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The first underground physics experiment near Carlsbad was Project Gnome,
December 10, 1961
|Totally unrelated (and many years prior) to WIPP, the Project Gnome detonation was
the first U.S. underground nuclear test with the objective of using nuclear explosives for
peaceful applications. Project Gnome was intended to provide a detailed
understanding of the underground environment created when a nuclear
explosion was detonated in thick salt deposits.
The nuclear device was emplaced 1,184 feet underground in bedded salt at the
end of a 1,116 ft hooked tunnel designed to be self-sealing. A shaft 1,216 ft
deep ended in a station room connected to the tunnel.
|The Gnome device was detonated at noon local time with a yield of 3.1
it had been planned as a contained explosion, the detonation resulted in venting to the atmosphere.
Smoke, steam and radioactive material began venting from the top of the access shaft (1100 ft
southwest of the underground detonation) 2 to 3 minutes after
the detonation. Significant venting continued for about 30 minutes and
then began to decrease gradually. The highest measured onsite gamma intensity
was 1 R/hr. This intensity was recorded 1,300 meters northwest of the shaft
opening at 7:38pm on the day of the shot. The highest offsite reading was 1.4
R/hr, which was briefly encountered along Highway 128 one hour after detonation
(about 5 miles to the northwest of the site). The surface
radioactivity resulting from the escape of steam decayed rapidly. On the
following day, a small flow of steam was still detectable and underground
recovery operations were delayed,
in part because of the high radiation levels at the shaft opening (for example,
5 R/hr at 9:08am the next morning). Re-entry excavation began six days
after the test, and the cavity was entered about 6 months later on May 17, 1962.
||There were other goals
attempted with Project Gnome. It was the first test as part of the "Plowshare" program.
Because of the widely increased use of radioisotopes in scientific experiments,
medical diagnosis and therapy, agriculture, and industrial production, Plowshare
scientists sought to find new means for manufacturing and recovering isotopes.
Previous underground nuclear tests had demonstrated that large quantities of
radionuclides (for radio-pharmaceutical and therapeutic applications) become entrapped in the molten rock formed by an underground
nuclear explosion. Since recovery is difficult when common silicate rock solidifies, a
different matrix for the radionuclides was sought. It was hoped that salt,
being water soluble, could be processed to easily recover the radionuclides for
||Re-entry was through an
underground tunnel excavated parallel to the original one. The roughly
hemispheric cavity measuring 160-170 feet in diameter (larger than the
base of the dome of the U. S. Capitol building) and 60-80 feet high
(equivalent to a 7-8 story building) is shown in the photo at left.
Temperatures up to 130 degrees were recorded. Although some "hot
spots" of radiation were found, the general level was from 0.05-0.06
R/hr. Today's radiation level in the cavity is 0.005-0.015 R/hr (about
the same as natural background levels found at the surface). The
earlier intense radiation had colored the salt of the cavity wall various shades
of blue, green, and violet. The test was conducted for the U.S. Atomic Energy Commission
by the Lawrence Radiation Laboratory, Livermore, California.
|The Plowshare Program was created in the late fifties to
explore the possible use of nuclear explosive devices for peaceful uses.
From 1961-73, researchers carried out 27 separate experiments under
Project Plowshare, setting off 35 nuclear detonations. Most of the tests
were conducted at the Nevada Test Site, but some were also conducted in
New Mexico and Colorado. Others were proposed,
but not conducted in other states and nations. The experiments focused
mostly on creating craters and canals, producing radioactive elements,
reducing radioactive fallout and stimulating natural gas production from underground
they will have to beat their swords into plowshares and their spears into
pruning shears. Nation will not lift up sword against nation, neither will
they learn war anymore.'' - Isaiah 2:4
clips available from DOE's Office of Science & Technology Information
From 1965-88, Russia explored a program similar to Plowshare that
detonated 128 nuclear explosives for nonmilitary experiments. A
common goal to develop peaceful uses for nuclear explosives led to
ice-breaking meetings between nuclear scientists in Russia and the United
States - meetings that allowed Cold War adversaries to share their
knowledge of civilian applications for nuclear explosives.
the Nevada Test Site (NTS), nuclear testing activities were conducted at eight
locations in five different states as part of the Nuclear Weapons Testing, the
Vela Uniform, and the Plowshare Programs. As part of the Plowshare
Program, nuclear tests were conducted at two sites near Rifle, Colorado (Rulison
and Rio Blanco), southwest of Dulce, New Mexico (Project Gasbuggy), and near
Carlsbad, New Mexico (Project Gnome-Coach). Projects Rulison, Rio Blanco, and
Gasbuggy were designed to stimulate the production of natural gas in tight
As part of the Vela
Uniform Program, nuclear tests were conducted near Fallon, Nevada (Project
Shoal), on Amchitka Island, Alaska (Project Long Shot), and near Hattiesburg,
Mississippi, (Projects Salmon and Sterling). Projects Shoal and Long Shot were
designed to determine the behavior and characteristics of seismic signals
generated by nuclear detonations and to differentiate them from seismic signals
generated by naturally occurring earthquakes. Projects Salmon and Sterling were
designed to evaluate seismic signals from both coupled and decoupled detonations
in a salt medium (the Tatum Salt Dome).
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