([NPUT DATA Surface meteorological observations were avalizole from some atolls anc from the U.S.S. Curtiss which cruised south of Bikini; nowever, since the larger oacticlas fall rapialy from the debris cloud to the surface and spend little time near the surface, not many surface reports were used. Of far greater importance are the upper air wind observations taken at four sites near Bikini atoll. Other significant input data consisted of a flat topograohy, cell sizes of 34 km (east-west) by 17 km fnorth-south}, and | km in the vertical, stem and cap debris cloud geometries at Stabilization time, source rates for both gross fission products and selected individual nuclides, and particle size spectrum parameters. CALCULATIONS Geoss Fission Products The time-integrated external dase oattern (in rads) due to gross fission oroducts from detonation time to evacuation time of Rogelao atoll (51 hours) are snown in Fig. 1. Tne numbers next to Ailinginae, Rongerix, and Utirik atolls are integrated values up to the time people were evacuated from those atolls. For : [6 Strauss” comoarison. the value . ‘ are given in Table 1. of total dose, Note that estimated by Dunning (3] and the agreement is very good for Rongelap and Ailinginae atolls. However, calculations for Rongertk and Utirik ace at odds with earlier estimates. The code calculaticns for Rongerik are higner, while those for Utirik are lower. This variation appears to be in part a problem of "tuning'’s also a possible variation in wind directions and speeds at late times when the only wind observations were from the U.S.S. Curtis, souta of Bikini (some distance from the atolls of concern) may be an explanation.