fk conducting the tests including many long delays until weather conditions were favorable. The permissible sectors and distances around NTS for deposition of relatively heavy fallout are limited, thus requiring a continuation of strict criteria in the timing of the detonations. The use of higher towers, surfaced areas around ground zero, and the possible use of balloons for suspending the nuclear devices as well as other methods of detonation under consideration, should assist in reducing the fallout outside the Nevada Test Site. 5. Unlike accumulation of doses by small increments (as in an atomic energy installation) providing opportunity for preventive action as established limits are approached, the occurrence of fallout on a community can be a quanta event and once it has occurred certain exposures will ensue unless rather drastic action such as evacuation is taken. Therefore, operational requirements would indicate a relatively large radiation exposure guide for a Single year. The criterion of 3.9 roentgens per year has been in effect, widely reported by the Atomic Energy Commission and used in educational programs with the people around the NTS. Therefore, in the absence of any compelling reason to the contrary, it is’ recommended that this criterion be retained. As with the criterion of 10 roentgens in 10 years, it should be made clear that 3.9 roentgens per year is an operational puide, and exposures somewhat in excess of this should not be construed as being hazardous, 6, The method of estimating the gamma doses shall be according to AEC 141/15 (as possibly amended, following re~ evaluation of the relevant data), radiological safety criteria and procedures for protecting the public during weapons testing at the Nevada Test Site, -5- Appendix "a"

Select target paragraph3