ATTACHMENT 3 Memorandum titled "Detailed Explanation of AFSWP Comments on Feasibility of Human Volunteer Program" (undated) (Best Copies Available) Annex "A" to 2nd Indorsement Detailed Explanation of AFSWP Comments On Feasibility of Human Volunteer Progress (U) 1. General. The comments contained in paragraph 2 of the 2nd Indorsement to the basic letter, and explained in detail in paragraphs 2 and 3 below, are based on the assumptions that the nature of the experiment proposed would be consistent with Army policy, and that authority to conduct such an experiment would be granted by those responsible. It is believed, however, that in weighing the validity of these assumptions the following should be considered: a. In order to gain scientific data of value by the use of human volunteers, these volunteers would have to be exposed to successively higher levels of the various effects (blast, thermal radiation, and nuclear radiation) singly and in combination. It is evident that the injury threshold cannot be determined without eventually exceeding it. b. In particular, it is significant that the long range effect on the human system of sub-lethal doses of nuclear radiation is an unknown field. Exposure of volunteers to doses higher than those now thought safe may not produce immediate deleterious effects; but may result in numerous complaints from relatives, claim against the Government, and unfavorable public opinion, in the event that deaths and incapacitations occur with the passage of time. 2. Future Nevada Tests. The AFSWP feels that the nature of the experiment proposed nd the rules governing tests at the Nevada Test Site make it highly improbable that any more useful data could be obtained at Nevada than has already been obtained. The nature of the experiment, exposure of humans, makes the risk due to probable error of a delivery system unacceptable. Therefore, the maximum yield which could be used at Nevada, under Atomic Energy Commission rules, would be a 50 XT weapon on a 500-foot tower. It is assumed that to simulate realistic field conditions, only a high neutron flux device would be considered. The following table, compiled from TW 23-200, 1 June 1955, above for 2, 3, 4, 5, and 6 psi at what ranges these overpressures would occur, and what the values of dynamic pressure, thermal energy, and nuclear radiation would be at these ranges. Range Overpressure Dynamic Thermal Energy Initial Carma Same in (yds) (psi) Pressure In Open Plus Neutron Foxholes (psi) (cal/cm2) In Open (REM) (REM) 3500 2 0.1 9.6 1.05 0.12 2620 3 0.3 18.0 16.7 2.44 2140 4 0.5 28.8 95.0 15.7 1900 5 0.6 36.0 267. 46.7 1620 6 0.9 52.2 880. 168. Reliability +10% + 25% + 20% + 50% + 50% - - - - - Annex "A: to 2nd Indorsement (Contd.) From the above it seems highly improbable that those charged with the responsibility in the event of injury or death of personnel would permit an exposure in the open closer than 2,620 yards, or in foxholes closer than 2.140 yards. It is even dubious that these extremes would be permitted. In DESERT ROCK V, eight volunteer officers were exposed in a trench at 2,000 yards from ground zero on Shot 7. From TM 23-200, 1 June 1955, it is estimated that they received ¬ psi (+ 10%) overpressure. Although film badges on the volunteers indicated an average gram dose of 1¬ roentgens, best information available suggests that the true dose was probably 24 ILLEGIBLE initial gamma plus neutron radiation. It is also noted that this shot higher yield than was anticipated; and it is considered doubtful that exposure to this level of radiation would have been permitted had it been anticipated in advance. a. The AFSWP considers that the physical nature of the Pacific Proving Grounds and the type of shots usually conducted there are such that the feasibility of conducting a human volunteer program in the Pacific sometime after REDWING, as proposed by COWARC, is extremely doubtful. Again, the probable error of a delivery system, and the unacceptable attendant risk, rules out an air burst. The danger of drowning the human volunteers makes a barge shot infeasible. Therefore, the test would have to be limited to a 300-foot tower shot with either a test device or a standard weapon. The uncertainty of the yields of test would require that the volunteers be positioned for the maximum probable yield, even though it has a low probability of occurring, rather than the expected or design yield. A consideration of these yields for a few purposed REDWING shots, which may be considered typical, illustrates the magnitude of this problem: Shot Probable Yield Positioning Yield (Design) (Maximum Probable) CHERCXXX MURCH ZUHI FLATHEAD DELETED NAVAHO APACHE MOHAWK Take for example the most favorable of these, the HURCH shot. If human volunteers were to be pleased to investigate 5 psi, the next psi level above that which has already been tested, they would have to be positioned on the assumption that the yield would go ILLEGIBLE. Then if the yield went ILLEGIBLE as designed, the volunteers would be subjected to less than 4 psi; and the experiment would have failed to prove anything new. For the other shots in the above table the discrepancies would be even greater. Thus the only alternative would be to use a standard stockpile weapon with the attendant problem of positioning the volunteers for at least the + ILLEGIBLE probable error in the yield of the stockpile weapon at the risk of having it go ILLEGIBLE less than the design yield. 2 Annex "A" to 2nd Indorsement (Contd.) The use of stockpile weapon in itself presents a problem, since the test shorts at the Pacific Proving Grounds are almost exclusively experimental devices. Hence using a stockpile weapon means designing a shot primarily for the human volunteer experiment. This could not be done as suggested in paragraph 3 of the basic COWARC letter: "... with negligible expense, preparation time, and interference with test programs." The following table illustrates the wide variation or ranges involved and emphasizes still another difficulty encountered in conducting such a test at the Pacific Proving Grounds, even with standard stockpile weapons, and that is the lack of real restate. The table is based on the assumption that the Test Director would allow humans to be exposed to 25 ram initial gamma plus neutron dose and 60 cal/cm2 thermal energy with the entire body protected by winter uniform (4 layer) or its equivalent. These are levels much higher than have heretofore been allowed; and it is doubtful that these levels would be permitted. Permission to exceed them would almost certainly not be obtained. The table shows the maximum dynamic pressure and overpressure to which persons in the open and in foxholes, respectively, could be exposed without exceeding nuclear or thermal radiation tolerances for standard yields ILLEGIBLE and the range to which the 5 psi level would extend for each weapon. Yield Maximum Dynamic Range Maximum Range Range Pressure (yds) Overpressure (yds) at 5 psi (psi) (psi) (yds) DELETED * Note that human eardrum rupture may be expected to take place between 7-15 psi. The ranges corresponding to the pressure levels of interest are such that it would frequently be impossible to find a piece of land at the desired range on which to place the volunteers. Another significant problem with these yields on a 500-foot tower is the fall-out hazard. From the above it is evident that an experiment which would meet the requirements of safety, fit the available real estate, and still yield useful results would be difficult indeed to design. Distribution: (6 cys) Cy 1A - Chief, R&D, OCS, D/A, Wash. 25, D.C. Cy 2A - BRL (Attn: Mr. W.J. Taylor) Cy 3A - SWPEF-2 Cy 4A - A.G. Cys 5 & 6A - SWPEF-2, Read File 3