JOINT TSK FORCE SEVET SK CROP 7.3 ae 72OT, 0/0 Postmaster ‘Se, ame 2. essen - c, Califomis San Freneise . 4 iF 93/7.3/S2:08 S15 Ser: 00666 ee “ : 22 Maren 1958" Froms Coamender, Task Group 7.3 Ter Chief of Naval Operations . Vias (2) Comarca Joint Tonk ron Posifie 2) Comander in Ciief, U.$o Facifis Fleet Subj: Rodicactive Contaxination of Ships and Radiologica? Exposure of Fersome of Task Group 7.3 due to BRAVO, the Pires Nuclear Explosion of C.STLE . Ref: (a) CTO 7.3Conf dispateh 1307332 of Marek 195% Encl: (1) Diagram indicating positions of 10 7.3 ships from H hour until about 0425, 1 March 195k. (2) Tabulation of average topside radicective intensities of Task Group 7.3 ships, at various tines following MU.VO. . (3) Tabulation cf securmmlated radiological exposures of Task personnel by shins and units. (4) BATROKO (CVE 115)sceres serial C010 of 12 March 195k» <up 7.3 . 1. Om 1 March 1954, st 06491, the fires nmalear exploaion (ERLW) of Operation C.STLE was detomatod. Prior to the detonation, ships of Tasik Group 7,3 had been deployed et sea generally in the southeast quadrant indicated in cnelosure (1). ‘This disposition and its location wre based four principal factors, (8) the latest CJTF SEV! radeax, (b) the repirenente of the Commander Scientific Task Group (CTG 7.2) that ESTES (,0C 12) and CURTISS (.V &) be positioned about 12 niles from NYU Island for reliable UHP commnications and Raydist purposes, (c) the requirenent that ships be disposed at safe distances (at loast 30 miles) from ground sere to heat, and blast effects, and (d) the requirement of reasonable concentration for soamamications and control purposes. Pricr to the detonati later wind data began to indicate an eastorly component, some of the smaller and slower unite were directed to move to the sath, but the larger ships were retained in the localities. indicated in view of the foregoing requirensnts (b) and (4) and the expressed desire of the JTF Ccoamander that thay not be moved. Because of the additional requirements for early holicopter surwy tripe and the early dispatch by helicopter of an emergency airfield crew for the airfield on ENINMN Island, the large ships were retained generally in their pre-shot positions after the detonation until about O@00M, when sudden ond rapidly increasing radioactive fallout was detected on some ships. «t this time, all ships were ordered to take all possible radiological defense demage control measures, including the employment of washdown systems, and to proceed to the south at best speed. SRD-229-54,E INCLOSUL ES K~=50 =...