Microsoft Co-founder Bill Gates' advanced nuclear reactor company 'TerraPower' and billionaire Warren Buffett's power company 'PacifiCorp' announced plans to build a "next-generation" nuclear reactor in the US state of Wyoming. The "multi-billion dollar project" called 'Natrium' will be built on the site of an old coal plant. When active, the reactor will produce enough power for 4,00,000 homes.