wastes that you have to deal with. Furthermore, both the direct wastes & the indirect wastes are going to be inherently restricted in amount, because for the most part nothing comes into direct contact with radioactives (certainly the amount of reprocessing equipment should be small enough that it can be disposed of in companion vaults, if the material isn't itself valuable enough to process).
And for your final point: how much contaminated material do you think there is? This is NOT a primary source for almost anything, I'm not even confidant that you can build a skyscraper out of all this stuff (I assume that you can, but skyscrapers use quite a lot of material...), there's just not very much of it. Further, all of this material traces back to a few already regulated locations. Tracking & controlling this stuff isn't all that hard, the worst that you'll get is likely in the medical field & smoke-detectors, neither of which is likely to have large exposures for the indirect wastes in question. Quite honestly, old already-existing stockpiles of nuclear materials from the Soviet Union are more problematic than anything that became dangerous because of transmutation, because not all of those are confidently under control yet (some have apparently even been robbed). At the end of the day, the particular opportunity that you're telling us to worry about isn't a realistic opportunity, AND things that have ALREADY happened pose more of a risk than that.
If you're worried about keeping track of radioactive substances and similar items, it's actually fairly simple - they very politely announce their presence to all and sundry. Why? Well - they're radioactive, and modern instruments are damn sensitive. Who knows - maybe you could tag certain objects with low-level sources to make finding them easier if it became necessary.
Hm - speaking of which, perhaps I should get one of those self-luminous tritium keychains.
