The importance of the "several centuries" is that it sets an upper limit on how long we can wait before reprocessing or burying (or otherwise permanently dispos

The importance of the "several centuries" is that it sets an upper limit on how long we can wait before reprocessing or burying (or otherwise permanently disposing of) spent nuclear fuel. After that point, the fuel's gamma activity will have declined so much it is no longer self-protecting from "amateur" reprocessing and diversion of the plutonium. I think it's quite plausible that today's dry casks could last several centuries. So, we have a technology that will last as long as it could be intended to. Arguably it's better for our descendants to do this and let them deal with the waste, not needlessly do something much more expensive. Our descendants will not like that we squandered wealth and left them with larger debts or lower growth either. Always consider what else could be done with resources when you advocate their use.