12 © The Containment of Underground Nuclear Explosions
The test was followed 2 weeks later by the 500
kiloton explosion ‘‘King,’’ the largest fission weapon
ever tested.
At the NevadaTest Site, low-yield fission devices
continued to be tested. Tests were conducted with
nuclear bombs dropped from planes, shot from
cannons, placed on top of towers, and suspended
from balloons. The tests were designed both to
develop new weapons and to learn the effects of
nuclear explosions on civilian and military structures. Some tests were conducted in conjunction
with military exercises to prepare soldiers for what
was then termed ‘‘the atomicbattlefield.”
{n the Pacific, the next tests of thermonuclear
(hydrogen) bombs were conducted under ‘*‘Operation Castle,’’ a series of six tests detonated on the
Bikini Atoll in 1954. The first test, *‘Bravo,’” was
expected to have a yield of about 6,000 kilotons. The
actual yield, however, was 15,000 kilotons—over
twice what was expected.® The radioactive fallout
covered an area larger than anticipated and because
of a faulty weather prediction,the fallout pattern was
more easterly than expected. A Japanese fishing
boat, which had accidentally wandered into the
restricted zone without being detected by the Task
Force, was showered with fallout. When the fishing
boat docked in Japan, 23 crew members had
radiation sickness. The radio operator died of
infectious hepatitis, probably because of the large
numberof required blood transfusions.’ The faulty
fallout prediction also led to the overexposure of the
inhabitants of two of the Marshall Islands 100 miles
to the East. In a similar though less severe accident,
radioactive rain from a Soviet thermonuclear testfell
on Japan.’ These accidents began to focus world-
wide attention on the increased level of nuclear
testing and the dangers ofradioactive fallout. Public
opposition to atmospheric testing would continue to
mount as knowledge of the effects of radiation
increased and it became apparentthat no region of
the world was untouched.?
Attempts to negotiate a ban on nuclear testing
began at the United Nations Disarmament Confer-
ence in May 1955. For the next several years efforts
to obtain a test ban were blocked as agreements in
nuclear testing were linked to progress in other arms
control agreements and as differences over verification requirements remained unresolved. In 1958,
President Eisenhower and Soviet Premier Khrushchev
declared, through unilateral public statements, a
moratorium on nuclear testing and began negotiations on acomprehensivetest ban. The United States
adopted the moratorium after conducting 13 tests in
seven daysat the end of October 1958. Negotiations
broke downfirst over the right to perform onsite
inspections, and then over the number of such
inspections. In December 1959, President Eisenhower announced that the United States would no
longer consider itself bound by the ‘‘voluntary
moratorium’’ but would give advance notice if it
decided to resumetesting. Meanwhile (during the
moratorium), the French began testing their newly
acquired nuclear capability. The Soviet Union,
which had announced that it would observe the
moratorium as long as the western powers would not
test, resumedtesting in September 1961 with a series
of the largest tests ever conducted. The United States
resumedtesting two weekslater (figure 2-1).!°
Public opposition to nuclear testing continued to
mount. Recognizing that the U.S. could continueits
development program solely through underground
testing and that theratification of a comprehensive
test ban could not be achieved, President Kennedy
proposed a limited ban on tests in the atmosphere,
the oceans, and space. The Soviets, who through
their own experience were convinced that their test
program could continue underground, accepted the
proposal. With both sides agreeing that such a treaty
could be readily verified, the Limited Test Ban
Treaty (LTBT) was signed in 1963, banning ail
abovegroundor underwatertesting.
In addition to military applications, the engineering potential of nuclear weapons was recognized by
the mid-1950’s. The Plowshare Program was formed
in 1957 to explore the possibility of using nuclear
explosions for peaceful purposes.'!! Among the
6Bravo was the largest test ever detonated by the United States.
7See ‘The Voyage of the Lucky Dragon,"’ Ralph E. Lapp, 1957, Harper & Brothers Publishers, New York.
8** Arms Control and Disarmament Agreements,"’ United States Arms Control and Disarmament Agency, Washington, DC, 1982 Edition, p. 34.
9Since the large thermonuclear tests,all people have strontium-90 (a sister element of calcium) in their bones, and cesium-137(a sister element of
potassium) in their muscle. Also, the amount of iodine-131 in milk in the United States correlates with the frequency of atmospheric testing.
10See ‘Arms Control and Disarmament Agreements,’’ United States Arms Control and Disarmament Agency, 1982 edition.
‘!The name is from ‘‘.... they shail beat their swords into plowshares,’’ Isaiah 2:4.