Japan has 63 nuclear-powered energy plants, with plans to construct or order almost a dozen more. Almost 35% of Japan's energy comes from nuclear power. The main benefit of nuclear power is it produces energy at a lower operating cost than other sources, and it doesn't contribute to global warming. The disadvantage of nuclear power is that there is no good solution to the problem of storing radioactive nuclear waste, and that a major earthquake in Japan could cause a dangerous accident.