ABSTRACT An intensive radiological survey of the islands of Bikini Atoll was conducted in April-May 1967 for the purpose of determining the levels and components of the external gamma radiation fields in this former weapons testing area. Fourteen islands and the two island complexes of the atoll were surveyed with instrumentation which included a field gamma spectrometer 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 Nafr(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 500 ur/hr. than 10 uwr/hr to over Major contributors to the radiation fields usually included **’cs, *°co, **®sb, and *°*™Rh with a large number of other isotopes present. The large amount and consistency of the data indicate that a reliable and compre- hensive picture has been obtained of the external gamma radiation environment of the atoll. DOE ARCHIVEg - iii -