-3-, 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’. 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 industry will become the principal source of this material within the next two decades. In today's commercial reactors plutonium is produced as a by-product in the production of electricity. As a result of the growth of the nuclear power industry, the ‘AEC estimates that the total cumulative production of plutonium in the commercial sector of the United States will be some 4.5 million kilograms by the year 20002. Since plutonium, likeuranium, can serve as a reactor fuel, both > are recovered from spent reactor fuel in anticipation that ‘ they will be recycled. The reactor together with the variety _—— 2/ The ratio of the concentrations of plutonium-239 to uranium in ores varies from 4xl0713 to 1.5xio711l. Katz, J.J., Chapter VI, The Chemistry of Actnide Elements, Methuen and Co., Ltd., London, 1957, pp. 239-330. 3/ Environmental Statement, Liquid Metal Fast Breeder Reactor Demonstration Plant, USAEC, WASH-1509, April 1972, p. 149.