Date

Oct 1, 1949

Description

Taking into account the “Vermont” findings, the latest assessment by the JNEIC tried to put the best face on things by noting that the test confirmed previous estimates that the Soviets were working on a plutonium bomb (but not mentioning the mistaken estimates of mid-1950 and mid-1953). Nevertheless, the claim that the test occurred in Siberia suggested that acoustic and seismic data, which later indicated that the test had occurred at Semipalatinsk, had not yet been analyzed. Taking into account the plutonium findings, the report estimated that the Soviets had one or possibly two “graphite-moderated production piles in operation since October 1948” [only one pile, operating since July 1948]. On that basis, the committee estimated that the Soviets would have a stockpile of ten weapons by the end of 1949 and 25 by mid-1950, an overestimate because Moscow had only a handful of deliverable weapons in 1951 and did not produce them in quantity until 1953.[18]

Source

CIA FOIA Website

Document published in following posting(s):

Detection of the First Soviet Nuclear Test, September 1949

Sep 9, 2019

Joint Nuclear Energy Intelligence Committee, “Status of the U.S.S. R. Atomic Energy Project: An Extended Estimate for the Joint Staff Plans Group of the Joint Chiefs of Staff,” 1 October 1949, attached to less detailed version of the report, same date, Top Secret