A bit tangential, but this week I discovered an interesting tidbit about nuclear waste.
We keep hearing that nuclear waste is an intractable problem, that the Yucca Mountain repository could never be approved, and there is no alternative, etc.
What I learned this week is that in the US (and worldwide) more waste was produced by weapons programs than by the civilian reactors. Roughly speaking the civilian reactors have produced about 120k tons of spent fuel in the US. Weapons programs created 100 million gallons of waste [1], which is in liquid form. I can't find the density, but I doubt is lower than that of water, and most likely it is much higher (Uranium is an extremely dense metal). In any case, at a minimum this is 380k tons, which dwarfs the waste from civilian sources.
All this waste was or will be stored at a facility similar to the one envisioned for Yucca Mountain, called WIPP (Waste Isolation Pilot Plant) [2], located in the desert in New Mexico. By a law passed by Congress, only waste from the weapons programs is eligible to be stored there, but there's no technological reason to not add civilian waste to the program.
WIPP is an underground long term storage facility in a massive salt mine. The video in link [2] is quite informative.
My personal conclusion is that nuclear waste disposal is a solved problem, both from the technological point of view and the political one.
[1] https://www.epa.gov/radtown/nuclear-weapons-production-waste
[2] https://www.wipp.energy.gov/