CLOUD TRACKING CFERaTIONS FOR BRAVO ‘> [plea 8 March 1954 @ 1. SUMMARY: The BRAVO Air Rad Sefe Operations were conducted essentially as planned. No hazardous air coataninations were ene countered by aircraft other than the samplers. Several eircreft and crevis were exposed but the levels encountered appear acceste able from both a health and a decontarination aspect. Comsuniceae tion and control difficulties made it difficult if not impossible to forecast the fallout in the Rongerik/Rongelep ereas. Steps we we have been taken to remedy the defects whick became arperent during BRAVO operations. 2. GENERAL: : Cloud tracking information for BRAVO was derived fran five sources. The manner in which each of these functioned curing BRAVO will be discussed individually in subsequent paragraphs. These sources were as follows; Sampling aircraft reports. - Sweet-sour reports. Speciel Cloud tracking flights. Weatner reconnaissance flights. AFOAT-1 3. flights e SAMPLING ATRCRAFT REPORTS: These reports were monitored and recorded by Pad Safe personnel eboard BOUNDARY TARE frox plus two thru plus seven hours. Information derived from these reports indicated the sazpling aircraft were working the South and Southeest edge of the cloud and therefore stayed in the immdiate viclaity of Ground Zero. Because of the altitude of the sanpling operations (30,000 - 45,000 ft) there is little relation between the Cperation of these aircraft and subsequent air o> ground contacination. This data; nowever, does assist the sir Rad Safe Officer &n ob- taining an overall picture of the dispersal of radioactive materiel. No reports'of cloud cuovement were received from the control B-3 aircraft. 4e oY/ / S.EET@SOUR_ REPORTS: "hese reports are subcitted by any eizrcrast encounce ring radioactive contamination and =ot reporting by otner Eeens. no such reports were received during B=avo. Tris is not Surprising since aircraft other than the samplers and trackers [reporting oy otner means) seak to avoid arees in which contacinet.o2 is suse pected. - a ee