If the output of waste from a nuclear reactor is still that 'hot', they're doing it wrong. That waste then needs reprocessed for draining more energy out of it,

If the output of waste from a nuclear reactor is still that 'hot', they're doing it wrong. That waste then needs reprocessed for draining more energy out of it, furthering the transmutation to good 'ol lead. It'd be akin to burning gasoline with a 100% conversion output of CO. Guess what: that's incomplete combustion and you just lost a lot of energy. But that's what these reactors do all the time. If you can't get lead out of it, at least get something that only has a half-life of a few billion years. Then its about as dangerous as lead.