56. Memorandum From the Assistant Director for Scientific Intelligence of the Central Intelligence Agency (Chamberlain) to the Deputy Director of Central Intelligence (Carter)/1/

Washington, October 15, 1964.

/1/Source: Central Intelligence Agency, DCI (McCone) Files: Job 80-B01676R, DDCI Trip to the Far East, 17-31 October 1964. Top Secret. Concurred in by the Deputy Director for Science and Technology, with the notation that a memorandum to holders of the estimate was planned for the following week. A paper entitled "Indications Relating to a Chinese Communist Nuclear Test in the Near Future," neither signed nor dated, is attached to the source text, along with a second memorandum of October 15 from Chamberlain to Carter entitled "The Chinese Atomic Energy Program."

SUBJECT
Estimated Imminence of a Chinese Nuclear Test

1. This memorandum is for your information.

2. In a Special National Intelligence Estimate issued in August 1964/2/ it was concluded that, on balance, a Chinese nuclear test probably would not occur before the end of 1964. At that time available information indicated that the Chinese nuclear test site near Lop Nor was under active construction and could be ready for a nuclear test by about October 1964. On the other hand, continuing construction in September 1963 at the only known Chinese plutonium production site indicated a probable startup of the reactor at that site in early 1964. This in turn indicated a date around mid-1965 for first availability of sufficient plutonium for a nuclear test. Although neither the possibility of an earlier startup of this plant nor the existence of an unidentified plutonium production facility could be wholly discounted, it was felt unlikely that plutonium would be available in 1964. The U-235 plant at Lanchou is only partially complete and thus could not contribute fissionable material for a nuclear test in the near future.

/2/Document 43.

3. More recent information on the Lop Nor test site has confirmed the earlier estimate of its probable readiness date. Preparations for a test were essentially completed at the Lop Nor nuclear test site by October 1964. Included in these preparations is a 340 foot shot tower that was installed prior to April 1964 and is now surrounded by a double fence. Arrays for instrument emplacement are located around the tower. These include arcs at 9,800, 16,000, 23,000 and 33,000 feet respectively and a number of radial lines from the tower with bunkers and platforms emplaced along the lines. Two small towers, approximately 50 feet high, are located on the arc at 9,800 feet from the shot tower and at 905 from each other. Available information does not permit determination of whether or not instruments have actually been emplaced on the platforms and towers. The high priority apparently given to the completion of site construction suggests that a test is scheduled in the fairly near future since it would not be desirable to establish the parameters of an initial nuclear experiment much in advance of the test.

4. A high level of flight activity to and from the area was noted throughout this very active construction period. The activity halted in September 1963 when the site was essentially complete. Subsequent resumption of this activity in late September may reflect final preparations for testing.

5. A restudy of the Pao-t'ou reactor site indicates that adequate primary and backup electric power circuits for reactor operation had been installed by March 1963. Thus, our confidence has been reduced in the August 1964 judgment that the reactor probably did not start operation until early 1964. Another prospect for a fissionable material supply is a facility in a large complex near Chih-Chin-Hsia (Yumen) which might contain a small operational reactor, but this identification is uncertain.

6. We no longer believe that evidence on plutonium availability justifies the on-balance judgment reached in August 1964. We believe the Lop Nor evidence indicates that a test could occur at any time. In any case we believe a test will occur sometime within the next six to eight months.

Ernest J. Zellmer/3/

/3/Zellmer signed for Chamberlain above Chamberlain's typed signature.