The program established an organization to provide radiological (radsafe) expertise and services to the separate components of Personnel were trained in radiological safety, and standards go maximum permissible exposures (MPE) were established. Film badg provided to a large portion of the participating personnel. Per likely to be exposed to radiation were badged as well as a repre group of the remainder. An extensive weather forecasting group lished in order to predict wind directions and areas of potentia Personnel were evacuated from danger areas before each detonatio entry to contaminated areas was restricted to the personnel requ retrieve important data. The amount of radiation exposure for these per- sonnel was monitored. TEST OPERATIONS AND EXPOSURES The first event of this series, designated BRAVO, had a yieldjof 15 MT and was the largest device ever detonated in atmospheric nuclear by the U.S. Government. festing Significantly exceeding its expected yield, BRAVO, detonated at Bikini Atoll, released large quantities of radioactife materials into the atmosphere, which were caught up in winds that sprdad the particles over a much larger area than anticipated. This resulted in the contamination and exposure of some individuals either stationed og resid- ing on distant atolls or aboard various vessels. bffects Acute radiation were observed among some of these people. A limited number of JTF 7 personnel received radiation exposurks considerably in excess of the initially established CASTLE MPE. This] opera-~ tional limit was established at 3.9 roentgens (R) gamma within any]13-week period of the operation. In particular, three members of the U.S.[Navy Bikini Boat Pool had heavily exposed badges with readings from 85 fo 95 R, and 28 Army and Air Force personnel had film badge exposures that dead as high as 78 R. All these men were medically evaluated at Kwajalein sequently, follow-up on 29 of them was done at Tripler Hospital in Sub~ Hawaii.