1960s "Nth Country Experiment" Foreshadows Today's
Concerns Over the Ease of Nuclear Proliferation
July 1, 2003
William Burr, editor
Recent issues of the Bulletin of the Atomic Scientists
and the Guardian (UK) (Note 1)
describe a fascinating experiment, sponsored by Lawrence
Radiation Laboratory during the mid-1960s, to determine
whether a non-nuclear power could develop a nuclear weapons
capability more or less from scratch, without access to
classified information. For U.S. government officials
this was not an academic exercise; since the mid-to-late
1950s, U.S. policymakers, intelligence analysts, and policy-oriented
academics had been thinking and writing about the "Nth country
problem"--the possibility that some undetermined number
of countries would develop nuclear weapons capabilities.
The problem of nuclear proliferation, as it eventually became
known, provoked concern that the addition of new nuclear-armed
states would create a more unstable and perilous world.
For example, during a 1963 press conference, President John
F. Kennedy suggested that the possibility of a world, during
the 1970s, with 15 or 20 nuclear powers, posed the "greatest
possible danger and hazard." (Note 2)
To better gauge the threat of nuclear proliferation, administrators
at Lawrence Radiation Laboratory wanted to determine what
it would it would take for a single-minded Nth country to
build a bomb. The lab hired two newly-minted physicists,
David Dobson and Robert Selden, with no access to or knowledge
of classified information, to "produce a credible nuclear
weapons design." Although Dobson and Selden lacked
access to classified information, they knew, just as every
would-be nuclear proliferant has known since August 1945,
the most important nuclear "secret" of all: that it is possible
to design and produce nuclear weapons. As Manhattan
project director General Leslie Groves had testified in
1945, "the big secret … that the thing went off …
told more to the world and to the physicists and scientists
of the world than any other thing that could be told to
them." (Note 3) The two
scientists received "Q" clearances for nuclear weapons design
information because any information that they developed
on nuclear design would, under the law, be considered secret
and "born classified." After three "man-years", the
two physicists had produced a "credible" design for an implosion
nuclear weapon that would be triggered by a plutonium pit.
According to the articles, which are based on interviews
with the participants, the experiment was a success.
The amateur bomb designers learned that they had produced
a plan for a device that, if constructed and tested, would
have as much explosive force as the weapon that had devastated
Hiroshima in August 1945.
Both the Bulletin and the Guardian articles draw on the
"Summary Report of the Nth Country Experiment," edited
by Lawrence physicist W. J. Frank in March 1967. The Energy
Department partly declassified this report in 1995
in response to a FOIA request by the National Security Archive.
The document is heavily excised; for example, a bibliography
of the unclassified publications that the designers read
during the experiment is completely withheld. In addition,
the Energy Department excised specific conclusions about
the practicability of the design. Plainly, the Department
of Energy's reviewers did not want to release information
that would increase anyone's confidence that they could
design and develop their own nuclear weapons. While
access to fissile materials remains the most significant
barrier to the proliferation of nuclear weapons, at a time
when Al Qaeda is racing to get the bomb it is difficult
to find fault with the judgment that the release of nuclear
weapons design information requires the utmost caution.
1. Dan Stober, "No Experience Necessary," The Bulletin
of the Atomic Scientists, May-June 2003, at <http://www.thebulletin.org/issues/2003/ma03/ma03stober.html>,
and Oliver Burkeman, "How Two Students Built an A-Bomb,"
Guardian, 24 June 2003, at <http://www.guardian.co.uk/g2/story/0,3604,983646,00.html>.
Unfortunately, the article in The Guardian shows
some confusion about the administration of the U.S. nuclear
weapons labs by claiming that the Nth Country Experiment
was a "U.S. Army" project. Although the U.S.
nuclear labs had significant military missions, after World
War II, Los Alamos laboratory and Lawrence Radiation Laboratory,
where the Nth Country experiment took place, were projects
of the civilian Atomic Energy Commission and managed by
2. Press Conference, 21 March 1963, Public
Papers of the President John F. Kennedy, 1963 (Washington,
D.C., Government Printing Office, 1964), p. 280
3. As quoted in Arvin Quist, Security
Classification of Information: Volume I. Introduction, History
and Adverse Impacts (Oak Ridge, Tennessee: Martin Marietta
Energy Systems, Inc., September 1989), p. 63.