Attachment 2-C OFFICE OF THE CHIEF OF STAFF WASHINGTON 25, D.C. CS 471.5 (15 Dec 53)3 February 1953 MEMORANDUM FOR: THE CHIEF OF STAFF, U.S. ARMY SUBJECT: Positioning of Troops at Atomic Explosions 1. Recognizing that the position of troops with respect to ground zero at previous tests of atomic weapons was unduly conservative (7,000 yards at last test), you directed the Staff to study the possibility of decreasing this distance. The results of this study are presented in the attached summary sheet. 2. You will note that the Staff recommends selected individuals, presumably experience in atomic weapons effects, should not be permitted to be in trenches closer to ground zero of a 20 K.T. burst than 3,2000 yards. Existing doctrine would lead a ground commander to believe that his troops would be safe in trenches as close as 1,5000 yards from ground zero. 3. In view of the Staff conservatism, yet recognizing the need to prove or change our doctrine, General Lemoitzer discussed this matter in conference with General Nichols, General Roper, General Cooney, and Colonel Hertford. All of whom recommended that while these criteria should be used for the exposure of a large numbers of troops, we should give the maneuver commander discretionary authority to use a small group of selected individuals to more definitely prove our doctrine. Accordingly, it was agreed that the selected group (on tower shots only) should be permitted to be exposed to 10 pounds per square inch over-pressure (which means 8 PSI at ground surface), nuclear radiation up to 10 roentgens per test with not more than 25 for the whole series, and thermal radiation at one calorie. The Surgeon General has agreed that it is highly improbable that such exposure will result in any injury to these selected individuals. 4. It is recommended you approve the safety criteria established in the attached summary sheet as amended by the recommended grating of discretionary authority to the maneuver commander.