Traveling wave reactor

TerraPower is another fourth-generation reactor design which would use the spent fuel from existing nuclear power plants. The idea is that a single reactor would have 60 years worth of fuel and so would never require refueling. Bill Gates and Nathan Myhrvold are investors, giving this company a relatively high profile among nuclear startups. One of the most important tools that today's nuclear companies have are supercomputers that can simulate how things work.