Protection a. Against the primary radiological effects, distance willl provide protection, b. Against the secondary radioactivity hazards from radio tive fission products, induced radioactivity and unfissioned resi tion and avoidance provide the best protection. Suitable nstruments indicate both the presence and intensity of radioactivity t a given place. Area reconnaissance, the maintenance of contaminat on situation maps, the posting of areas of hazard and minimizing t e spread of contaminated material into uncontaminated areas constitute the active e, detec- measures for reducing the radiological hazard. c. Personnel within an operational radius of ground zero w facing in the direction of the flash will be required to w goggles to protect their eyes against excessive light. Pe within the above operational radius who are not provided g face, with eyes closed, in the opposite direction from the After ten (10) phenomena. seconds, such personnel may turn around and Anticipated Hazard Areas a. Immediately under the bomb burst there will be an area radioactivity extending downwind and, to some extent, cros upwind with gradually decreasing intensity. b. Extending downwind (and to some extent, crosswind and ugjwind), an airborne radioactive hazard will exist. Its characteristids will de- pend on the meteorological influences such as wind speed a at various altitudes up to the maximum height reached by tite direction cloud. c. Contaminated water in the lagoon adjacent to the shot sifte may be of consequence and will be analyzed by the radiological saffety unit of TG 7.1 immediately after shot time and at other intervals. d. Unless care is exercised, individuals or objects entering nated areas may transfer radioactivity to clean areas. e. By means of instruments such as Geiger-Mueller counters contamifand ion chambers it is possible to detect the area of contaminationj and to measure the intensity of the radioactivity. Radiation intehsity will normally be measured and reported in roentgens per hour. Sides those instruments, dosimeters and film badges will be used fs indicators of the accumulated exposure to radioactivity. Only pefsonnel involved in work near, or in, radioactive areas will wear film badges to provide a permanent record of exposure, except that film badges will be issued to ten (10) percent of ship crews to aid in Estimated crew dosage in the event of heavy fall-out. f. The intensity of the radioactive hazard tends to decreask with time due to decay of radioactive materials and dispersion and dilution, depending upon climatic conditions. As an approximation, thef intensity 463