SBavorn«S'EITaves Raa or stone house, and the basement of an average 1 esidence would reduce the exposure to about one-tenth. It has been stated that shelter in an old-fashicned cyclone cellar, witht & covering of earth three feet thick, would reduce the radiat nm dose to about 1/5000. 3, Adequate food and water should be sto sanitation me&sures taken to permit shelter oce cays, ed and proper ancy for several To the extent that concentration of evac sanitation problems will be magnified. es is necessery In the i dividual home, however, it should be noted that people may emer e from the basement for a few minutes at a time without app eciably increasing the hazard, Precautions should be ta en to reduce the possibility of contaminated material getting int area. the protected Surface sources of drinking water, reserv {i and the distribution system should be repeatedly checked for serious radiological contamination and other pollution. C. Operations 1. The greatly increased probability of a radiation hazard makes it necessary that all civ erious residual defense programs be re-evaluated and that necessary changes in operational plans be made. For the purpose of preliminary planning, may be assumed that a city struck by a high-yield weapon will hafPe & serious radiological problem within the "D" ring of blastIdamage and that continuing monitoring will be necessary to provid# information for operational guidance, 2, Certain fixed operational sites, such a# and communications centers must be given special consideration if operations at that location are assembly areas rotective strict necessity. 3. Decontamination may be required for cer facilities such as communications centers, water in essential mping stations, -15- pert... IG