77. Memorandum From the President’s Special Assistant for Science and Technology (Wiesner) to the President’s Special Assistant for National Security Affairs (Bundy)0
SUBJECT
- DOD Study on Atmospheric Testing
I do not believe that there are any critical requirements for nuclear tests in the atmosphere at this time. The material presented in the attached study1 does not change the following summary conclusion on this subject by the Ad Hoc Panel on Nuclear Testing under the chairman-ship of Dr. Wolfgang K. H. Panofsky.
“The range of weapon development tests which can be undertaken would not be seriously impaired if only underground test were permitted. Nevertheless, it should be recognized that the restriction to underground tests would make some tests more difficult and costly. In addition, some weapons effects tests at high altitude of interest to (but on the basis of present knowledge not critical to) the AICBM problem could not be carried out if testing is only permitted underground.”
It should be noted that none of the atmospheric tests discussed in the attached study, with the exception of certain large yield proof tests, could in fact be conducted for some time. The large yield proof tests in question could be conducted in space with some delay and additional cost. Therefore, a decision as to whether or not to initiate atmospheric testing in the near term should weigh the relative importance of the increased speed of weapons development and reduced cost of atmospheric testing against the political problems resulting from fallout associated with atmospheric testing. Aside from the issue of speed and economy, there is not any particular technical pressure for an early decision on atmospheric testing since the important tests for which atmospheric testing would be necessary for technical reasons could not be conducted for some time. Nevertheless, it may be desirable to work out the plans for useful tests that might require long lead-time components.
The limited technical requirements for early resumption of atmospheric testing (apart from increased speed and reduced costs) are best shown by consideration of the specific areas set forth in the attached study. Under Weapons Development (p. 4-5) five areas are listed: (1) [Page 189] large yield clean weapons; (2) [less than 1 line of source text not declassified] (3) [less than 1 line of source text not declassified] (4) proof test of strategic warheads; and (5) AICBM-ICBM systems tests. Only the AICBM-ICBM systems tests inherently need to be conducted in the atmosphere. The other tests are judged to be unsuited for underground testing solely for cost considerations and could be conducted in space as well as in the atmosphere. In none of the cases, except proof tests, could actual devices be ready for test in the near future. This is particularly true in the case of complete systems test of Nike Zeus. It should be noted that military requirements do not now exist for [less than 1 line of source text not declassified]. If such requirements did exist and it was desirable to avoid atmospheric testing, these requirements could be met reasonably well by modifications of existing designs. [1-1/2 lines of source text not declassified] strategic warheads where such increases are of most interest, it would presumably be possible to test such a device underground at a reduced yield of a few hundred kilotons at such time as it would be available for test.
Under Weapons Effects (p. 5-7), four areas are listed in the study: (1) blackout and communications; (2) anti-ICBM effects; (3) atomic demolition munitions; and (4) hardened sites. There is no question that underground testing places significant limitations on the effects data that can be obtained and that important information could be obtained from atmospheric testing. However, the Ad Hoc Panel on Nuclear Testing concluded that additional effects information in these areas is not critical at this time to any of our military systems. In view of the complex nature of the experiments, none of these effects tests could be conducted in the atmosphere in the near future with the exception of the very low military priority area of atomic demolition munitions.
With respect to blackout and communications, there is no question that high altitude tests would be necessary to obtain more quantitative information in this area and that this information would be militarily useful. However, as pointed out in the report of the Ad Hoc Panel, we already have considerable information in this area and know what steps must be taken to assure the operation of our AICBM and communications systems. With respect to AICBM effects, additional information would also certainly be very valuable. However, as also pointed out in the report of the Ad Hoc Panel, a great deal of information is available on this subject and the problem is well understood theoretically. Only recently have serious efforts been made to react to the already available information. In this area, much additional information can probably best be obtained by non-nuclear laboratory tests and by carefully instrumented underground experiments such as the proposed [less than 1 line of source text not declassified]. Nevertheless, on over-all AICBM system test, [Page 190] if desired, would require an atmospheric test. Such a systems evaluation test is some years in the future.
The need for additional information on atomic demolition munitions appears to be of very low priority. Such weapons, which are not very significant in our military posture, can certainly be effectively used on the basis of present effects information. The need to determine the relation between depth of burial and radioactive fallout is more important in determining the method of operation and acceptability of nuclear explosions for peaceful excavation purposes. However, the importance of this issue should be considered separately from military requirements. With regard to hardened sites, a great deal of information is available and more will be obtained from the planned underground Hardhat experiment. While a test of the over-all vulnerability (including possible electromagnetic effects) of a hardened site would involve atmospheric tests, such tests are probably not required if full use is made of available data. If it should be decided to go ahead with such systems evaluation tests, they could not be conducted for some time to come.
With regard to the specific recommendations in the attached paper, I would offer the following comments:
- (1)
- I agree with the recommendation that “the presently planned test program proceed under the assumption that it will be conducted underground during the next year.” As a separate issue, I believe that the tests in question should be carried out underground as quickly as possible, with particular emphasis on priority items, and should not extend over the next year if the time can be shortened. With regard to the recommendation on venting, I agree that the testing policy should not be so conservative as to not permit the possibility of small amounts of gas venting through fissures as occurred in the 15 September 1961 test. This would not only apply undue constraints on the AEC; but also the public relations problem will have been met since gas venting has already occurred and will be shortly announced. However, as long as we are maintaining a posture for public relations purposes of only testing underground, policy should not be relaxed to a point that would permit only partial containment of an explosion such as occurred in 1958 in the Blanca shot which broke the surface and vented several per cent of its fission products directly into the air. From the point of view of public relations, such detonations would probably be looked on as essentially the same as atmospheric testing.
- (2)
- I agree with the recommendation that “exploration and appropriate preparatory steps be taken toward providing an underground test capability for the indefinite future.” This will provide an important future capability.
- (3)
- I am not convinced that it is necessary or even desirable at this time to implement the recommendation that “preparations be made for [Page 191] possible atmospheric tests in the range up to a few tens of kilotons at the Nevada Test Site.” Tests of these small yields can easily be conducted underground. Such tests would satisfy few, if any, of the special test requirements associated with atmospheric testing. The reason for this type of testing would be to accelerate substantially the present test schedule. A decision to undertake such atmospheric tests would appear to be desirable only if it were determined that there would be less adverse world reaction to such fallout tests than to the continuation of our underground tests at a future time when the Soviets may discontinue testing. Unless a definite decision is made at an early date to conduct such small yield tests in the atmosphere, contingency preparations should probably be restricted to long lead-time items not otherwise available in connection with underground tests.
- (4)
- While I do not object to the recommendation to bring the Eniwetok Proving Grounds to a three month readiness posture, I would suggest that before there are any significant expenditures for this purpose an evaluation should be made of the relative costs and timing of space testing. In addition, consideration should be given as to whether the proposed systems tests (i.e., AICBM and ICBM) which could not be conducted in space would in fact be conducted at the Eniwetok Proving Grounds.
- (5)
- I would agree with the recommendation that “the possibility of completely seaborne operations be given some attention” for comparison with the other methods of conducting atmospheric tests.
- (6)
- I agree with the recommendation that “Vela (detection) and Plowshare (peaceful uses) tests should proceed underground.” I do not, however, believe that a final determination should be made at this time as to whether or not Plowshare experiments that are only “partially contained” should be undertaken. Such a decision would clearly depend on the experiment in question and the circumstances existing at the time. I am not aware of any proposal for Vela shots that are only “partially contained.”
- (7)
- I agree with the final recommendation that “… the U.S. should make no public statement foreclosing the possibility of carrying out a limited number of atmospheric nuclear explosions.”
- Source: Kennedy Library, National Security Files, Subjects Series, Nuclear Testing 9/27-10/11/61. Secret.↩
- Document 74.↩