H3..DCU. REERS JOINT T..SK FORCE SEVEN Washington 25, D.C. _9=3/729.3 | ll Docenbor 1953 SUBJICT: Radiolugical Hazards in tho Marshall [slenca .rea During C..STLZ Oe Ccamander in Chief, U.S. Pacifie Fleot o/s Floet Post Offiss San Franeisec, Caif.emia a l. ber 1953. . References: a. CINC?..CFLT SSCRET letter, subject as above, datad 31 Cctc- b.. CJTF SIVEN SICRET letter to CINC?..C, subject: "Schedule ce. CJTF SEVIN SSCAET letter’to CINCP..C, subject: "Safety cf ilessagea Concerning Detonati:n During C..STLE," dated 3 December 1953. cleasures During Operaticnal Phase of C..STL&," datod 1) Docenber 1953. 2. Inforantion presented in your lettor hos beon considcred in the rovised C..STLS radsafo plier (rofarencetc). C.omante cn critical paragraphs cnd details ca oricory oatters of inturest are prossntcd balow fer ycur infcrantica. 3. Reference parcgraph 2 cf your lettor. _.. Se In ecnsdderati:n of your reapensibilities anc boccuse cf othes-Naite force developments since July 1953, the cloud trreking effcrt cn Opdrett.fGaSTLS Has been sugmented. It ischAsidsred thit the creas of acet eunee®n, im sequence cf pricrity intorsst, are as fcll.ws: - S*"(L) The dewnewihd (treds wind) rogicn fren Ground Z3rc0 (GZ). This ares would include bcth the task force canp at iniwotck and the nativepcpulstead stoll of Ujelang. (2) The up-wind (trade wind) regica froa GZ. This is the region fica whidh seccndary faltcut could cceur “n tha task force carp sito. (3) ‘The up=wind (trade wind) rogi.o from the native pcpu- lated atclis in the eutheost quadrant. This area is of ecncern fcr the same reason ag 3a(2) abowo, but ecnsidered cf less pricrity cue to its more fsver-ble lccatiica with reapect to GZ. Inel 5 to TAS nor a