Uranium mining in the United States 1954 in the Sierra Nevada of Kern County, along the Kern River about northeast of Bakersfield. Two mines, the Kergon mine and the Miracle mine, made small shipments in 1954 and 1955. Uranium occurs as uraninite and autunite in shear zones in granodiorite. Accessory minerals include fluorite and the molybdenum minerals ilsemanite and jordisite. The first uranium identified in the US was pitchblende from the Wood gold mine at Central City, Colorado in 1871. Uranium mining in southwest Colorado goes back to 1898. The Uravan district of Colorado and Utah supplied about half the world's radium from 1910 to 1922,
Fission products (by element) Fission products (by element) On this page, a discussion of each of the main elements in the fission product mixture from the nuclear fission of an actinide such as uranium or plutonium is set out by element. Se-79, half-life of 327k years, is one of the long-lived fission products. Krypton-85, half-life 10.76 years, is formed by the fission process with a fission yield of about 0.3%. Only 20% of the fission products of mass 85 become Kr itself; the rest passes through a short-lived nuclear isomer and then to stable Rb. If irradiated reactor fuel is reprocessed, this radioactive krypton