Idaho National Laboratory Cultural Resource Management Plan

Arco NPG land and infrastructure were
acquired from the Navy by the AEC in 1949 and
formed the nucleus of the future INL.
Nuclear Science and Engineering
The federal government initially established
INL as the NRTS in 1949. Its purpose was to
provide an isolated location where prototype
nuclear reactors could be designed, built, and
tested. The Naval Proving Ground buildings
acquired by the AEC became known as the Central
Facilities Area. As its name suggests, CFA served
as a centralized support services facility for the
reactor testing operations, containing such jointly
used services as a fire department, medical
dispensary, cafeteria, crafts shops, and motor
vehicle repair and maintenance facilities (Braun
1996). Since establishment of the NRTS, 52 “firstof-a-kind”
reactors have been constructed at INL.
The following contextual overview and the
supporting text in Appendix F focus on major
nuclear-era research and testing programs by
facility area and are not intended as a
comprehensive history. A more complete and
definitive context, including an inventory of INL
buildings administered by DOE-ID for post-1942
INL activities, can be found in the INL CRMP.
Additional detail is provided by a popular history
of INL (Stacy 2000) and several Historic
American Engineering Record reports.
Experimental Breeder Reactor I. The first
reactor built at INL, Experimental Breeder Reactor
I (EBR-I), reached initial criticality on August 24,
1951, and achieved many historical firsts during
its operational lifetime. On December 20, 1951,
shortly after initial startup, the facility became the
first reactor in the world to produce usable
quantities of electricity. Subsequently, in 1953,
EBR-I proved the concept that reactors designed
to operate in the high-energy neutron range are
capable of creating more fuel than is consumed
(i.e., breeding). This was an important concept in
the 1950s because uranium, the main ingredient in
reactor fuel, was thought to be in short supply. In
1955, EBR-I inadvertently experienced a core
meltdown and proved that the consequence of
such an event was not necessarily catastrophic
(Braun 2006B). In July of 1963, EBR-I became
the first reactor in the world to generate usable
electricity with plutonium as the major fuel
component and, later, also demonstrated the
feasibility of using liquid metal as a reactor
coolant. The reactor was decommissioned in 1964,
named an NHL on December 21, 1965, 14 years
after its first historic event occurred, and opened
for public visitation in 1975. In 1979 it was
recognized as an American Society of Mechanical
Engineering Landmark and in 1985 was awarded
the same honor by the American Nuclear Society
(Braun 2006A; Braun 1994; INEL 1969) (see
Figure 19).
Figure 19. EBR-1 National Historic Landmark.
Advanced Test Reactor Complex. The first
reactor built expressly for testing reactor core and
fuel materials, the Materials Test Reactor (MTR)
achieved startup on March 31, 1952, at the INL
area now known as Advanced Test Reactor
Complex (ATRC) (formerly the Test Reactor Area
[TRA] 2 ). Experiments conducted at MTR
influenced the choice of fuel elements and core
structural materials for every reactor constructed
in the United States since MTR startup. After
more than 125,000 operating hours, MTR was
finally shut down on April 25, 1970, and was
formally decommissioned in 1974. Until 2007, the
MTR building was maintained and used for office
and laboratory space and storage.
To enhance the nation’s reactor testing
capability, the Engineering Test Reactor (ETR)
was completed in 1957, just a few hundred feet
2. Unless otherwise specified for historical purposes, the
INL area originally known as TRA is primarily referred
to in this section by its current designation of ATRC.
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