![Cerenkov Effect](https://upload.wikimedia.org/wikipedia/commons/6/6b/Cerenkov_Effect.jpg)
The Reed Research Reactor (RRR) () is a research
nuclear reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nu ...
located on-campus at
Reed College
Reed College is a private liberal arts college in Portland, Oregon. Founded in 1908, Reed is a residential college with a campus in the Eastmoreland neighborhood, with Tudor-Gothic style architecture, and a forested canyon nature preserve at ...
in
Portland, Oregon
Portland (, ) is a port city in the Pacific Northwest and the largest city in the U.S. state of Oregon. Situated at the confluence of the Willamette and Columbia rivers, Portland is the county seat of Multnomah County, the most populous co ...
. It is a pool-type
TRIGA
TRIGA (Training, Research, Isotopes, General Atomics) is a class of nuclear research reactor designed and manufactured by General Atomics. The design team for TRIGA, which included Edward Teller, was led by the physicist Freeman Dyson.
Design
...
Mark I reactor, built by
General Atomics
General Atomics is an American energy and defense corporation headquartered in San Diego, California, specializing in research and technology development. This includes physics research in support of nuclear fission and nuclear fusion energy. The ...
in 1968 and operated since then under licence from the
Nuclear Regulatory Commission
The Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operat ...
. Maximum thermal output is 250 kW. The reactor has over 1,000 visitors each year and serves the Reed College departments of Physics and Chemistry, as well as other departments.
Operation
RRR is the only research reactor in the world that is owned and operated by an
undergraduate
Undergraduate education is education conducted after secondary education and before postgraduate education. It typically includes all postsecondary programs up to the level of a bachelor's degree. For example, in the United States, an entry-lev ...
educational institution. It is operated and maintained by undergraduate college students under the supervision of a director and operations manager who are members of the college staff. The facility provides scientific irradiation services to a broad community outside the college, but its primary mission is for student initiated research, training, and hands-on education.
The Reed Research Reactor is intended to produce
thermal neutrons
The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts. The term ''temperature'' is used, since hot, thermal and cold neutrons are moderated in a medium with ...
. It is used primarily for
neutron activation
Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus decays immediately by emittin ...
to produce radioisotopes or analyze composition of material samples.
Undergraduate leadership
The RRR distinguishes itself from other university
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 maritim ...
s by the fact that it is the only reactor run completely by undergraduate students and serves undergraduate degree programs almost exclusively. In fact,
Reed College
Reed College is a private liberal arts college in Portland, Oregon. Founded in 1908, Reed is a residential college with a campus in the Eastmoreland neighborhood, with Tudor-Gothic style architecture, and a forested canyon nature preserve at ...
does not have any
nuclear engineering
Nuclear engineering is the branch of engineering concerned with the application of breaking down atomic nuclei ( fission) or of combining atomic nuclei (fusion), or with the application of other sub-atomic processes based on the principles of n ...
or even any
engineering
Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ...
program.
The facility is used in research projects, often conducted by the campus itself. As of November 2018, there are approximately 40 students licensed to operate the reactor. In order to obtain such a license, students must attend a year of seminars on nuclear safety followed by an exam administered by the
Nuclear Regulatory Commission
The Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operat ...
.
When the facilities were visited by
ABC
ABC are the first three letters of the Latin script known as the alphabet.
ABC or abc may also refer to:
Arts, entertainment, and media Broadcasting
* American Broadcasting Company, a commercial U.S. TV broadcaster
** Disney–ABC Television ...
's "Radioactive Roadtrip" ''
Primetime
Prime time or the peak time is the block of broadcast programming taking place during the middle of the evening for a television show. It is mostly targeted towards adults (and sometimes families). It is used by the major television networks to ...
'' special, the fact that the school had no engineering program was purported as evidence that university reactors are sometimes kept as more of a status symbol than as a valid research tool. This is a quote from the ABC website:
University Reaction: The reactor is a "zero-risk facility," and there is no plausible way it is a threat, said Edward Hershey, director of public affairs at Reed College. Although the school has no nuclear engineering department – or any engineering department for that matter – chemistry and physics students use it as a resource. Hershey said the reactor is a "bragging point" for Reed. "It's just a neat facility," he said.
The "zero-risk facility" comment reflects the reactor design which is a pin-type
Low Enriched Uranium
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238 ...
natural circulation driven LWR, with a very strong
negative temperature coefficient
A temperature coefficient describes the relative change of a physical property that is associated with a given change in temperature. For a property ''R'' that changes when the temperature changes by ''dT'', the temperature coefficient α is def ...
. As such, it is impossible to overheat the reactor, even in the case of a sudden
reactivity insertion.
Irradiation facilities
Irradiation facilities include equipment that is used to place, move, and organize samples that are to be irradiated.
Pneumatic transfer system
The pneumatic transfer system (known colloquially as the "rabbit system") consists of an irradiation chamber in the outer ring of the core with its associated pump and piping. This allows samples to be transferred in and out of the reactor core very rapidly, while the reactor is at power. Routine use of the pneumatic transfer system involves placing samples into vials, which in turn are placed in special capsules known as "rabbits." The capsule is loaded into the system in the radiochemistry laboratory next to the reactor and is then transferred pneumatically into the core-irradiation position for a predetermined time. At the end of this period, the sample is transferred back to the receiving terminal, where it is removed for measurement. The transfer time from the core to the terminal is less than seven seconds, making this method of irradiating samples particularly useful for experiments involving radioisotopes with short half-lives. The flux in the core terminal is approximately 5x10
12 n/cm
2/s when the reactor is at full power.
Rotating specimen rack
The rotating specimen rack (
lazy susan
A Lazy Susan is a turntable (rotating tray) placed on a table or countertop to aid in distributing food. Lazy Susans may be made from a variety of materials but are usually glass, wood, or plastic. They are circular and placed in the centre o ...
) is located in a well on top of the graphite reflector which surrounds the core. The rack consists of a circular array of 40 tubular receptacles. Each receptacle can accommodate two TRIGA-type irradiation tubes, so that up to 80 separate samples may be irradiated at any one time. Vials holding up to ( internal diameter, long) are routinely used in this system. Depending upon its geometry, a sample up to about could be irradiated by joining two vials. Samples are loaded in the specimen rack prior to the start-up of the reactor. The rack automatically rotates during irradiation to ensure each sample receives the same neutron flux. Typically, the rotating rack is used by researchers when longer irradiation times (generally greater than five minutes) are required. The average thermal neutron flux in the rotating rack position is approximately 2×10
12 n/cm
2/s with a cadmium ratio of 6.0 at full power. The specimen rack can also be used for gamma irradiations when the reactor is shut down. The shutdown gamma flux in the specimen rack is approximately 3 R/min.
Central thimble
The central thimble, which is a water-filled irradiation chamber about in diameter, provides the highest available neutron flux, about 1.4x10
13 n/cm
2/s. However, it holds only one specially positioned irradiation container, containing a cavity in length and in diameter.
Another in-core location is available by replacing one of the fuel elements with an irradiation chamber. The chamber fits into a fuel-element position within the core itself.
Foil-insertion holes, in diameter, are drilled at various positions through the grid plates. These holes allow inserting special holders containing flux wires into the core, to obtain neutron flux maps of the core.
In-pool facilities
Near core, in-pool irradiation facilities can be arranged for larger samples. Neutron fluxes will be lower than in the lazy susan and will depend on the sample location.
References
; General
*
;Specific
External links
*
{{authority control
1968 establishments in Oregon
Nuclear research reactors
Reed College campus