Out to approximately 300 ft, which is beyond the range of probable blast injury, radiation exposures would probably be fatal, being in excess of 750 rads. Between approximately 300 and 750 ft, varying degrees of radiation injury, including some fatalities, would occur as exposures would be between 100 and 750 rads. From 750 to approximately 2,000 ft downwind, little, if any, injury or clinical effects would occur, but exposures would exceed 3 rads and would require administrative investigation and reporting. Beyond approximately 1.5 mile, doses even in the path of the cloud would be below a few hundred millirad, and should present no problems.
The seriousness of radioactive contamination is difficult to assess, since it depends so heavily on the value and potential uses of the contaminated real estate. However, 1 day after the Kivvi-TNT event, contamination exceeding 100 mR/hr was within 1.200 ft downwind and 300 ft upwind of the etst point; the 1 R/hr line at this time was 300 ft downwind and less than 100 ft upwind. By 1 week after the event the 100 mR/hr area was 300 ft downwind and less than 100 ft upwind of the test point. Within a few hours of the test, contamination above 1 mR/hr was difficult to find beyond 2 miles, although a few “hot spots” of several mR/hr were discovered out to 10 miles on the day of the test. These rapidly decayed away to insignificance. Beyond 12 miles, no contamination above 1 mR/hr was found.