b'C HAPTER T HREET H E U RA N I U M T RA I L L EA DS T O I D A H OUranium: a heavy, slightly radioactive metallic element.Encyclopedia BritannicaA Uranium is dispersed widely over the Such a mine was discovered in Zaireearth; the soil in the average backyard (formerly, the Belgian Congo) about therchaeologists has 2.7 parts per million. It is more time that the world was learning thatexcavated the Imperial Roman Villa common than tin. But backyard concen- radium might have wonderful curativenear Naples in 1910. In a first-century trations are hardly worth mining. A properties. Because of its richly concen-A.D. mosaic mural, they found pale good uranium mine might have 30,000 trated ore, the Shinkolobwe mine pro-yellow-green glass containing one per- parts of uranium per million, but a duced uranium far more cheaply thancent uranium. Roman artisans probably bonanza-class uranium mine would anywhere else. Other uranium minesused a uranium-bearing mineral inten- have 100,000 parts closed, and the Shinkolobwe satisfiedtionally to obtain the color. The tech- per millionten most world demand until well afternique may then have been lost. 1 percent of the World War II. 2ore.Uranium, when it was discovered as an The discovery of radioactivity was aelement and named in 1789, had no prelude to other discoveries that led to aknown use. Someone eventually new twentieth century mar-learnedagainthat it produced a ket for uranium. First, thepleasant orange or yellow glaze world learned that atomson ceramic goods. definitely are not thePhotographers used it to smallest particles oftint photographs. For matterrather,such aesthetic uses, the atoms are built ofworld required only a INEEL 99-320-1-8 electrons, protons, and neu-few hundred tons of ore trons, with most of the weight in thea year. Mines in protons and neutrons.Bohemia, Portugal, andColorado supplied the Next, uranium, like most elements, hasmodest demand. Then more than one isotope. Some atomsHenri Becquerel discovered its The Homer Laughlin Company, maker of Fiesta contain more neutrons than others andproperty of radioactivity. In 1898 Marie Ware, used uranium to obtain the bright orange weigh slightly more. Uranium-235Curie, investigating further, discovered glaze known as Fiesta Red. In 1943, the company weighs less than uranium-238, forradium in uranium ore and began to obtained a license from the Manhattan District and example, and more than uranium-233.elucidate its decay products. Everything used depleted uranium until 1972. Although different isotopes act andchanged. react the same way when combining1 8'