If we're looking out for civilisations descended from ours then there's likely no need for this because they will likely be able to deal with it, or might even find it a valuable resource of elements.
Someone else knows better here, but I think a lot of the waste exists because we don't burn it all in nuclear reactors - in which case why not make reactors that can burn it rather than leave it as waste.
The reason most nuclear operating countries don't run partition and transmute their waste into faster-decaying, less radiotoxic material is that it is a very expensive remote chemical process that has been historically met with deafening activist/public opposition. Much easier and cheaper to just mine barely radioactive uranium, enrich it, fabricate it, and do once through. If/when uranium prices reach roughly $360/kg, then the overall economics of recycling and breeding may start to make more sense.
Something I just realized I don’t know—are there no radioactive waste materials from using recycled materials?
It makes sense to a degree that if the usage is circular, problem solved. But am I wrong? Is it theoretically or actually possible to achieve 100% “reclamation”?
There are lots of radioactive waste materials when using nuclear recycling. Basically, all recycling allows you to do is to split ~90% of the uranium atoms into fission products rather than the more typical 5% that we do in our current fleet. The leftover fission products are still radioactive, but they decay a bit faster than the material in non-recycled spent fuel (actinides like Np, Pu, Am, Cm).
While there may be less total solid waste per kWh when you recycle, you do add the complexity of having lots of more diluted liquified radioactive waste streams from the processing. Liquified waste management has proved challenging from our weapons programs, e.g. at Hanford, though it could certainly be handled better than that.
likely no need for this because they will likely be able to deal with it
That kinda assumes that technology always progresses forward and there are no regressions and dark ages. 10k years is a long time. The Great Pyramid of Giza was built roughly 5k years ago, so we are aiming here for twice that long. During that time many empires have risen and fallen. That is a lot of time for technical things to go forgotten.
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If we're looking out for civilisations descended from ours then there's likely no need for this because they will likely be able to deal with it, or might even find it a valuable resource of elements.
Someone else knows better here, but I think a lot of the waste exists because we don't burn it all in nuclear reactors - in which case why not make reactors that can burn it rather than leave it as waste.
The reason most nuclear operating countries don't run partition and transmute their waste into faster-decaying, less radiotoxic material is that it is a very expensive remote chemical process that has been historically met with deafening activist/public opposition. Much easier and cheaper to just mine barely radioactive uranium, enrich it, fabricate it, and do once through. If/when uranium prices reach roughly $360/kg, then the overall economics of recycling and breeding may start to make more sense.
Something I just realized I don’t know—are there no radioactive waste materials from using recycled materials?
It makes sense to a degree that if the usage is circular, problem solved. But am I wrong? Is it theoretically or actually possible to achieve 100% “reclamation”?
There are lots of radioactive waste materials when using nuclear recycling. Basically, all recycling allows you to do is to split ~90% of the uranium atoms into fission products rather than the more typical 5% that we do in our current fleet. The leftover fission products are still radioactive, but they decay a bit faster than the material in non-recycled spent fuel (actinides like Np, Pu, Am, Cm).
While there may be less total solid waste per kWh when you recycle, you do add the complexity of having lots of more diluted liquified radioactive waste streams from the processing. Liquified waste management has proved challenging from our weapons programs, e.g. at Hanford, though it could certainly be handled better than that.
I wrote up a small primer on nuclear recycling with more details here: https://whatisnuclear.com/recycling.html
That kinda assumes that technology always progresses forward and there are no regressions and dark ages. 10k years is a long time. The Great Pyramid of Giza was built roughly 5k years ago, so we are aiming here for twice that long. During that time many empires have risen and fallen. That is a lot of time for technical things to go forgotten.
The point is to look out for human or similar beings who have somehow lost access to our knowledge, including the ability to read our languages.
The entire thing is an exercise in hyper-transgenerational communication (if I might turn a phrase).