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Nevada Test Site
Updated
9/30/06
Shundahai
Network's Subcritical Nuclear Weapons Tests Information Page
April 4 , 2006 - Western
Shoshone Defense Project and Shundahai Network Release joint Statement
on "Divine Strake" News articles and information on
an event to oppose the test are posted here.
February 23, 2006 - Krakatau
Subcritical Nuclear Weapons Experiment Conducted at the Nevada Test
Site More information about subcritical nuclear weapons tests
can be found here.
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Click on the map to see
information about that area
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The Nevada Test Site (topo map)
is a Rhode Island-sized testing ground northwest of Las Vegas where
the U.S. conducted the majority of its nuclear weapons tests during
the Cold War. Initially the NTS, originally called the Nevada Proving
Grounds, consisted of 680 square miles, about half its present size.
Additional land was added in 1958, 1961, 1964, and 1967.
From the end of World War II until 1951, five
US nuclear weapons tests were conducted at distant islands in the
Pacific Ocean. When the decision to accelerate the development of
nuclear weapons was made in the late 1940s, it became apparent that
weapons development lead times would be reduced and considerably
less expense incurred if nuclear weapons, especially the lower yield
weapons, could be tested within the continental boundaries.
An area within what is now the Nellis Air Force
Range was selected to meet criteria for atmospheric tests. The Southern
Nevada site was selected from a list of five possibilities which
included Alamogordo/White Sands, New Mexico; Dugway Proving Ground,
Utah; Pamilco Sound/Camp Lejuene, North Carolina; and a 50-mile-wide
strip between Fallon and Eureka.
Nevada. Public Land
Order 805 dated 19 February 1952, identified 680 square miles (1,800
square kilometers) for nuclear testing purposes from an area used
by the Air Force as a bombing and gunnery range; this area now comprises
approximately the eastern half of the present Nevada Test Site.
The decision to created
the Nevada Test Site was made by President Harry Truman on Jan.
11, 1951, and the first atomic test, Operation
Ranger, was conducted on Jan. 27, 1951.
When the Ranger Series ended in 1951, AEC initiated
plans to expand the Test Site facilities. Construction began on
utility and operational structures, including communications, a
control point, and additional accommodations. As a safety measure,
AEC decided to move the testing area from Frenchman Flat to Yucca
Flat, where 12 areas were developed for air drops, tower, surface,
tunnel and balloon tests. Additional land was added to the site
in 1958, 1961, 1964, 1967and 1998, thereby enlarging the site to
its present size of about 1,350 square miles (3,500 square kilometers).
 Nuclear
testing at the NTS was conducted in two distinct eras: the atmospheric
testing era (January 1951 through October 1958) and the underground
testing era (1961 to 1992). On 31 October 1958, the United States
and the Soviet Union entered into voluntary test moratoria which
lasted until the USSR. resumed testing on 01 September 1961. The
United States responded with renewed testing on 15 September 1961.
A few surface, near surface, and catering tests were conducted
from 1961 to 1968, but all other nuclear weapons tests have been
carried out underground since 1961. The United States and the
Soviet Union signed the Limited Test Ban Treaty on 05 August 1963,
which banned testing nuclear weapons in the atmosphere, in outer
space and underwater. Six of the eight cratering tests conducted
between 1962 and 1968 were part of a peaceful applications program.
The United States conducted 119 nuclear tests
at the NTS from the start of testing in January 1951 through October
1958. Most of those nuclear tests were carried out in the atmosphere.
Some tests were positioned for firing by airdrop, but metal towers
were used for many Nevada tests at heights ranging from 100 to
700 feet (30-200 meters) above the ground surface. In 1957 and
1958, helium-filled balloons, tethered to precise heights and
locations 340 to 1,500 feet (105 to 500 meters) above ground,
provided a simpler, quicker, and less expensive method for the
testing of many experimental devices. The tests of the atmospheric
era took place in Yucca and Frenchman Flats. The 119 nuclear tests
that were conducted at the NTS during the atmospheric testing
era (1951-1958) consist of 97 nuclear tests conducted in the atmosphere,
of two cratering tests, detonated at depths less than 100 feet
(30 meters), and of 20 underground tests.
In 1962, before the onset of the Limited Test
Ban Treaty, the United States conducted, in addition to its underground
tests, two small surface tests, one tower test and two cratering
tests as part of the nuclear weapons testing program. Six nuclear
cratering tests were conducted from 1962 through 1968 as part
of the peaceful applications (Plowshare) program. The overwhelming
majority of the 809 tests that took place at the NTS from 1961
through September 1992 were conducted underground either in shafts
or in tunnels that were designed for containment of the radioactive
debris. Most underground tests were conducted under Yucca Flat
but a few underground and cratering tests took place under Buckboard,
Pahute, and Rainier Mesas in the northern part of the Nevada Test
Site.
When drilling of vertical shafts for underground
tests at the NTS began in 1959, the biggest problem was the time
it took to drill into the desert floor. A 36-inch diameter hole,
1,000 feet deep, could take up to 60 days. The initial method
was to drill in three successive passes, each one larger. Eventually
the tri-stage gave way to the flat bottom bit, with 12 to 24 cutters
chewing up the rock as the entire unit rotated -- a process that
could drill a 1,000-foot hole in 20 days. A normal hole is from
1 to 3 meters (m) (48 to 120 inches [in.]) diameter and from 213
to 762 meters (m) (600 to 2,500 feet [ft]) deep.
Tests in vertical drill holes are of two types:
smaller-yield devices in relatively shallow holes in the Yucca
Flat area (Areas 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10) and higher-yield
devices in deeper holes on Pahute Mesa (Areas 18, 19, and 20).
Tests at the Yucca Flat and Pahute Mesa event sites have the same
general requirements, but differ in the magnitude of the operations.
Deeper-hole operations disturb a larger area, require more on-site
equipment, and have a higher requirement for electrical power
and utilities. The distance from the core of the infrastructure
is also a factor; Pahute Mesa operations are 48 to 81 kilometers
(km) (30 to 50 miles [mi]) farther away than Yucca Flat.
Tests have been conducted in 16 different tunnels
in Rainier Mesa on the Nevada Test Site. The first test was conducted
on 10 August 1957, when a zero-yield safety experiment named "Saturn"
was detonated in C-Tunnel. By the early 1990s there was only one
active tunnel in use by the Defense Nuclear Agency (DNA). The
DNA evaluated the effects of nuclear weapons explosions, thermal
radiation, blast, shock, x-rays and gamma rays, on military hardware,
such as communication equipment, rocket nosecones, and satellites.
The typical Horizontal Line of Site (HLOS) test was primarily
for radiation effects research. Researchers attempted to minimize
blast and shock effects from the experiments. A large tunnel complex
mined under the mesa contained the HLOS pipe. The HLOS pipe is
1,500 to 1,800 feet long and tapers from up to 30 feet in diameter
at the test chamber to several inches at the working point. Experiments
were placed in the HLOS pipe test chambers. At zero time the nuclear
device is fired, and radiation instantaneously flows down the
pipe, creating the necessary radiation environment. To prevent
bomb debris and blast from reaching and damaging the experiments,
three mechanisms were used to close the pipe. The first is the
Fast Acting Closure which is slammed shut by high explosives in
about one millisecond; the other two closures follow within 30
and 300 milliseconds
The most detailed information available about
venting and other releases comes form the US, where the US congressional
Office of Technological Assessment (OTA) did a study in 1989 which
found that between 1970 and 1988 there were releases of radioactivity
from 126 underground tests. 4 were ‘containment failures’ i.e.
unintentional releases due to the failure of the containment system.
4 were late time seeps which are small releases that occur days
or weeks after a test when gases diffuse through pore spaces of
the overlying rock and are drawn to the surface by decreases in
the atmospheric pressure. 10 were due to ‘controlled tunnel purging’
which are intentional releases to allow either recovery of experimental
data and equipment or the reuse of part of the tunnel system.
108 were operational releases i.e. deliberate releases that occur
during operations such as collection of gas samples. The unintentional
releases i.e. venting have released the most radioactivity. For
example the most significant venting incidents reported by the
OTA include the Baneberry Test in 1970 which released 6.7 million
Curies of radioactivity after detonation at a depth of about 270m.
It produced a cloud of radioactive dust about 3km above the Earth’s
surface. The Plattee test in 1962 released 1.9 million Curies,
the DEs Moines test in 1962 released 1.1 million Curies and 26
other tests together released around 3.8 million Curies.
As many as 38 underground events detonated
through September 1992 released volatile radioactive materials
(particulate or gaseous), which resulted in detection off-site.
The remainder of the 809 tests that took place at the NTS between
1961 and 1992 were either completely contained underground or
resulted in releases of radioactive materials that were only detected
onsite. A total of 299 events resulted in releases of radioactive
materials that were detected on-site only.
The total number of nuclear weapons tests that
were conducted at the Nevada Test Site up to September 1992 is
928 --— 100 which were atmospheric, and the other 828 underground.
On 02 October 1992, the United States entered into another unilateral
moratorium on nuclear weapons testing announced by President Bush.
President Clinton extended this moratorium in July 1993, and again
in March 1994.
President Clinton directed the Department to maintain a basic
capability to resume nuclear testing activities at the NTS should
the United States deem it necessary.
One way DOE proposes to retain this capability
is to conduct a series of subcritical experiments with nuclear
materials at the NTS. Subcritical experiments use high explosives
to create some of the physical conditions, such as pressure and
temperature, that nuclear materials undergo in a nuclear weapon
before reaching the critical stage.They are called "subcritical"
because they are not expected to reach "critical mass."But
at LLNL in Livermore, Calif.on Mar. 26, 1963 A nuclear excursion
and subsequent fire took place during a subcritical experiment
in a shielded vault designed for critical assembly experiments.
The excursion was estimated at 4 X 1017 fissions and was followed
by oxidation of the enriched uranium metal in the assembly. (from
Operational Accidents and Radiation Exposure Experience Within
the United States Atomic Energy Commission, 1943-1970, U.S. Government
Printing Office: Washington, D.C., 1971.)
 In
the 1950s, atomic tests were conducted above
ground and resulted in devastating health effects to the "Downwinders"
northeast of the site in Nevada and Utah. Since then, tests were
conducted only
underground, resulting in a pockmarked "lunar" landscape.
From its founding in 1951 until the final Divider test on Sept.
23,1992, 99 above ground tests and over 800 below ground nuclear
tests were detonated in this desert. There have been 1054 nuclear
tests conducted by the United States. Twenty-four of these tests
were done jointly with the United Kingdom, and of the 1054 tests,
928 tests were conducted at the NTS. One hundred twenty-six tests
were conducted at other locations in and outside of Nevada.
The NTS is operated by the Department of Energy,
and is bounded on three side by the
Nellis Air Force Range. Today, the Test Site is under consideration
for various storage and processing projects for dangerous materials,
non-nuclear and subcritical nuclear tests (see yellow sidebar)
are still conducted there.
The NTS is broken up into
numbered areas of varying sizes, from 1 to 30, with the omission
of Areas 13, 21, 24 and 28. (Area 13 is an off-site location in
the Nellis Range north of Groom Lake.) Today, most of the work
on the NTS continues to be related to nuclear weapons development.
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