CONFEDENEHEall cep from 4000 to 12,000 m. Whenfallout is considered, the superiority of evacuationis reduced and perhapseliminated, depending on the local and regional fallout pattern. 9, Any increase in radiation effects resulting from attacks on other nearby targets will increase the effectiveness of underground shelter relative to the other possible civil defense tactics. This relative superiority will be most drastic when the total fallout intensity reaches a level where the 0.9 protection factor of best shelter now available permits occupants to receive a lethal dose. 10. Shelter that will attenuate radiation effects by 0.9 (ordinary basement shelter) is not adequate in urban targets: a. At 2 to 4 miles from ground zero, individuals in basement shelters would receive an LDso dose in 3 hr, at 4to 5 miles, in6hr. At these distances fallen trees and other debris in a high radiation field would make rescue operations impossible within the hours of life left to occupants of basementshelters. b. At distances that might be relatively debris-free (7 to 8 miles), LDgq doses would be received by occupants of basement shelters after 24 hr. Evacuation by shielded vehicles would be imperative to preservelife. 11. Since immediate postattack rescue and evacuation efforts may be impossible because of high radiation levels, public and private shelters need to be designed and stocked to permit survival within the shelter for periods as long as 10 days. 12. With widespread attack on many targets, mass evacuation tactics could result in 100 percent lethality among the evacuated population. This could be true even if the evacuated city were not itself successfully attacked. 13. The cost of an evacuation program for 170 major cities should not exceed $50 million in direct costs for plans, maps, and traffic signs and recruiting, training, and equip- ping traffic control personnel. Indirect costs due to loss of wages, output, and profits are not considered in this estimate and would be very high, especially if the enemy developed “spoofing” tactics. 14. The cost of combination public-private shelter programs is largely dependent on the degree of protection desired. Two programs considered in this appendix are estimated at $6 billion and $33 billion each for 170 majorcities. RECOMMENDATION 1. The Army should support the following activities: a. A start should be made on a reduction-of-vulnerability plan and an underground shelter plan for each metropolitan target area, looking toward reduction of target values in the core area and a spacing of underground shelters to match future population dis- tribution at the expected date of ultrashort warning for IcBM. b. Construction of underground shelters should be started as soon as firm longrange shelter needs in any geographical subdivision of the metropolitan target area can be determined. The current “survival studies” being undertaken by various cities with federal funds should be utilized to determine local shelter needs rather than to designate evacuation routes. c. The entire civil defense concept of postattack operations should be reexamined in light of probable high radiation levels that may render traditional rescue, medical, fire fighting, and other services at or near the site of the attack impossible. d. Intensive r«p effort should be expended on testing existing shelter designs and on the design of multipurpose and improvised shelter. 68 ORO—R-17 (App B) — Costs