Sample No. Atoll Island Date ur /Hr 1 2 Rongelap Rongelap 8 Mar 300 3 Rongelap 8 Mar 350 4 Rongelap 8 Mar 400 5 Utirik Rongelap (central cistern) Rongelap (North part of village) ; Rongelap (Northernmost ~ cistern) Rongelap (Southernmost cistern) 8 Mar 220 6 Utirik 7 Rongerik Utirik (cistern near church) Utirik (cistern at south of village) 9 Mar 9 Mar Eniwetak (Distillation water) 10 Mar L0 LO 24,0 In addition to the above, a sample of foilage was taken at the wind- ward side of Bikar Island, at this point, 8. The radiation field was 180 or/hr on 9 tarch 195); Conclusions and Recommendations ae The radiological survey proved that a large yicld surface detor::. tion can produce extremely serious radiological contamination over a distance. more than 120 miles downwind and important contamination about 250 miles cow: wind. b. The center of the contamination pattern from the BRAVO Shot lic: somewhat north of Rongelap and Rongerik jtolls and probably not far froma lL: between Bikini and Bikar, Ce Although the fall-out was serious om Rongelap Island located at the extreme southeast tip of the atoll, the contamination wes about ten times greater at the north side of the atoll, twenty miles away. d. The cmtamination decroased by a factor of about cight over the downwind distance of 50 miles between Rongelap and Rongerik. e, Standard military field housing provides a sigqificant degree of protection to personnel inside, f. The AN/PDR-39 proved to be a very satisfactory instrument for ficld survey work under rigorous environmental conditions. g. A single DDE with two (2) whale boats is not a completely satis— factory method of conducting a brosd radiological survey of the type jut completed, Future surveys should consider using vessels capable of entering more of the atolls and of handling a helicopter and several smil boats. COPIED/DOE LANL Ro 6 Incls: 1. Fad. Survey Rongelap 2. Rad. Survey Utirik 3. Rad. Survey Bikar 4. Rad. Survey Rongerik 5. Rad. Survey Anginae—age% 6, /s/ Herbert Scoville DR. HERBERT SCOVILLE Technical Director AFSYP oe y VF