Wy II, Plutonium Use and Public Health Plutonium occurs in nature, : although in such small amounts that it does not constitute a practical source of the element 2 . . ‘ Plutonium is bred in nuclear reactors by the . capture of neutrons in uranium-238. To date, the nuclear Weapons program has been the principal source of plutonium. However, it is anticipated that the commercial nuclear power inéustry will become the principal source of this material within the next two decades. In today's commercial reactors plutonium is sroduced as a by-product in the production of elez<ricity. As @ result of the growth of the nuclear power industry, the AEC estimates that the totai cumulative production of plutonium in the commercial sector of the United States will ‘be some 4.5 million kilograms by the year 20007. Since plntonium, lixe uranium, can serve as a reactor fuel, both are recovered From ssent reactor fuel in anticipation that they will be recvcled. The reactor together witn the variety 2/ Tne ratio of the concentrations of plutonium-239 to “ranium in cres varies from 4xl0713 to 1.5x10711. Katz, J.J., Cnasies Vi, The Chemistry of Actinide Elements, Methuen and Co., 2/ Leé., Loncon, 1957, pp. Environmental Statement, 239-330. Liauid Metal Fast Breeder Reactor Terenscracion Plant, USAEC, WASH-1509, April 1972, p. 149.