page_title: Aircraft Reactor Experiment
section_title: Development Program
hierarchical_section_title: Aircraft Reactor Experiment / Development Program
caption_attribution_description: English: Building plan of the Aircraft Reactor Experiment Building from page 233 of ORNL-1845
context_page_description: The Aircraft Reactor Experiment was an experimental nuclear reactor designed to test the feasibility of fluid-fuel, high-temperature, high-power-density reactors for the propulsion of supersonic aircraft. It operated between November 8-12, 1954 at the Oak Ridge National Laboratory with a maximum sustained power of 2.5 megawatts, and generated a total of 96 MW-hours of energy.
  The ARE was the first reactor to use circulating molten salt fuel. The hundreds of engineers and scientists working on ARE provided technical data, facilities, equipment, and experience that enabled the broader development of molten salt reactors as well as liquid metal cooled reactors.
context_section_description: The heat exchanger chamber took up significantly more space than the reactor and dump tank chambers. 
  The ambitious goals and military importance of the ANP catalyzed a significant amount of research and development of complex systems in challenging high-temperature, high-radiation environments. 
  Corrosion and hot sodium handing studies began in 1950. 
  Investigations of the engineering and fabrication problems involved in handling molten fluoride salts began in 1951 and continued through 1954. Natural-convection corrosion test loops were operated to down-select suitable material and fuel combinations. Subsequent studies in forced-circulation test loops established means to minimize corrosion and mass transfer.
  Development of pumps, heat exchangers, valves, pressure instrumentation, and cold traps spanned from late 1951 to summer 1954. Much of the work was based on extensive experience at lower temperature from Argonne National Laboratory and the Knolls Atomic Power Laboratory. 
  Techniques had to be developed concerning the construction, preheating, instrumentation, and insulation of reliable leak-tight high-temperature circuits made of Inconel. They found that all-welded construction was necessary. 
  In all, equipment development in support of high-temperature leak-tight operation lasted about 4 years.
  The ARE Hazard Summary Report was issued on November 24, 1952. 
  A low-temperature critical mockup of the reactor was assembled to verify the calculation models. The BeO moderator blocks were fitted with straight tubes filled with a powder mixture to simulate the fuel. Critical mass, regulating rod worth, safety rod worth, neutron flux distributions, and reactivity coefficients of a wide variety of materials were measured.
  Construction of the test facility building began on July 6, 1951.
caption: Building plan of the Aircraft Reactor Experiment Building
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