More background details on the military and civil defense participation are given in Section Five. Smali to large groups of Congressmen and other public offi- cials have attended many detonations in all Nevada series. group of NATO observers witnessed the May 5, 1955, shot. A Costs of Nevada Tests Exact costs of Nevada test cperations, even aside from the cost of fissionable materials expended, have not been segregated and probably cannot be. It was estimated that the cost of the originally-scheduled ten shots in the Spring 1953 series would be about. $15,000,000 for the AEC and about $15,000,000 for the DOD, or approximately $3,000,000 a shot. rough estimate. This still may be a fairly Postponements In the five series, there were approximately 103 postponements or delays. More than 80 were caused by unacceptable weather. Other causes included: aircraft engine failure, one; construction, one; delays in instrumentation, three; aircraft operations, two; contamination of firing areas by previous shots, two; one shot was prevented from detonating by a built-in checking device when a key experiment was not receiving data; another did not detonate because of failure in an electrical connection. A majority of postponements for weather were day by day, but when air drops were involved the initial postponement was usually 48 hours. Operating Controls Controls and procedures to prevent hazard to on-site participants or to the off-site public have been successful. Only one person, a test participant, has been injured seriously as a result of the 45 detonations. Outside the Test Site, there has been no instance of hazardous exposure of human beings to radiation from fallout, and no injury from blast waves or the flash of light. There were instances of property damage, such as broken windows, from blast in the Las Vegas area and in St. George -~ mainly confined to eariier series. Cattle and horses grazing within a few miles of the detonation suffered skin deep beta radiation burns on their hides (1952 and 1953 series), with no effect on their breeding value and no effect on the cattle's beef quality. Radiation fallout more than a few miles from the detonation has been in quantities harmless to humans, animals or crops. -8 - COPIED/DOE LANL RC / 7