(FLATHEAD) Project 2.65 - Analysis of Fallout and Base Surge - M. Morgenthau Objectives The general objectives of project 2.65 participation in REDWING were to: (1) obtain fallout samples on land and to perform radiophysical and radiochemical measurements on the samples; (2) prepare dose rate contours of the atoll area from information gathered by this project, other projects, and Rad-Safe; and (3) evaluate the role of the base surge in transport of radioactive material, Description and Experimental Procedures: Stations at Eniwetok Atoll were equipped with a Gross Fallout Collector (GFC). On D-Day, D #1, and D # 2, an aerial survey of residual radiation was made over the respective atolls by helicopter. The measurements were taken by means of a probe on a long cable suspended below the hovering helicopter. The position of the probe was determined by comparison with maps and aerial photographs. Results Aerial survey readings taken on three successive days were corrected for meter calibration and corrected to H #1 hour and H # 12 hour values as shown in Table 2.65=1 by using the decay exponent of ~1.0. The field readings taken on three successive days were plotted as a function of time for seven representative islands. The average decay exponent for the period H # 8 to H # 55 hours was found to be -1.015. Analysis of intermittent fallout collector data, particle size data, and radiochemical data is in progress. collected, map r¢ te . a aNT ORG f e a LOE rey ¢7°FiED/DOE Very little liquid fallout was 26 4