There are radionuclides in those casks with half-lives of 200,000 years - much longer than human civilisation, and much longer still than the lifetime of a human writing system. We don't even know how to make a label that will make sense in 200,000 years.

This attitude only makes sense if one's view is that humanity isn't going to last more than 10,000 years.

Unless we can find a way of rendering nuclear waste safe, then we have to find a way of making it so inaccessible that a future civilisation is unlikely to come across it by accident, and so secure that even a major earthquake won't cause it to leak into the environment.

Storing this stuff in metal tins on the surface isn't even a gesture at a solution.

No, the attitude makes sense because of the time value of money.

At any point, if interest rates aren't pretty much exactly zero, it pays to delay burying waste. The present cost of guarding it at the surface is < the cost of burying it now. If, at any time, the interest rates do drop to zero and stay there, it can be buried then.

The only real argument against this is that the waste ceases to be self-protecting from "amateur" diversion of plutonium in about 300 years, which could greatly increase the cost of guarding. But that's no justification for burying it now.

Waiting also reduces the thermal output from fission products, which reduces heat buildup in the repository, at least a bit. And it would allow the waste to be reprocessed (and more easily) if that (perhaps unexpectedly) becomes appropriate. It would also allow time for other disposal methods, such as launching into space, to become competitive. How cheap will the descendants of SpaceX's launchers be in 300 years?

I think there may have been an argument for rapidly burying waste during the cold war, where surface waste could be volatilized by a direct H bomb strike, causing enhanced local long term fallout. That's more an argument against nuclear power itself, though, as NPPs could also be disrupted by direct strikes.

> "amateur" diversion

This is always a funny topic when people wax philosophical about dirty bombs as though you wouldn't get cooked trying to open a cask.

I sort of mostly agree. Long term deep storage is nice because with a good design, we can pretty much set and forget. Most LLFPs aren't actually very dangerous as they don't emit gamma rays, but Tc-99 and I-129 are pretty nasty stuff. we could probably reprocess those into Ru and throw the rest of it into a deep geologically stable hole. Any society in 10k years that could find the stuff will be advanced enough to avoid or rebury it. As long as we don't store anything highly bioavailable near water, it should be fine. By 10k years from now the amount of radiation actually being released will be miniscule. But, I'm all for a big deep hole.