radioactive fission producte, As a rule, this contamination will persist for unusually long periods of time, depending upon rate of radioactive decay, dispersion and dilution in the water and other factors. OBJECTIVES OF A PLAN FOR RADIOLOGICAL DEFENSE The primary objectives of the radiological defense plan should be: a. To prevent or mitigate personnel injuries resulting from exposure to radiological hazards, through detection and avoidance of such hazards; >. To facilitate the work of relief and the restoration of essential services, through the protection of personnel whose civil defense duties require their entry into radiologically hazardous areas; and Ce To prevent or minimize confusion and panic, through the collection and proper dissemination of factual information concerning the existence, or non-existence, of radiological hazards, SPECIAL CONSIDERATIONS IN PLANNING FOR RADIOLOGICAL DEFENSE The peculiar characteristics of atomic attack present new and highly technical problems of defense, requiring special consideration in all phases of radiological defense planning, The more important of these are: Detection and Avoidance of Radiological Hazards the Basic Principle in Radiological Defense. Assuming lack of warning of attack and consequent inability to utilize availeble shelters, little can be done to protect persons within 3,000 yards of the point of bomb detonation from the extreme radiation x4 8 rom ARnenh