situation maps, the posting of areas of hazarc . cinimizing the spread of contaminated material into uncontamics::: areas constitute the active measures for reducing tne radiological nazard. c. Personnel within an operational radius of ground zero who are to be facing in the direction of the flash will be required to wear spe- . 3. clal goggles to protect their eyes against excessive light. Personnel within the above operational radius who are not provided goggles will face, with eyes closed, in the opposite direction from the — flash. After ten (10) seconds, such personnel may turn around and observe the phenomens. , Anticipated Hazard Areas a. Immediately under the boub burst there will be an area of intense radioactivity extending downwind and, to some extent, crosswind and upwind with gradually decreasing intensity. b. Extending downwind, and to some extent, crosswind and upwind) an airborne radicactive hazard will exist. Its characteristics will de pend on the seterological influences such as wind speed and direction at various altitudes up to the maximum height reached by the cloud. ce. Contaminated water in the lagoon adjacent to the shot site may be of consequence and will be analysed by the radiological safety. unit of TG 7.1 immediately after ahot time and at other intervals. ad. Unless care is exercised, individuals or objects entering con-- e. By means of instruments such as Geiger-Mueller counters and ion taminated areas may transfer radioactivity to clean areas, ” chambers it is possible to detect the area of contamination and to measure the intensity of the radioactivity, Radiation intensity will normally be measured and reported in roentgens per hour. Besides those instruments, dosimeters and film badges will be used as indicatora of the accumulated exposure to radioactivity. Only per- sonnel involved in work near, or in, radioactive areas will wear fila badges to provide a permanent record of exposure, excspt that film badges will be issued to ten (10) pereent of ship crews to aid ia estimating crew dosage in the event of heavy fall-out. f. The intensity of the radicactive hasard tends to decrease with time due to decay of radioactive materials and dispersion and dilu- tion, depending upon climatic conditions. As an approximation, the intensity of the surface contamination from the fission products decreases by radioactive decay inversely with the time after the detonation. As-a further approximation, the intensity of water contamination decreases by radicactive decay and diffusion inversely with the square of the time after the detonation. 4. Q This appendix has been desiged for reduced security classification in order to permit wide dissemination to all personnel of the command and may be downgraded to RESTRICTED - SECURITY INFORMATION provided all references to Joint Task Force SEVEN and its subordinate units are deleted. AL , P. W. CLARKSON ° J Colonel, U.S. AirWorce, Assistant Chief of Staff, J-3,..., Major General, U.3. Arny Commander A-17 ||