SUBJECT: Radiological Survcy of Downwind .itolls Contaminated by BRi.VO that once survey metor could not be properly zcro adjusted. Tho four remining -N/PDR~39, still oporated officicntly and scomed to be in good working ordor, @nc (1) cach Bockman MX~-5, and one (1) cach AN/PDR-27A was brought alor for any low intensity chocks noccssary. Two (2) cach calibratcd AN/PDR-T1B, wo: on hand to scrvo as sparcs in tho ovont of operational failuro with the AN/PDR~ None of theso instrumants wero roquirod,. 6. Tho avorago and‘ maximum gamma doso ratos measurod on tho various islar of cach atoll aro plottod in Figures 1 through 5. All moasurements woro mdc ai waist hoight unless othorwiso indicatcd, The maximum readings do not include moasurements made with tho instrument next to a contaminated surfacos. Dotailed surveys woro made of all tho inhabited lecalitics. Typical readings aro givon in Tablos 1 and 2 for tho nativo villago of Rongclap Island, and the 1G 7.4 camp on Mmiwctak Island. In gencral, the villages and the camps appearcd to have slightly lowcr averago doso ratcs than the romainder of tho island. This can porhaps bo ascribed to difforent gcomotry of the contaminatla and to slightly grceatcr ponotration into the leose gravol in the nativo village: The doso rates inside the nativo huts appoarcd to bo almost tho samo as the doe rate outside. The doso rate in the middlo of tho military barracks, tcnte, and shacks was 1/3 to 1/2 that outsido, This reduction is probably largely a gcom effect. The dose rato fcll off rapidly on tho boach below the high tide mark, Thoro was no cvidence of rain washing off the contaminated mtcrial, The foila; on the windward sides of tho islands appcarod to be slightly above average con— tamination. TABLE TYPICAL READINGS IN RONGELAP VILLAGE — 8 MARCH Location | Rato Rongolap Island (average) 375 Noar central cistern 300 Near northorn cistern 350 Conter of village 280 Near southern cistcrn 220 TABLE 2 TYPICAL READINGS IN CAMP ON ENIWET#K IS. - 10 MARGH Location Eniwotak Island (average) Mess hall Tont, cdge of min camp Latrinc Slecping quarters Dispensary Outside Dose Inside Dose Rate (or/hr) Rate Xor/hr) 280 220 -~ pale) “- 26 160 270 220 26 — 175 110 aOR 90