Advanced Test Reactor

Advanced Test Reactor
Idaho National Laboratory · CC BY 2.0 · source
Name	Advanced Test Reactor
Location	Idaho National Laboratory
Country	United States
Operator	Idaho National Laboratory
Status	Operational
Constructed	1970s
First criticality	1977
Type	Research reactor
Power	250 MW(th)

Advanced Test Reactor

The Advanced Test Reactor is a research reactor located at the Idaho National Laboratory near Idaho Falls, Idaho, constructed in the 1970s to support nuclear fuel and materials testing for the United States Department of Energy, the Nuclear Regulatory Commission, and diverse partners including United States Navy nuclear propulsion programs, national laboratories, and private industry. It provides high neutron flux environments for irradiation experiments used by institutions such as Oak Ridge National Laboratory, Los Alamos National Laboratory, Argonne National Laboratory, and international collaborators like Cadarache and Jülich Research Centre. The facility connects to broader programs and agreements involving organizations such as the Atomic Energy Commission predecessors, the Office of Nuclear Energy, and contractors including Battelle Memorial Institute and Fluor Corporation.

Overview

The reactor resides within the Idaho National Engineering Laboratory complex and contributes to initiatives tied to Advanced Reactor Concepts, Naval Nuclear Propulsion Program, and fuel qualification efforts for entities like Westinghouse Electric Company, GE Hitachi Nuclear Energy, and Framatome. ATR supports cooperative research with universities such as the Massachusetts Institute of Technology, University of California, Berkeley, University of Michigan, Pennsylvania State University, and international universities including Imperial College London and University of Tokyo. The facility’s role intersects with programs overseen by agencies including the Defense Threat Reduction Agency, National Aeronautics and Space Administration, and the National Nuclear Security Administration.

Design and Specifications

The reactor features a unique serpentine core geometry developed to produce high-volume, high-intensity neutron flux regions used for materials irradiation; its design lineage traces to experimental reactors informed by work at Argonne National Laboratory and theoretical studies by researchers associated with Oak Ridge National Laboratory. ATR operates at a nominal thermal power of approximately 250 MW(th) and employs light water coolant and light water moderator with heavy reflector configurations influenced by practices at Calder Hall and Dounreay research sites. Fuel assemblies and control systems derive from engineering standards promulgated in collaboration with contractors such as General Electric and design authorities parallel to those engaged with Savannah River Site reactors. Instrumentation and metrology systems integrate technologies used by Sandia National Laboratories, Los Alamos National Laboratory, and standards aligned with American Nuclear Society guidelines. The core includes multiple flux traps and test positions comparable in function to irradiation rigs used at High Flux Isotope Reactor and BR2.

Operational History

First achieving criticality in the late 1970s, ATR has supported decades of irradiation campaigns, lifecycle testing, and failure-mode analyses for fuel types examined at Hanford Site and prototype programs related to projects at Three Mile Island and Davis-Besse Nuclear Power Station. Operational management transitioned through contractors and oversight entities including Bechtel National, Battelle Energy Alliance, and U.S. Department of Energy field offices, while collaborations extended to international agencies such as the International Atomic Energy Agency. The reactor has been involved in milestone programs tied to the Naval Reactors mission and contributed data to licensing efforts for new reactors evaluated by the Nuclear Regulatory Commission. ATR’s operating record includes periodic outages for refueling and refurbishment, coordinated with safety reviews similar to those conducted at Cadarache and SCK CEN facilities.

Research and Testing Programs

ATR supports irradiation testing for advanced fuels including metal, oxide, and carbide fuels investigated by teams from Idaho State University, Purdue University, University of Wisconsin–Madison, and industrial partners such as Rolls-Royce and Toshiba. Research scopes include materials degradation studies linked to programs at Sandia National Laboratories, isotope production relevant to projects at Brookhaven National Laboratory and Los Alamos National Laboratory, and fusion materials testing associated with initiatives at ITER and fusion research centres like JET. Test articles include instrumented capsules, loop experiments for coolant chemistry studies akin to those at Oak Ridge National Laboratory's reactors, and joint projects with organizations such as Electric Power Research Institute and National Institute of Standards and Technology. ATR has enabled irradiation-assisted stress corrosion cracking studies, transient testing protocols comparable to campaigns run at Petten and HFR Petten, and production of medical isotopes similar to outputs from Canadian Nuclear Laboratories.

Safety and Regulatory Aspects

Safety and oversight involve compliance frameworks modeled on standards used by the Nuclear Regulatory Commission, reviews coordinated with the Defense Nuclear Facilities Safety Board, and environmental assessments akin to those prepared for facilities at Savannah River Site and Hanford Site. Emergency preparedness interfaces with local authorities in Bonneville County, Idaho and state agencies such as the Idaho Department of Environmental Quality. Radiological protection and health physics practices align with protocols used by Los Alamos National Laboratory and guidance from agencies like the Centers for Disease Control and Prevention and the Environmental Protection Agency. Security measures and safeguards incorporate approaches used by Naval Reactors and international safeguards coordinated with the International Atomic Energy Agency.

Decommissioning, Upgrades, and Future Plans

Planned modernization and capability sustainment initiatives parallel upgrade programs at facilities like High Flux Isotope Reactor and BR2, involving modernization of instrumentation, replacement of aging systems by contractors experienced in projects for Bechtel and Fluor, and potential fuel conversion efforts resonant with campaigns overseen by the National Nuclear Security Administration. Long-term disposition planning references decommissioning frameworks applied at Shippingport Atomic Power Station and lessons from decommissioning at Winfrith and Chalk River Laboratories. Future research agendas include support for advanced reactor licensing pursued by companies such as NuScale Power, TerraPower, and X-energy, expanded isotope production partnerships with healthcare stakeholders, and continued contributions to international materials research programs associated with Euratom and multinational consortia.

Category:Idaho National Laboratory Category:Research reactors