Uraninite named, was either unknown, impossible or not economically feasible). The mineral has been known at least since the 15th century from silver mines in the Ore Mountains, on the German/Czech border. The type locality is the historic mining and spa town known as Joachimsthal, the modern day Jáchymov, on the Czech side of the mountains, where F. E. Brückmann described the mineral in 1772. Pitchblende from the Johanngeorgenstadt deposit in Germany was used by M. Klaproth in 1789 to discover the element uranium. All uraninite minerals contain a small amount of radium as a radioactive decay product of uranium. Marie
Peak uranium amount of energy to be produced per mass unit of uranium, because U-238, which constitute 99.3% of natural uranium, is not used in conventional reactors which instead use U-235 which only represent 0.7% of natural uranium. In 1983, physicist Bernard Cohen proposed that the world supply of uranium is effectively inexhaustible, and could therefore be considered a form of renewable energy. He claims that fast breeder reactors, fueled by naturally-replenished uranium-238 extracted from seawater, could supply energy at least as long as the sun's expected remaining lifespan of five billion years., making them as sustainable in fuel availability terms as