Health Physics Society Annual Meeting, Denver, Colorado, June 16-20, 1968 TITLE: External Radiation Survey of Bikini Atoll May 1967 AUTHOR(S): Harold L. Beck and Burton G. Bennett, United States Atomic Energy Commission, Health NY, Ny and Safety Laboratory (HASL), and Tommy F. McCraw, United States Atomic ergy ADDRESS: Commission, Division of Operational Safety, Washington, D. C. ABSTRACT (double-spaced): Abstracts exceeding 200 words will NOT be considered. — — An intensive radiological survey of the islands of Bikini Atoll was conducted in late April and early May of 1967, nine years after cessation “of extensive testing of nuclear devices in the area. The survey included general observations of the prevailing environmental conditions and a detailed investigation of external environmental radiation levels. Ex- posure rates due primarily to penetrating gamma radiation were measured, and the principal radicisotopes contributing to the total exposure rate on each of the major islands of the atoll were determined. Instrumentation utilized included a field gamma spectrometric system, a high pressure ionization chamber, scintillation and G.M. survey meters, and thermoluminescent dosimeters. A large number of soil samples were taken for laboratory NaI(Tl) and Ge(Li) gamma spectral analysis. Total exposure rates were found to vary considerably from site to site and island to island. Levels measured over soil ranged from less then an C3 os C52 10 »R/hr to over 500 uR/hr with the highest levels usually found in the more thickly vegetated areas. 137 Cs, 60 Co, 125 . ‘ Major contributors to the radiation fields usually _ included Sb, and Cy isotopes were also detected. send this original pius 15 copies to: 102m Rh, although, a large number of other E.G. Struxness, Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, . Tennessee 37830 EADLINE: February 1, 1968