HEADQUARTERS TASK UNIT 13 Task Group 7,} APO 187 (HOW) P.O. Box 8 c/o Postmastor San Francisco, California TU~13-54-375 SUBJECT: 1. . 12 March 1954 Radiological Survey of Downwind tolls Contaminatod by BRAVO Acknowledgement Tho membors of the survoy tcoam wish to express thoir appreciation to * Captain, officers and monbers of tho crow of the USS NICHOLAS (DDE 449) for the. assistance and cooperation in conducting tho survoy horein roportcd, Captain Elliot turned over all possible facilitics of his ship in order to assist in thc survey, LT Frink, tho Executive Officcr, organized all the oporations of tho boat partics, and it was only through his personal dircction and participation that it was possiblo to carry out the small boat survoys under cxtremly diffic: conditions, Sinec most of the lagoon waters woro not navigablo by a DDE, it wa: necessary to make long boat trips in high soas and land on tricky coral rocfs, That it was possiblo to mako, without mishap, a detailed survey of five widely scparated atolls in the courso of threo days with only two boats wis largely du to his efforts, 2. Introduction Tho BRAVO Shot contaminatcd a number of atolls in gerrally castward dircetion from Bikini to such an axtont that it becamo necessary to ovacuate th native populations from Rongelap, Alinginac and Utirik Atolls and tho military persgnnel on Rongorik Atoll, Following this cvacuation CJTF SEVEN organized tt subject detailed radiological survey of the atolls to the castward of Bikini (Ref. CJTF SEVEN Eniwctok 060400Z), The data from this survey were required fo the following purposes: a. The evaluation of the radiation effccts on cvacuccs, be The ostimation of the clapsed timo before rcoccupancy. c. The cstimation of tho residual radiation effects of large yiclds surface dctonations. In connection with this survey, tcams from various Task Groups and Mr, Wilds, Trust Territory Representative, returned te the atolls to secure the evacuated habitations, servico military equipment, and obtain docummtary phote graphy. 3. . Operational Schedulo 8 March ~ 0800 Survoy tcam rendozvous aboard USS NICHOLAS (DDE 449) in Rongelap Legoon. ' wa SRD- 2I3-SY-3E