Idaho National Laboratory Cultural Resource Management Plan

History: 1942 to Present
In 1942, the U.S. Navy established a presence
on what is now INL to test naval ordnance. After
World War II, nonnuclear military munitions
testing continued until the AEC acquired the
former ordnance test area for development of a
remote installation devoted to testing and
developing nuclear reactor technologies.
Prototypes of the nation’s three commercial power
reactor concepts—the pressurized water reactor,
the boiling water reactor, and liquid-metal-cooled
breeder reactor—were first developed and tested at
this National Reactor Testing Station ([NRTS]—
now INL). Since its formation as the NRTS in
1949, basic research critical to design, safe
operation, and licensing of nuclear power and
propulsion reactors has taken place at INL.
Military Ordnance Testing
During World War II, the U.S. Naval
Ordnance Plant was established in Pocatello,
Idaho, as a place to manufacture, assemble, and
reline Navy weapons. Nearly all of the naval ship
guns used by the Pacific Fleet were eventually sent
to the plant for relining. Before the guns could be
shipped back for active duty, they had to be test
fired to ensure that their aim was true. The Arco
Naval Proving Ground (NPG) was established
some 60 miles northwest of Pocatello as a remote
place to test the guns for combat readiness. While
operating during World War II, it was one of only
six such facilities in the United States and the only
one capable of test firing the Pacific Fleet’s
16-inch battleship guns.
The Arco NPG included some 270 square
miles of land and infrastructure, including
operational support facilities and housing for
military and civilian personnel. This infrastructure
is primarily located at what is today the INL
Central Facilities Area (CFA), but also included
rail lines and roads for gun transport and
downrange activities and various targets, spotting
towers, and detonation areas. The Army Air
Corps, flying out of Pocatello, also established two
practice bombing ranges near the Arco NPG at this
time, one located southwest of CFA and the other
southeast (Braun 1996; Scientech Inc. 1993; Stacy
2000).
After the end of World War II, ordnance
testing at the Arco NPG continued in the form of
explosives storage and transportation tests.
Structures were built and then loaded with
explosives that were intentionally discharged to
assess the effects to the structures and surrounding
area of such explosions and to determine safe
storage of military ordnance. One such test
occurred on August 29, 1945, when 250,000
pounds of TNT were detonated. The explosion
created a mile high smoke and dust cloud and a
crater fifteen feet deep. Another test on October
31, 1946, detonated 500,000 pounds of excess
high explosives to determine the safe distance for
explosive ordnance storage in the open. At the
time, this was believed to be the world's largest
conventional ordnance explosion (Wylie,
Appendix B; also EG&G Idaho 1986). Craters and
debris from this and other ordnance tests still
remain on the INL landscape.
Between 1968 and 1970, during the Vietnam
War, massive 16-inch naval guns were again heard
on the Idaho desert (see Figure 18). A naval firing
site, located southwest of CFA, was established
and used for test firing the battleship New Jersey’s
armament. Since AEC research facilities were then
scattered throughout the original downrange area
of the Arco NPG, the guns tested at that time were
aimed in the opposite direction. From the firing
site located a few miles south of CFA, the guns
were aimed southward across uninhabited territory
toward the Big Southern Butte. Craters can still be
found on the northern flank of the butte (Braun
1996; Coloff 1965).
Figure 18. Sixteen-inch naval gun being tested at
area now known as INL during the Vietnam war.
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