TABLE 1 H+l Hour Reference Time Dose Rate Contour Areas and Downwind Extents for Various Yields Yield (Surface Burst, 15 Knot Scaling Wind) 3000 r/hr 1000 r/hr 300 r/hr Areas in Square Miles 100 r/hr 15 KT 25 KT 50 KT 0.1 0.18 0.4 0.5 0.9 1.9 100 KT 500 KT 1.0 6.0 4.0 38 17 100 55 450 70 250 800 1M 14 5M 10 MI 15 Mt 100 300 520 2.2 4.0 8.2 8.0 1 27 560 1800. 5400 1500 4200 12,000 2500 7000 20,000 DownwindExtent from Ground Zero in Miles 15 xT 0.8 2.0 4.5 9.6 25 kt 1.2 2.7 6.0 13 50 kt 2.0 4.2 9.2 20 100 KT 3.3 7-0 500 KT 9.5 14 30 19 37 70 1m 15 29 54 100 5 Mr 10 Mr ho 62 76 120 lho 200 230 330 15 Mr 80 150 250 400 For recovery planning, these contour areas are very useful in that times of entry into an area for decontamination or recovery and the time of stay in the area so as not to exceed a predetermined radiation dose can be estimated. However, readings on radiac survey instruments must be relied upon for integrated radiation received during the actual operation, as well as for delineation of the true contour patterns involved. 38