Experimental Breeder Reactor I (EBR-I) is a decommissioned
research reactor
Research reactors are nuclear fission-based nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or marit ...
and
U.S. National Historic Landmark
A National Historic Landmark (NHL) is a National Register of Historic Places property types, building, district, object, site, or structure that is officially recognized by the Federal government of the United States, United States government fo ...
located in the desert about southeast of
Arco, Idaho. It was the world's first
breeder reactor. At 1:50 p.m. on December 20, 1951, it became one of the world's first electricity-generating
nuclear power plants when it produced sufficient electricity to illuminate four 200-watt
light bulbs.
EBR-I subsequently generated sufficient electricity to power its building, and continued to be used for experimental purposes until it was decommissioned in 1964. The museum is open for visitors from late May until early September.
History
As part of the
National Reactor Testing Station (since 2005
Idaho National Laboratory), EBR-I's construction started in late 1949. The reactor was designed and constructed by a team led by
Walter Zinn
Walter Henry Zinn (December 10, 1906 – February 14, 2000) was an American nuclear physicist who was the first director of the Argonne National Laboratory from 1946 to 1956. He worked at the Manhattan Project's Metallurgical Laboratory during W ...
at the
Argonne National Laboratory Idaho site, known as Argonne-West. In its early stages, the reactor plant was referred to as
Chicago Pile 4 (CP-4) and Zinn's Infernal Pile. Installation of the reactor at EBR-I took place in early 1951 (the first reactor in Idaho) and it began power operation on August 24, 1951. On December 20 of that year, atomic energy was successfully harvested at EBR-1 for the first time. The following day, the reactor produced enough power to light the whole building. The power plant produced 200
kW of electricity out of 1.4
MW of
heat
In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...
generated by the reactor.

The design purpose of EBR-I was not to produce electricity but instead to validate
nuclear physics theory that suggested that a
breeder reactor should be possible. In 1953, experiments revealed the reactor was producing additional fuel during
fission
Fission, a splitting of something into two or more parts, may refer to:
* Fission (biology), the division of a single entity into two or more parts and the regeneration of those parts into separate entities resembling the original
* Nuclear fissio ...
, thus confirming the hypothesis. On November 29, 1955, the reactor at EBR-I suffered a partial
meltdown
Meltdown may refer to:
Science and technology
* Nuclear meltdown, a severe nuclear reactor accident
* Meltdown (security vulnerability), affecting computer processors
* Mutational meltdown, in population genetics
Arts and entertainment Music
* ...
during a coolant flow test. The flow test was trying to determine the cause of unexpected reactor responses to changes in coolant flow. It was subsequently repaired for further experiments, which determined that thermal expansion of the fuel rods and the thick plates supporting the fuel rods was the cause of the unexpected reactor response.
Although EBR-I produced the first electricity available in-house, a nearby experimental boiling water reactor plant called
BORAX-III (also designed, built, and operated by Argonne National Laboratory) was connected to external loads, powering the nearby city of
Arco, Idaho in 1955, the first time a city had been powered solely by nuclear power.
Besides generating the world's first electricity from atomic energy, EBR-I was also the world's first breeder reactor and the first to use
plutonium
Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhib ...
fuel to generate electricity (see also the
Clementine nuclear reactor). Correction: The world's first electricity from atomic energy was generated 3 years earlier in September 1948 at the X-10 Graphite Reactor at the Oak Ridge National Lab in Tennessee. EBR-I's initial purpose was to prove
Enrico Fermi's fuel breeding principle, a principle that showed a nuclear reactor producing more fuel atoms than consumed. Along with generating electricity, EBR-1 would also prove this principle.
Design
EBR-I used uranium metal fuel and
NaK
In data networking, telecommunications, and computer buses, an acknowledgment (ACK) is a signal that is passed between communicating processes, computers, or devices to signify acknowledgment, or receipt of message, as part of a communications ...
primary coolant. It was in this identical to the initial configuration of the later
Dounreay Fast Reactor which first went
critical
Critical or Critically may refer to:
*Critical, or critical but stable, medical states
**Critical, or intensive care medicine
*Critical juncture, a discontinuous change studied in the social sciences.
*Critical Software, a company specializing in ...
in 1959.
Decommission and legacy
EBR-I was deactivated by Argonne in 1964 and replaced with a new reactor,
Experimental Breeder Reactor II
Experimental Breeder Reactor-II (EBR-II) is a sodium-cooled fast reactor designed, built and operated by Argonne National Laboratory at the National Reactor Testing Station in Idaho. .
It was declared a
National Historic Landmark
A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed ...
in 1965
[ and ] with its dedication ceremony held on August 25, 1966, led by President
Lyndon Johnson and
Glenn T. Seaborg
Glenn Theodore Seaborg (; April 19, 1912February 25, 1999) was an American chemist whose involvement in the synthesis, discovery and investigation of ten transuranium elements earned him a share of the 1951 Nobel Prize in Chemistry. His work i ...
. It was also declared an
IEEE Milestone in 2004.
Gallery
Ebri_plaques.jpg, Plaques at the EBR-I site
Ebr1core.png, Assembly of the EBR-1 core in 1951
First four nuclear lit bulbs.jpeg, The first production of usable nuclear electricity occurred on December 20, 1951, when four light bulbs were lit with electricity generated from the EBR-1 reactor.
Ebr-1.zdv.jpg, The reactor is in the building at center; the two structures lower left are reactors from the Aircraft Nuclear Propulsion Project.
EBR-1 2001.jpg, View of EBR-1, from the parking lot
See also
*
Argonne National Laboratory
*
Obninsk Nuclear Power Plant
Obninsk Nuclear Power Plant (russian: Обнинская АЭС, Obninskaja AES; ) was built in the "Science City" of Obninsk,[Calder Hall
Sellafield is a large multi-function nuclear site close to Seascale on the coast of Cumbria, England. As of August 2022, primary activities are nuclear waste processing and storage and nuclear decommissioning. Former activities included nuc ...]
, England, the first nuclear power station to deliver power in commercial quantities.
*
Aircraft Nuclear Propulsion Project
*
Idaho National Laboratory
*
List of National Historic Landmarks in Idaho
__NOTOC__
This is a complete List of National Historic Landmarks in Idaho. The United States National Historic Landmark program is operated under the auspices of the National Park Service, and recognizes structures, districts, objects, and similar ...
*
National Register of Historic Places listings in Butte County, Idaho
References
;Citations
;Bibliography
Argonne National Laboratory EBR-1– The EBR-1 reactor was designed, built, and operated by
Argonne National Laboratory.
Page about EBR-1 at INL web siteINL EBR-1ANS EBR-I HistoryAtomic Heritage Foundation
External links
*
*
*
ERB-1 Core Disassembly
{{authority control
Buildings and structures in Butte County, Idaho
Energy infrastructure completed in 1951
Decommissioned nuclear power stations in the United States
Nuclear power plants in Idaho
Fast-neutron reactors
Historic Mechanical Engineering Landmarks
National Historic Landmarks in Idaho
Nuclear research reactors
History museums in Idaho
Science museums in Idaho
Museums in Butte County, Idaho
Industrial buildings and structures on the National Register of Historic Places in Idaho
National Register of Historic Places in Butte County, Idaho
Energy infrastructure on the National Register of Historic Places
Nuclear accidents and incidents in the United States