Research and Test Reactors

Background

Research and test reactors – also called “non-power” reactors – are nuclear reactors 

primarily used for research, training and development. These reactors contribute to almost every 

field of science including physics, chemistry, biology, medicine, geology, archeology, and 

environmental sciences. 

The U.S. Nuclear Regulatory Commission regulates 31 operating research and test reactors. 

Others are in the process of either removing radioactive material from the facility 

(decommissioning), or awaiting decommissioning. The decommissioning reactors are licensed to 

possess residual radioactive material, not to operate the reactor. Most research and test reactors in 

the United States are at universities or colleges. Department of Energy regulates its own 

research/test reactors.

Regulatory Oversight

Licensing

The NRC licenses research and test reactors consistent with the NRC mission. These 

licenses authorize reactor operation and possession of radioactive material. The NRC changes 

license requirements through actions that include:

• license renewals

• authorizations for decommissioning

• license terminations after completion of decommissioning

• conversions to low-enriched uranium fuel

• power upgrades

• technical specification changes

For certain technical issues and safety standards development, NRC coordinates with such 

organizations as the National Organization of Test, Research, and Training Reactors, the American 

Nuclear Society and the International Atomic Energy Agency.

Inspection

NRC staff inspect each facility periodically to ensure that licensees operate their facilities in 

accordance with the agency’s safety and security requirements and reactor-specific license 

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conditions. The NRC uses a graded approach in its inspection program, i.e., less frequent and 

detailed inspections at facilities that pose a lower risk. There are two types of inspection programs 

for operating research and test reactors.

1. For reactors licensed to operate at power levels of 2 megawatts or greater, the inspection program is 

completed annually.

2. For reactors licensed to operate at power levels below 2 megawatts, the inspection program is 

completed every two years.

Inspections of operating reactors include review of:

• Organizational structure

• Operational activities

• Reactor operator qualifications

• Review and audit functions 

• Design and design control

• Experiments

• Radiation and environmental 

protection

• Fuel handling

• Maintenance and surveillance 

activities

• Procedural controls

• Transportation

• Emergency preparedness

• Material control and accounting

• Security

Those reactors that are shut down but not actively decommissioning have an abbreviated 

inspection program completed every three years. Inspections verify the condition of the reactor and 

nuclear materials on site. This inspection program includes a review of organization and staffing, 

review and audit functions, operator requalification, radiological surveys, surveillance, emergency 

preparedness, and other areas as needed.

The NRC inspects reactors that are in the process of decommissioning for selected aspects 

of licensee’s safety programs and activities. This includes examination of: organization and staffing, 

work controls, radiation protection, plant discharge monitoring, plant configuration controls, audit 

programs, emergency preparedness, radioactive waste management, and transportation. Since 1958, 

the NRC and its predecessor, the Atomic Energy Commission, have decommissioned some 80 

research and test reactors.

If the inspection program identifies violations of requirements, the NRC takes appropriate 

enforcement action. The NRC inspection program also includes following up on allegations of 

safety or regulatory concerns.

Operator Licensing

To be licensed, research and test reactor operators must have the required knowledge, skills 

and abilities to control the reactor during both routine operations and emergencies. As part of the 

initial operator licensing process, the NRC prepares and administers both a comprehensive written 

examination and a hands-on operating test. These examinations are based on requirements in the 

Commission's regulations (10 CFR Part 55). The NRC issues six-year licenses to operators who 
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successfully complete the examination process. An operator’s license is limited to a reactor at a 

specific location and is not portable; to operate a research reactor at another location, the individual 

must train on that reactor and pass another licensing examination.

Licensed operators must maintain their expertise through a requalification program that 

covers both refresher training on material covered during initial licensing and training on new or 

modified systems, procedures and programs. Operators must pass a comprehensive written test 

every two years and an annual operating test, both of which are developed and administered by 

reactor management. The NRC reviews these examinations as part of the inspection program and 

determines if the operator meets the requalification program requirements. Every six years operators 

are required to submit an application to renew their license. As part of the application, reactor 

management must certify satisfactory participation in the requalification program.

Security

All research and test reactors are designed and operated so that material is not easily handled 

or dispersed, thus protecting against potential radiological exposure or theft of material. These 

reactors have a limited amount of radioactive material on site and therefore pose a low risk from 

radiation and the theft of nuclear material. The NRC inspects the reactor’s security and emergency 

plans, as well as its operations and design to ensure protection of public health and safety. Security 

requirements are based on a graded approach with increasing requirements for material that is more 

attractive for theft or diversion and for facilities that have larger inventories of radiological material. 

Prior to Sept. 11, 2001, all reactors had security plans or procedures and emergency plans as 

required by NRC regulations. Following the terrorist attacks on 9/11, the NRC advised licensees to 

consider taking additional security measures. Later, the NRC imposed additional security measures 

on research and test reactors by Confirmatory Action Letter. While the specifics of these measures 

are not publicly available for security reasons, in general, they include:

• enhancements in screening of personnel; 

• systems for controlling access to the facility; 

• observation of activities within the facilities;

• alarms or other devices to detect unauthorized presence; 

• operability of communication systems;

• vehicle and package searches; and 

• heightened coordination with appropriate local, state, and federal resources and law enforcement 

authorities to report unusual overflights or potential threats.

The NRC has evaluated security plans, procedures and systems and has verified, through 

inspection that appropriate security measures are in place to protect the reactors from theft or 

sabotage. The NRC continues to inspect research and test reactors to ensure compliance with all 

NRC regulations and protection of public health and safety. Further, the NRC maintains regular 

communications with other Federal agencies such as the FBI and the Department of Homeland 

Security to assess potential threats to all classes of licensees including research and test reactors.
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Research and Development Activities

A research reactor’s key output is the radiation it produces, not the very minor amount of 

heat energy produced. The most common use of this radiation (primarily neutrons and gamma rays) 

is for experiments. Some experiments require more of one type radiation than the other. The amount 

and types of radiation may be controlled by placing different types of “filters” between the reactor 

and the experiment, or positioning the experiment at different locations relative to the radioactive 

fuel in the core.

Experimenters use different types of facilities to expose the material to the required types of 

radiation. Experimental facilities include in-core radiation “baskets,” pneumatic (air-operated) tubes 

(similar to systems used at drive-through banks), and beam tubes (holes in the shielding around the 

reactor which can direct a beam of radiation to the experiment). Researchers use radiation to study 

material characteristics that cannot be readily measured otherwise. 

One widely used type of experiment is neutron scattering. Radiation from the reactor is 

directed at the material to be studied. The manner in which the radiation interacts and bounces off, 

or scatters, from the material yields information on structure and properties. Neutron scattering is an 

important tool in experiments dealing with superconductors, polymers, metals, and proteins. 

Researchers can analyze molecular structure, surfaces and interfaces, measure electronic and 

magnetic properties, stress and strain conditions, and gauge other characteristics.

Neutron radiography is another experimental technique. It is similar to medical or dental 

X-rays. These experiments are used to determine structural integrity for aerospace, automotive and 

medical components. 

Neutron activation analysis is another powerful tool used in the detection of very small 

(trace) amounts of material. It is used to measure the presence of trace elements such as 

environmental pollutants in soil, water, air, and foods with an accuracy of several parts per billion. 

Neutron activation may also be used to create new radioactive isotopes such as radiopharmaceuticals (radioactive material used in medicine) and to process silicon prior to use in 

computer chips.

Research and test reactors also are involved in medical research using neutrons for the 

treatment of cancerous tumors or making radioisotopes for research and therapy. In addition, 

research and test reactors irradiate materials used in nuclear power plants to assess how the 

materials change after exposure to radiation. These changes are important in assessing safety 

functions and in considering license extension for nuclear power plants.

Research and Test Reactor Design and Safety Features

Research and test reactors may be classified by their moderator, the material used to slow 

down the neutrons which cause the nuclear reaction. Typical moderators include water (H2O), 

heavy water (D2O), polyethylene, and graphite. 

The NRC has primarily licensed water-moderated reactors, which can be further classified 

as either pool-type or tank-type. Pool-type reactors have a core immersed in an open pool of water. 
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The pools typically have about 20 feet of water above the core to provide cooling and radiation 

shielding. At pool-type reactors, the operating core can be observed through the pool water. Tanktype reactors have a core that is in a tank with water, sealed at the top.

Reactors may also be classified by the type of fuel used, such as MTR (plate-type fuel) or 

TRIGA fuel. TRIGA fuel is unique fuel in that a moderator (hydrogen) is chemically bonded to the 

fuel.

All NRC-licensed research and test reactors have a built-in safety feature, which reduces 

reactor power during potential accidents before an unacceptable power level or temperature could 

be reached.

Research and test reactors are typically licensed by the NRC according to the total thermal 

(heat) energy produced by the reactor. These facilities range in size from 0.10 watt to 20 

megawatts-thermal. In contrast, a typical commercial nuclear power reactor is rated at 3,000 

megawatts-thermal. Because of this large difference in power generated, the consequence of an 

accident at a research and test reactor is limited when compared to a commercial power reactor. For 

this reason, research reactors’ emergency planning zones to protect the public from potential 

radiological accidents are well within owner-controlled areas -- often the boundary of the room in 

which the reactor is housed.

All research and test reactors have radiation monitors with larger facilities having monitors 

that measure particulate and gaseous releases to the environment.

Unlike power plants, research and test reactor control rooms are usually in the confinement 

or containment area where the reactor is located. Facility staff and personnel work in the reactor 

room or building during operation. Most research and test reactors are in rooms or buildings that 

have a dedicated ventilation system and all have systems that control the release of radiation.

These reactors have fail-safe shutdown systems that monitor facility conditions, and before 

an unsafe condition occurs, control rods can be used to rapidly reduce the reactor power level. 

There are also redundant systems to shut down a reactor to provide added protection of the public. 

Because of the low power levels at which research and test reactors operate, they require no 

or minimal cooling for short periods after shutdown. In addition, many of these reactors operate on 

a very limited schedule and have a limited amount of radioactive material on hand at any given 

time.

Operating Research and Test Reactors

Aerotest Operations Inc., San Ramon, CA 

Armed Forces Radiobiological Research Institute, Bethesda, MD 

Dow Chemical Company, Midland, MI

General Electric Company, Sunol, CA

Idaho State University, Pocatello, ID

Kansas State University, Manhattan, KS 

Massachusetts Institute of Technology, Cambridge, MA
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National Institute of Standards and Technology, Gaithersburg, MD

North Carolina State University, Raleigh, NC

Ohio State University, Columbus, OH

Oregon State University, Corvallis, OR

Penn State University, University Park, PA

Purdue University, West Lafayette, IN

Reed College, Portland, OR

Rensselaer Polytechnic Institute, Schenectady, NY

Rhode Island Atomic Energy Commission, Narrangansett, RI

Texas A&M University, College Station, TX (two reactors)

University of California-Davis, Sacramento, CA

University of California-Irvine, CA

University of Florida, Gainesville, FL

University of Maryland, College Park, MD

University of Massachusetts, Lowell, MA

University of Missouri, Columbia, MO 

University of Missouri, Rolla, MO

University of New Mexico, Albuquerque, NM

University of Texas, Austin, TX

University of Utah, Salt Lake City, UT

University of Wisconsin, Madison, WI

U.S. Geological Survey, Denver, CO

Washington State University, Pullman, WA

Additional information is available on our website.

May 2020