Interviews with Federal Civil Defense Administration observers, and with Nevada Test Organization participating personnel, will be arranged on request if and when practicable. Personnel conducting the tests are extremely busy, and it is only rarely that they can be available except at formal occasions such as pre-series briefings. About 60 persons from civil defense organizations are being invited by the Federal Civil Defense Administration to witness each of the nine _ tests to which uncleared observers are admitted, In addition military and/or civil defense observers from 47 foreign nations are being invited to witness test shots. The Federal Civil Defense Administration has invited civil defense representatives from the North Atlantic Treaty Organization to witness specified shots, The Department of Defense has invited military observers from member nations of NATO, the Southeast Asia Treaty Organization, the Inter-American Defense Board, -the Permanent Joint Board of Defense (Canada-U.S.), and ‘the Baghdad Pact. All of the 47 nations invited to send either military or civil defense observers have also been informed that news media representatives from these countries may be present to report at least one of the series. open to reporting by United States media. The purpose of inviting the attendance of observers and news media reporters from these 47 nations is to familiarize them with United States nuclear weapons testing policies and operations, especially safety procedures, 10. BALLOONS, TUNNELS AND ROCKETS Three previously unused placements of nuclear devices are being employed in the 1957 series. Several balloon shots have been announced, One shot will be detonated in a deep underground tunnel, and there will be an air-to-air rocket detonation of a nuclear device. A primary purpose for suspending devices on balloons is the reduction of nearby radioactive fallout. It is hoped that a device fired deep underground will eliminate essentially all airborne fallout. The ideal positioning from the single viewpoint of the scientist would be, for most shots, on the surface. This would greatlysimplify installation of data recording equipment and avoid climbs up 500-foot towers. ~~ . Because such shots must be very seriously limited as to yield permitted because of resultant fallout, almost all Nevada devices are placed high above the ground. In the past they have been detonated - on towers up to 500 feet, or dropped from aircraft to explode well above ground level. No air. drops are scheduled during the current series. offi In this series there will be one tower of 700 feet - a long tch for some instrumentation. ~ "zp/D0E vy RG . 13 - 0 -