Nuclear guy here. Burning old plant's waste is extraordinarily expensive and we need to reduce nuclear costs overall, so I don't think waste burning is a good option at the moment. There is scientific consensus that deep geologic repositories like the one under construction at Onkalo in Finland are the solution for nuclear waste. Let's establish long-term disposal like this to put the concern to bed and then worry about breeding and reprocessing if and when it becomes necessary in 60+ years. There is no shortage of nuclear fuel in sight.