Chernobyl Nuclear Power Plant CIA Files - Paperless Archives

6 TOP SECRET
DISCUSSION
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I. THE NUCLEAR WEAPONS PROGRAM
A. The Nuclear Test Program
1. The Soviets have continued underground
testing during the past 2 years, with 18 tests
detected in 1969 and 13 in 1970. These magnitudes
are about the same as those for the
previous 6 years. By the end of May 1971,
an overall total of 290 nuclear tests had been
detected, 186 before the Limited Test Ban
Treaty (LTBT) went into effect in 1963, and
104 thereafter. At least 15 of the underground
tests were part of the Soviet program
for peaceful uses. {
]
2. Underground weapons-related tests have
averaged about 1 per month since 1963. These
1 See Annex A for a listing of Soviet underground
tests since the L TBT went into effect. See Section V
for a discussion of the tests for peaceful uses.
tests have ranged in yield from less than
1 kiloton (let) to up to 3 to 6 megatons
(MT). Most if not all of the 18 tests with
yields above 100 kt were probably for the
development of thermonuclear weapons. Of
the remaining tests, some were probably for
fission weapon development, and some were
tests of weapons effects[
3. Most Soviet underground tests occur in
either the Semipalatinsk area of Kazakhstan
or in the Novaya Zemlya area of the western
Arctic. Since 1963, we know of a total of 15
underground detonations which have taken
place in other areas. In October 1970, the
Soviets conducted their largest underground
test at Novaya Zemlya, which yielded an esti-
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