‘ mmpousrene - a Task Group 7.1 SPO 187 (HOW) P.O. Box 8 c/o Postmastor San Francisco, California TU=13—54-375 SUBJECT: 12 March 1954 Radiological Survoy of Downwind Atolls Contaminatod by BRAVO 1. Acknowledgement, The members of the survey tcam wish to express their appreciation to tt Captain, officors and members of the crow of the USS NICHOLAS (DDE 449) for the! assistance and cooperation in conducting tho survey horcin roportcd, Captain Elliot turned over all possiblo facilitics of his ship in order to assist in th: survey. LT Frink, the Executive Officcr, organizcd all the operations of the boat partics, and it was only through his personal dircction and participation that it was possiblc to carry out the small boat survoys under oxtremly diffic: ecnditions, Since most of the lagoon witers woro not navigable by a DDE, it wa: necessary to make long boat trips in high scas and land m tricky coral reefs. That it was possible to make, without mishap, a detailed survey of fivo widely scparated atolls in the course of thrcc days with only two boats was Yargoly a to his efforts. 2. , Introduction The BRAVO Shot contaminatcd a number of atolls in gorcrally castward direction from Bikini to such an oxtent that it became necessary to ovacuatc th native populations from Rongelap, Alinginae and Utirik Atolls and the military perssnnel on Rongorik Atoll, Following this cvacuation CJTF SEVEN organized th subject detailed radiological survey of the atolls to the castward of Bikini (Ref. CJTF SEVEN Eniwetok 060400Z), The date from this survoy woro required fo the following purposes: , a The evaluation of the radiation effects on cvacuccs, b. The cstimation of the clapsed time before rcoccupancy. c. The cstimation of the residual radiation effects of large yiclds surface dcetonations. In connection with this survey, tcams from various Task Groups and Mr. Wilds, Trust Territory Representative, returned to the atolls to secure the cvacuatcd habitations, service military cquipment, and obtain documentary photo graphy. 3. Seok Lo, A. me OS “2C Qperational Schedule 8 March - 0800 ; Survoy tcam rendezvous aboard USS NICHOLAS (DDE 449) in Rongclap Lagoon. ann SRD-213-S4-3E Guoy. 4lows Ve. ee, -