Co. SUBJECT: ae cd by BRAVO Radiological S:urvey of Downwind itolls Contaminat that onc survey meter could not be properly zcro adjustcd. The four remining -N/PDR~39, still operate: cfficicntly and sccmod to be in good working ordcr, One (1) cach Bekman MX-5, and one (1) cach AN/PDR-27A was brought alor ‘for any low intcnsity checks necessary. Two (2) cach calibrated AN/PDR-T1B, we? on hand to servo as spars in the ovont of opcrationel failuro with the IN/PDR~, . None of these instrumcntz wero roquircd, 6, Tho avorago and maximum gamma doso ratos measured on tho various islar All measurcmnts wore mde ai of cach atoll are plottcd in Figures 1 through 5, The mximum roadings do not includo waist height unless othe=>wise indicatcd, measurements mde with the instrument next to a contaminated surfaco, Dotailed surveys wero made of all the inhabited localitics. Typical of Rongclap Island, readings aro givon in Tables 1 and 2 for the nativo’villago In gencral, tho villages and the camps and the 1G 7.4 camp on H-iwctak Island, remainder of tho appeared to have slightly lowcr average dose rates than the natiar 4sland, This can perhaps bo ascribed to different geomotry of the contami . village’ nativo and to slightly greatcr penotration into the loose gravel in the £s tho doe The doso rates insido the nativo huts appoared to be almost tho same rate outside, s, tcnts, and! The doso ratc in the middio of tho military barrack largely a gcoom shacks ws 1/3 to 1/2 thet outside, This reduction is probably mrk, effect. The dose rato fcll off rapidly on tho beach bekow the high. tide foila; The mtcrial nated contami the Thoro was no evidence of rain washing off slightly above avcrago con— on the windward sides of the islands appcarod to be tamination. (eee ee ee ee ABB Ee “TyPICAL READINGS IN RONGELAP VILLAGE — 8 MARCH location = -——— mT a Dose Rato (aorfor ) Rongelap Island (avorage) Center of village Near central cistern’ ' Near southorn cistorn Near northorn cistern 375 280 300 220 350 ‘TABLE 2 TYPICAL READINGS IN CAMP ON ENIWETGK IS. — 10 MARCH ‘Outside Dose Location Eniwotak Island (averago) oe Mess hall 270 - , Slecping quartcrs Dispensary 280 220 |. Tent, edge of main camp Latrino “Inside Doso * Rato (mr/hr) _ 260 260 22 Rate-(mr/hr) =: . . _. D0 175 160 . *s. 30 110 es