could have modified the distribution of radionuclides. Phase III deals with islands which have been sites for, or very near to, surface ground zeros and/or extensive test activities. Contamination exists in the form of activated metal debris, radioactive waste disposal areas, distributed fallout, and localized plutonium contamination. The survey will also include an estimate.of the extent of radioactive scrap metal situated on these islands, Finally, Phase IV addresses Runit (Yvonne), the most heavily contaminated island. The selection process for survey priorities is based upon insult determination of each island from examination of historical records and current radiological data provided by preliminary surveys of Eniwetok Atoll in July 1971, May 1972, and of Runit in July 1972. Field Meter Survey The survey includes a very detailed examination of the geographical variability of the gamma exposure rate in air on each island due to the gamma rays of greater than 100 Kev emitted by radionuclides deposited in _the soil. These nuclides are primarily fission and neutron activation products, The Baird-Atomic scintillation instrument, which utilizes a .1" x 1" NaI erystal, will be used to make these measurements. Similarly, the flux of gamma rays of energies less than 100 Kev due to 239py and 241an will be measured by the FIDLER, This instrument consists of a rf " thick x 5" diameter NaI crystal connected to a rate meter. The geographical variation of these measurements will enable the survey teams to locate the areas contaminated with radioactivity where soil samples may be collected for laboratory analysis to determine the concentrations of specific radionuclides present. Aerial’Radiological Measurements. This method has been used by EG&G, Inc. for several years for rapidly ‘and economically surveying large land areas for radioactive deposition and for the location of lost radioactive sources. The data provided by such a survey will be extremely valuable in guiding the field survey teams in the conduct of their surveys. It will greatly reduce the possibility of the survey teams missing contaminated areas and at the same time increase their efficiency by eliminating their need to extensively survey uncontaminated areas. CBdoe The EGRG airborne radiation detection system that we propose to utilize «12.