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

39. National Intelligence Estimate¹

NIE 11-2-64

Washington, July 16, 1964.

THE SOVIET ATOMIC ENERGY PROGRAM

The Problem

To evaluate significant recent information and developments in the Soviet Atomic Energy Program and to estimate the probable future course of that program to mid-1974.

Summary and Conclusions

General

1. Since publication of NIE 11-2-63, final evaluations of Soviet nuclear devices tested in 1961 and 1962 and re-evaluations of several earlier devices have led to some changes in the estimate of Soviet nuclear weapon capabilities. While new evidence has led to no changes in the previous estimate of U-235 production, a small upward revision of current and future plutonium-equivalent production has been necessary. The estimate has been extended to cover a ten-year period to mid-1974.

Soviet Nuclear-Powered Submarine Program²

2. Three basic classes of nuclear-powered submarines are known to have been constructed in the USSR and identified in an operational status. (See Table IV).³ A number of these submarines are probably undergoing modifications. The performance of the Lenin and several of the nuclear submarines during 1963 indicates that the Soviets have probably improved the reliability of their naval nuclear propulsion system. We believe, however, that there is a need for further improvement in their nuclear propulsion technology and operational reliability. (Paras. 17-18)

Fissionable Materials Production

Plutonium-Equivalent

3. There are three plutonium production sites in the USSR; these are located at Kyshtym in the Urals, and near Tomsk and Krasnoyarsk in Central Siberia. [4-1/2 lines of source text not declassified] (Para. 21)

4. [7-1/2 lines of source text not declassified](Paras. 25-26)

5. Future production estimates have taken into consideration Khrushchev’s statement in April 1964 that the Soviet Government had decided “to discontinue now the construction of two new, big, atomic reactors for the production of plutonium.”⁴ We have no basis, at present, for ascertaining whether or not such construction has been discontinued. The spread shown in Table VI for the years 1967-74 represents estimates with and without continuing construction of new reactor facilities. It is estimated that even if reactor construction is discontinued, improvements in reactor operation will lead to increases in future annual plutonium-equivalent production rates. (Paras. 27-28)

U-235 Production

6. There are four gaseous diffusion isotope separation complexes in the USSR: one at Verkh-Neyvinsk in the Urals, one north of Tomsk in Central Siberia, a third at Angarsk in the Lake Baykal region, and a fourth which started operation recently, north of Zaozerniy near Krasnoyarsk. Consideration of all available information leads to a U-235 production estimate (see Table VI) which is essentially the same as that shown in NIE 11-2-63. (Paras. 29-32)

7. We estimate that the probable Soviet cumulative U-235 production for mid-1964 is 170,000 kilograms and that it is unlikely that actual cumulative U-235 production is less than 100,000 or more than 220,000 kilograms.⁵ There is no valid means, short of on-site inspection of determining whether or not or by how much the USSR will carry out the announcement by Khrushchev that the USSR has decided “… in the next several years to reduce substantially the production of U-235 for nuclear weapons …,” therefore, a cut-back has not been assumed in the projected estimate. We estimate that by 1967 the [1-1/2 lines of source text not declassified] will increase the Soviet U-235 production capacity 60 percent over their mid-1964 production rate. (Paras. 30-32)

Nuclear Weapons

Weapon Improvements from 1961-1962 Tests

8. The Soviets significantly improved their fission and thermonuclear weapon capabilities as a result of the 1961-62 test series. However, the status of Soviet nuclear weapon technology, while highly sophisticated and apparently adequate for their present needs, is such that substantial advances can still be made through further development and testing. We believe that the Soviets are continuing an active weapon development program. They will certainly have a continuing requirement to test at a greater rate⁶ than has been evident since the Test Ban Treaty was initialed in July 1963. (Paras. 42-48, 50-57 and 64)

9. Fission Weapons. By 1958, the Soviets had developed implosion devices encompassing a variety of yields and physical dimensions and employing boosting techniques in some cases. The 1961-62 test series provided the Soviets with improved fission weapon capabilities. [2 lines of source text not declassified] However, a large number of new devices were tested without employment of boosting. This perhaps indicates that the Soviets will limit their employment of boosting, thus, in their unboosted weapons gaining simplicity and a reduced requirement for tritium at the cost of some increases in vulnerability, fissionable materials, and size, and perhaps decreased yield. [2-1/2 lines of source text not declassified] However, possible undetected tests and [less than 1 line of source text not declassified]might have provided the Soviets with still smaller low-yield weapons. (Paras. 41-45)

10. Thermonuclear Developments. By 1958 the Soviets had tested a variety of thermonuclear devices [2 lines of source text not declassified]. In 1961 and 1962, the Soviets greatly improved the performance of their thermonuclear weapons and extended their yield experience. [10 lines of source text not declassified]

11. [10-1/2 lines of source text not declassified]

Future Weapon Development and Testing

12. We have detected only three Soviet tests in the twelve months since the initialing of the Test Ban Treaty in July 1963. There are undoubtedly a variety of useful tests the Soviets could now conduct underground both for research and development and for military purposes. We have no evidence that they have conducted tests banned by the Treaty and do not believe they will resort to such tests so long as the options of underground testing and formal treaty withdrawal are open to them. (Para. 65)

13. It is certain that the Soviet weapons laboratories have remained active and are creating new test requirements. The potential improvements obtainable through underground testing together with the high rate of US underground testing [less than 1 line of source text not declassified] between 1 August 1963 and 1 July 1964—must be generating considerable pressure on the Soviet leadership for a more vigorous test program than has been conducted to date. We do not believe, however, that research, development and military requirements alone are now so pressing as to necessitate withdrawal from the Treaty or are likely to become so in the near term. Hence, we believe that political factors will be the major consideration in reaching a decision whether or not to withdraw. If such a decision is made by the Soviets, atmospheric testing by the French or Chinese Communists might provide the pretext. (Para. 66)

14. If the Soviets embark on a reasonably extensive underground testing program involving yields up to about 200 KT, they could achieve, during the period of this estimate, [4 lines of source text not declassified]. Improvements in Soviet low-yield devices which could occur during the period of this estimate are more likely to emphasize the development of small-diameter [less than 1 line of source text not declassified]warheads rather than [6-1/2 lines of source text not declassified].

15. Underground testing and simulation techniques would permit the acquisition of a limited amount of weapon effects data, including the effect of ground shock upon hardened underground structure, the effects of nuclear radiation upon materials or systems components, and [less than 1 line of source text not declassified]. Other effects data related to high-altitude effects and the full effects of electromagnetic pulse could not be obtained through underground testing. (Paras. 72-74)

[Here follow Part I. Soviet Nuclear-Powered Submarine Program; Part II. Fissionable Materials Production; Part III. Soviet Nuclear Weapons Program; and Annex A. Evaluation of Soviet Nuclear Tests (29 August 1949-6 June 1964.]

1. Source: Johnson Library, National Security File, National Intelligence Estimates, 11-64, USSR, Box 3. Top Secret; Restricted Data. According to a note on the cover sheet: “This estimate consists of an updating of those subjects in NIE 11-2-63 about which significant new information has become available, and which merit a restatement. It includes topics under the following main headings from NIE 11-2-63, ‘The Soviet Atomic Energy Program,’ dated 2 July 1963: Nuclear Reactor Program—Marine Nuclear Propulsion Systems; Fissionable Materials Production; Soviet Nuclear Weapons Program. The reader should refer to NIE 11-2-63 for information on other details of the Soviet atomic energy program.” NIE 11-2-63 is ibid., National Security File, National Intelligence Estimates, 11-63,USSR, Box 1)
2. For the estimated number of Soviet submarines, see National Intelligence Estimate 11-14-63, dated 8 January 1964. [Footnote in the source text. NIE 11-14-63 is ibid.]
3. None of the six tables is printed.
4. Quoted from Khrushchev’s statement, April 20, 1964. (Documents on Disarmament, 1964, p. 168)
5. See page 21 for the view of the Assistant Chief of Naval Operations (Intelligence), Department of the Navy. [Footnote in the source text.]
6. As of 1 July 1964 three tests had been detected. [Footnote in the source text.]