Bill Gates is just one of the perhaps-surprising public figures who is bullish on nuclear energy as a future power source. In fact, he is so supportive of one new type of nuke called TWR (traveling-wave reactor) that he is the major investor behind Terra Power, which is using Microsoft’s computing power to build next-generation power plants, possibly in conjunction with China. TWR can burn depleted uranium (instead of enriched) and other lower-quality radioactive fuels for much longer periods of time — possibly up to 100 years. “The idea is to be very low cost, very safe and generate very little waste,” Gates says in an Associated Press article.