1. Ambassador Dobrynin, at his
initiative, called on Assistant Secretary Hillenbrand on January 6 to present the following oral
On December 16, 17 and 18, 1970, the United States carried out four
underground nuclear explosions as a result of which there was a release
of radioactive products into the atmosphere. According to reports, a
noticeable increase in radiation occurred in the area of the explosion
and at considerable distance from it.
The Soviet side could not but pay attention to the lack of an official
evaluation of the possibility of the radioactive cloud going outside the
national borders of the
As is known, the Treaty banning nuclear weapon tests in the atmosphere,
in outer space and under water prohibits a signatory from carrying out a
nuclear test, “if such explosion causes radioactive debris to be present
outside the territorial limits of the State.”
Drawing attention to the fact of release into the atmosphere of a large
quantity of radioactive products as a result of a nuclear explosion on
December 18, the Soviet side expects that necessary explanations will be
given in the light of the Treaty which banned nuclear explosions causing
radioactive debris to be present outside territorial limits.
Competent Soviet authorities will naturally watch the radioactive cloud
that has developed and, if the analyses of the debris of this cloud
reveal the presence of radioactive products, then the Soviet side
reserves the right to return to this question. END QUOTE
2. Hillenbrand said that he had
not received a full report of the tests to which Dobrynin referred. Any pertinent
information relating to the matter raised in the Soviet statement would
be brought to the attention of the Soviet Government.
3. Hillenbrand then said that he
would like to call the Ambassador's attention to Soviet nuclear
explosions of October 14 and December 17, 1970 from which we had
collected radioactive material outside the borders of the USSR. In this connection he handed
Dobrynin a piece of paper
containing the following statement:
The United States collected outside of the Soviet Union radioactive
material directly associated with the Soviet nuclear explosions of
October 14 and December 17, 1970.
In view of Paragraph 1(b) of Article I of the Treaty Banning Nuclear
Weapon Tests in the Atmosphere, in Outer Space, and Under Water, the Government of the United
States wishes to draw the attention of the Government of the Soviet
Union to this matter, and to the importance of due precautions to insure
compliance with that Treaty. The United States Government would welcome
any pertinent information the Soviet Government could make available
about these events. END QUOTE
Hillenbrand added that both
sides no doubt agree that it is in their interests to observe the
Limited Test Ban Treaty as rigorously as possible. In this light, it is
useful to exchange information when questions arise from either side. To
the degree possible, of course, both should seek to avoid explosions
which may raise questions, although it is recognized that these
sometimes inadvertently and regrettably occur.
4. Dobrynin said he would pass the
U.S. statement to his government and convey any information given to him
in response to the U.S. request for any pertinent information.
5. FYI. As has been practice in past we
do not intend to publicize nature of this exchange.
1 Source: National Archives,
RG 59, Central Files 1970–1973,
DEF 18–8 US. Confidential. It was
repeated to AEC. Drafted by Dubs
(EUR/SOV); cleared by Davies (EUR) and in PM, SCI, ACDA, and AEC; and
approved by Hillenbrand.