92 CHAPTER V RADIOLOGICAL CONTAMINATION OF PERSONNEL ON BRAVO SHOT 1 Several hours after BRAVO was detonated on 1 March, high intensity radioactive fall-out began to appear on the atolls to the east of Bikini. It started at approximately H plus five hours on Rongelap and Ailinginae, at H plus eight hours on Rongerik and several hours later at Utirik. four atolls were inhabited, All Rongelap was populated by sixty-four natives; Rongerik by twenty-five airmen at the weather station and three Project 6.6 personnel from the Army; Utirik by 154 natives; and Ailinginee by eighteen natives. Because of communication and logistic prob- lems, evacuation of Rongelap did not start until H plus fifty hours, followed by Ailinginae at H plus sixty hours, Rongerik at H plus twenty- eight hours, and Utirik at approximately H plus eighty hours.. _Rongerik, approximately 130 nautical miles from Ground Zero, was the only atoll in the group that had any radiation detection devices or dosimeters. Twelve film badges had been assigned to the U. S. personnel at the weather station, along with a recording rate meter being operated for the New York Operations Office of the Atomic Energy Commission. The rate meter went off-scale at 100 mr/hr at approximately H plus eight hours. The film badge readings were only regarded as approximate because of confusion as to the locations of the badges during the fall-out period. Six badges were in the refrigerator and registered 37 t 37.5 1r. The badges carried, or in posséssion of USAF personnel, measured 40 r.? The one badge in the possession of Army personnel (working on the other end of the island) registered 98 r. AFWUHO | g3