— =HATER Sample No. atoli island Date Mr /Hr L 2 Rongelap Rongelap 8 Mar 300 © 3 Sungelap 8 Mar 9390 * Rongelap Rongelap .central cistern) Rongelap (North part of village) Rongelap (Northernmost cistern ) 6 Mar 400 5 Ot irik cistern ) Utirik (eistern near church) 8 Mar 9 Mar 2=® 4O 7 Rongeri k Eniwetak (Distillation water) 10 Mar 5 Vt dur uc Rongelap (Southernmast Utirik (cistern at. south of village) 9 Mar LO 240 In addition to the above, a sample of fodlago was takon at the wind- ward side of Bikar island, at this point. 8. “he radiation fteld was 180 orfhr o 9 March 1954 Conclusions and Recommendat lons a. The radiological survey proved that a large yield surface detor-. tion can produce extremely serious radiological contamination over a distances more than 20 miles downwind and important contamination about 250 miles dow wind, &. The center of the contamination pattern from the BRAVO Shot lie: samewhat north of Rongelap and Rongerik Atolls and probably not far froma L between Bikini and 2kar, ¢. Although the fall-out was serious on Rongelap Island located at the extreme southeast tip of the atoll, the contamination was about ten times greater at the acrth side of the atcll, twenty miles away. d. The camtamination decreased by a factor of about eight over the downwind distance of 50 miles between “Nongelap and Rongerik. e. Standard military field scusing provides a sigificant degree of protection to personnel inside, f The AN/PDR-39 proved to be a very satisfactory instrument for g. A single DDE with two (2) whale boats is not a completely satis— field survey work under rigorous environmental conditions. factory method of conducting a broad radiological survey of the type jut completed, Future surveys should »isider using vessels capable of entering more of th atclis and cf hardling » cclieopter and several small boats, 6 Incls: L. Rad. curvey Rongelap 2. Rad, curvey Jtirik 3. Rad. Gurvey Bikar AFWL/No 4. Rad. ‘urvey Rongerik S. Rad. urvey Aillinginae 6, Summary cf Rac. Survey 3s’ Herbert Scoville OR. HERBERT SCOVILLE Technical Director AFSWP ; és 7