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 B-29s, single-seated aircraft, and those other aircraft so designated by CJTF 1 as exempt. The crewmembers of all aircraft aloft during that period were to wear film badges, and each aircraft was to carry at least one casualty badge capable of recording radiation much higher than personnel film badges. In actuality, these plans were modified somewhat for both shots. For shot ABLE, radiation monitors were aboard all photographic aircraft, reconnaissance aircraft, drone control aircraft (except the Navy F6Fs), air-sea rescue aircraft, and press/observer aircraft. The F6Fs were single-seated, fighter-type aircraft in which radiation monitoring equipment was installed for the pilot's protection. On shot BAKER, radiation monitors were aboard all photographic aircraft, reconnaissance aircraft, and press/observer aircraft (Reference C.9.206, pp. VII-(C)-10 and VII-(C)-19).

The prohibited airspace for aircraft was defined separately for each of the two tests and was a function of time and range. For the first 6 minutes after detonation, no aircraft was to approach closer than 10 nmi (18.5 km) to surface zero. From H+6 to H+30 minutes, a radiation danger sector (radex) was defined, consisting of two bearings drawn from surface zero, e.g., 320° clockwise to 120°. From H+6 to H+18 minutes, the aircraft exclusion area consisted of all space in this sector within the Red Arc. From H+18 to H+30 minutes, the exclusion area was all space in this sector within the Blue Arc. The Red and Blue Arcs were decided upon based on wind speeds the morning of each detonation. The morning of each shot, the radex sector was updated from the one predicted the previous evening. The Red Arc was, by definition, nearer surface zero than the Blue Arc. Specific values for radex sectors and the Red and Blue Arcs for the ABLE and BAKER shots are discussed in Chapter 4 (Reference B.0.6). In addition, no aircraft without radiation detection instrumentation was to approach closer than 20 nmi (37 km) to the visible column or downwind clouds. From H+30 minutes to H+30 hours, no aircraft was to be within 30 nmi of surface zero unless engaged in radsafe work or cleared by the Deputy Commander for Aviation (Reference B.0.1, p. F-XII-3).

All aircraft, manned and drone, airborne from H-hour until H+30 were to be monitored upon landing. Aircraft oil filters and any surface oil spots were to receive special monitoring attention. All drones were considered heavily contaminated until proven otherwise (Reference B.0.1, pp. E-IV-3 and E-IV-4).

STAFFING AND TRAINING

Selection of Personnel

When the Radiological Safety Section was established in January 1946, it was believed that 50 to 60 monitors would be needed. Between 20 and 30 were to be experienced radsafe practitioners from the Manhattan Engineer District and thirty were to be doctors from the Army, Navy, and U.S. Public Health Service. The latter group, including a chemical warfare officer, reported to Oak Ridge National Laboratory on 15 January for an intensive 11-week course. The course included the physics of radioactivity, nuclear safety techniques, biological effects of radioactivity, field training, and hazards of ingested radio nuclides. Experts from Oak Ridge and Los Alamos laboratories and from the Universities of Rochester, Chicago, and California at Berkeley provided instruction (Reference C.9.206, p. VII-(C)-4).

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