Foreign Relations of the United States, 1964–1968, Volume XI, Arms Control and Disarmament

79. National Intelligence Estimate¹

NIE 11-2-65

Washington, May 19, 1965.

THE SOVIET ATOMIC ENERGY PROGRAM

The Problem

To estimate the current status and probable future course of the Soviet atomic energy program over the next five to ten years.

Conclusions

A. In a nuclear test program of more than 15 years duration, the USSR has developed nuclear weapons in a variety of designs and sizes which we believe have yields ranging from fractions of a kiloton up to 100 megatons. Soviet weapons technology has differed from that of the US in certain respects. In thermonuclear weapons, the Soviets have emphasized the development of multimegaton devices rather than relatively small, light weight lower yield weapons, [1-1/2 lines of source text not declassified]. (Paras. 10-14, 16-17, Table III)

B. In fission weapons the Soviet program has been directed toward development of reliable, efficient, and economical devices. They have emphasized development of unboosted devices but they have also developed some high-performance boosted devices, probably in order to achieve reductions in size and weight. [2 lines of source text not declassified] Our evidence is insufficient to determine whether the Soviets decided not to pursue development of lightweight fission weapons or whether the apparent lack of development in this area is because of our failure to detect the evidence of such a program. However, there have been a number of Soviet tests on which we have little or no data and the Soviets have probably developed and stockpiled a number of fission weapons which we have not identified. (Paras. 18-20, 22-23, Table IV)

C. We have detected 11 Soviet underground tests since the test ban treaty took effect in 1963. We believe that most of these were related to thermonuclear rather than fission weapons, possibly directed toward development of [5-1/2 lines of source text not declassified]. The rate of underground testing detected to date does not indicate that the Soviets have made an extensive effort to improve their fission weapon technology. (Paras. 15, 21)

D. The Soviets are continuing an active weapon development program which is almost certainly creating new test requirements. This, together with the active US program of underground testing is probably generating considerable pressures for a vigorous test program. The pace of Soviet underground testing will probably increase. However, we do not believe that research, development, and military requirements will become so pressing as to cause the Soviets to withdraw from the treaty in the near term. (Para. 31)

E. In thermonuclear weapon technology, an area in which the Soviets could make significant advances—the submegaton and low megaton yield range—is susceptible to improvement by underground testing. Future improvement in fission devices could be in the direction of further development of small diameter [less than 1 line of source text not declassified] warheads. The Soviets could also obtain a limited amount of data on weapons effects by underground testing, but one of their strong-est requirements in this area—effects data on high-altitude nuclear explosions—could be met only by atmospheric testing. (Paras. 32-36)

F. The Soviets are continuing to expand their facilities for the production of fissionable materials. Our estimates indicate that by 1975 Soviet [1-1/2 lines of source text not declassified] U-235 production will increase by more than one-third, resulting in nearly a four-fold increase in cumulative production by that date. These estimates are subject to wide margins of error. Nevertheless, a significant expansion of these facilities has continued despite Khrushchev’s statement to the contrary in April 1964.² (Paras. 1-9, Tables I and II)

G. In industrial and military applications of power and propulsion reactors, the Soviet program has been characterized by certain technological weaknesses. Inadequate developmental testing has tended to degrade operational reliability, chemical engineering has lagged, and capabilities in stainless steel technology has been notably weak. As a result, the Soviets encountered major problems with their first marine propulsion system. This system has been considerably modified and improved and probably will give satisfactory performance in the newer ships and submarines. But the Soviets are still several years behind the US in marine propulsion technology. Technological difficulties, together with economic constraints, have also slowed the Soviet nuclear electric power program. The Soviets are now embarked upon a program of expansion which incorporates many of the power reactor concepts under development in the West, but we doubt that they will achieve their planned expansion to a 2,000 megawatt generating capacity by 1970. (Paras. 39-45)

H. Soviet research reactors appear to be adequate in quality and quantity to meet the needs of the atomic energy program, although nuclear research has probably been hampered somewhat by deficiencies in instrumentation and by the limited availability of large fast computers. Reactor research seems directed toward power and propulsion application with emphasis on containment materials, coolants, moderators, and fuels capable of withstanding high irradiation levels and temperatures. (Paras. 37-38)

I. More advanced research in thermoelectricity and thermionics will probably find application in space power supplies, which will eventually permit the use of electric propulsion systems in space. The Soviet program of research on controlled thermonuclear reactions is the world’s largest, and Soviet scientists have made major advances in plasma physics. We do not believe, however, that the USSR will achieve a controlled fusion reactor in the next ten years. (Paras. 45-51)

[Here follow a four-part “Discussion,” entitled “Soviet Production of Nuclear Materials,” “The Nuclear Weapons Program,” “The Nuclear Reactor Program,” and “International Activities,” and a three-part Annex.]

1. Source: Johnson Library, National Security File, National Intelligence Estimates, 11-65, U.S.S.R., Box 3. Top Secret; Restricted Data. Submitted by the Director of Central Intelligence and concurred in by the U.S. Intelligence Board.
2. For the views of the Assistant Chief of Naval Operations (Intelligence), Department of the Navy, see the footnote to paragraph 4, page 5. [Footnote in the source text. The cited text and footnote are not printed.]