Oe se en RN OREO Vhen plutonium was regarded ag amllitary substance and was accordingly given little public attention. Now it is much publicized as the energy source of the not too distant future. Apri? “(70 was a time of irangition, and I felt the strong presence of the N earlier tradition, and the decision to speak was not an easy one for me. I have t.ad no regrets. . Piuionium and Public Health For the sake of completeness let me give. you some background on plutonium. itis an element that is virtually non-existent in the earth's natural crust. In the early 1940's it was first produced and isolated by Atomic Energy Commission. sheeted Dr. Sertborg and colleagues; --Dr. Seaborg is presently Chairman of the Plutonium has several isotopes, the most important being plutonium-235, which, because ofits fissionable properties ne . and its ease of production, is potentially the best of the three fission fuels. ’ . That is why it is of interest. Aside from its fissionable properties, plu-. . tonium-239 is a radioactive isotope of relatively long half-life (24, 000 years), hence its radioactivity is undiminished within human time scales. When it decays, it emits a helium nucleus of substantial energy. . Because ’ of its physical characteristics, a helium nucleus interacts strongly with the material along its path; and as a consequence deposits its energy in wrehkifively chort distunee, -caubout fourchuncredths of a rmitliraeler in reli pissewe, Por compurison, a typical ccll dimension ig about 1/4 to ‘. oa tee PT ee Committee on Atemic Fnergy, Part 4, March 19, 1970. Times have changed since May 1969. soe eee eee Ut te 'E, ot aoe 2 teas ne Dow weserenss we certs 2M. . oot. BSB EI ‘sotbegeepepeernrersered, coustathyton re be eg opysert wrens 4 Gae eer Shwe ew beer — eert st fF Fol on Tb adebe Fens ds Rodeos a ilarwe teabn Vee Py Bel OE ee bbs ng wh batered 2 F. Tells AE BBTy otals Tad a "4 ee te er S € tener wene ee @