To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Show all languages
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.

Aircraft Nuclear Propulsion

From Wikipedia, the free encyclopedia

HTRE-2, left, and HTRE-3, right, on display at the Idaho National Laboratory near Arco, Idaho
HTRE-2, left, and HTRE-3, right, on display at the Idaho National Laboratory near Arco, Idaho

The Aircraft Nuclear Propulsion (ANP) program and the preceding Nuclear Energy for the Propulsion of Aircraft (NEPA) project worked to develop a nuclear propulsion system for aircraft. The United States Army Air Forces initiated Project NEPA on May 28, 1946.[1] After funding of $10 million in 1947,[2] NEPA operated until May 1951, when the project was transferred to the joint Atomic Energy Commission (AEC)/USAF ANP.[3] The USAF pursued two different systems for nuclear-powered jet engines, the Direct Air Cycle concept, which was developed by General Electric, and Indirect Air Cycle, which was assigned to Pratt & Whitney. The program was intended to develop and test the Convair X-6, but was cancelled in 1961 before that aircraft was built.[4]

YouTube Encyclopedic

  • 1/5
    794 407
    122 226
    114 841
    669 152
    658 995
  • Nuclear Powered Bomber Documentary
  • Discovery Channel - Nuclear Airplane - Part 1 -
  • Discovery Channel - Nuclear Airplane - Part 2 -
  • Nuclear powered Planes, Trains and Automobiles
  • HOW IT WORKS: Nuclear Propulsion



Direct Air Cycle

Aircraft Reactor Experiment building at ORNL
Aircraft Reactor Experiment building at ORNL

Direct cycle nuclear engines would resemble a conventional jet engine, except that there would be no combustion chambers. The air gained from the compressor section would be sent to a plenum that directs the air into the nuclear reactor core. An exchange takes place where the reactor is cooled, but it then heats up the same air and sends it to another plenum. The second plenum directs the air into a turbine, which sends it out the exhaust. The end result is that instead of using jet fuel, an aircraft could rely on the heat from nuclear reactions for power.

The General Electric program, which was based at Evendale, Ohio, was pursued because of its advantages in simplicity, reliability, suitability and quick start ability. Conventional jet engine compressor and turbine sections were used, with the compressed air run through the reactor to be heated by it before being exhausted through the turbine.

Aircraft Reactor Experiment

The United States Aircraft Reactor Experiment (ARE) was a 2.5 MW thermal nuclear reactor experiment designed to attain a high power density for use as an engine in a nuclear-powered bomber. It used the molten fluoride salt NaF-ZrF4-UF4 (53-41-6 mol%) as fuel, was moderated by beryllium oxide (BeO), used liquid sodium as a secondary coolant and had a peak temperature of 860 °C. It operated for a 1000-hour cycle in 1954. It was the first molten salt reactor. Work on this project in the United States stopped after intercontinental ballistic missiles made it obsolete. The designs for its engines can currently be viewed at the Experimental Breeder Reactor I memorial building at the Idaho National Laboratory.

Heat Transfer Reactor Experiments


In 1955, this program produced the successful X-39 engine, two modified General Electric J47s, with heat supplied by the Heat Transfer Reactor Experiment-1 (HTRE-1).[5] The first full power test of the HTRE-1 system on nuclear power only took place in January 1956. A total of 5004 megawatt-hours of operation was completed during the test program.[6] The HTRE-1 was replaced by the HTRE-2 and eventually the HTRE-3 unit powering the two J47s. The HTRE-3 used "a flight-type shield system" and would probably have gone on to power the X-6 had that program been pursued.

Pratt and Whitney Aircraft Reactor-1

On February 5, 1957, another reactor was made critical at the Critical Experiments Facility of the Oak Ridge National Laboratory (ORNL) as part of the circulating-fuel reactor program of the Pratt and Whitney Aircraft Company (PWAC). This was called the PWAR-1, the Pratt and Whitney Aircraft Reactor-1. The purpose of the experiment was to experimentally verify the theoretically predicted nuclear properties of a PWAC reactor. The experiment was only run shortly; by the end of February 1957 all data had been taken and disassembly had begun. The experiment was run at essentially zero nuclear power. The operating temperature was held constant at approximately 675 °C (1,247 °F), which corresponds closely to the design operating temperature of the PWAR-l moderator; this temperature was maintained by external heaters. Like the 2.5 MWt ARE, the PWAR-1 used NaF-ZrF4-UF4 as the primary fuel and coolant.[7]

Indirect Air Cycle

Indirect cycling involves thermal exchange outside of the core with compressor air being sent to a heat exchanger. The nuclear reactor core would heat up pressurized water or liquid metal and send it to the heat exchanger as well. That hot liquid would be cooled by the air; the air would be heated by the liquid and sent to the turbine. The turbine would send the air out the exhaust, providing thrust.

The Indirect Air Cycle program was assigned to Pratt & Whitney, at a facility near Middletown, Connecticut. This concept would have produced far less radioactive pollution. One or two loops of liquid metal would carry the heat from the reactor to the engine. This program involved a great deal of research and development of many light-weight systems suitable for use in aircraft, such as heat exchangers, liquid-metal turbopumps and radiators. The Indirect Cycle program never came anywhere near producing flight-ready hardware.[8]

MX-1589 project

The NB-36H in a test flight, shadowed by a Boeing B-50 Superfortress
The NB-36H in a test flight, shadowed by a Boeing B-50 Superfortress

On September 5, 1951, the USAF awarded Convair a contract to fly a nuclear reactor on board a modified Convair B-36 Peacemaker[9] under the MX-1589 project of the ANP program. The NB-36H Nuclear Test Aircraft (NTA) was to study shielding requirements for an airborne reactor, to determine whether a nuclear aircraft was feasible. This was the only known airborne reactor experiment by the U.S. with an operational nuclear reactor on board. The NTA flew a total of 47 times testing the reactor over West Texas and Southern New Mexico. The reactor, named the Aircraft Shield Test Reactor (ASTR), was operational but did not power the aircraft, rather the primary purpose of the flight program was shield testing. Based on the results of the NTA, the X-6 and the entire nuclear aircraft program was abandoned in 1961.


After numerous problems the project was shut down in March 1953 only to be re-opened a year later. Technological competition with the Soviet Union (as represented by the launch of Sputnik 1), and continued strong support from the Air Force allowed the program to continue, despite divided leadership between the DOD and the AEC. The election of John F. Kennedy as President changed the course. Kennedy wrote "15 years and about $1 billion have been devoted to the attempted development of a nuclear-powered aircraft; but the possibility of achieving a militarily useful aircraft in the foreseeable future is still very remote" in his statement officially ending the ANP on March 26, 1961.[3]

See also


  1. ^ Emme, Eugene M, comp (1961), Aeronautics and Astronautics: An American Chronology of Science and Technology in the Exploration of Space, 1915–1960, Washington, DC, pp. 49–63.
  2. ^ Colon, Raul. "Flying on Nuclear, The American Effort to Built [sic] a Nuclear Powered Bomber". Archived from the original on 2 November 2008. Retrieved 2008-11-05.
  3. ^ a b "Megazone". The Decay of the Atomic Powered Aircraft Program. Worcester Polytechnic Institute. 1993. Retrieved 2008-11-05.
  4. ^ "Nuclear Powered Aircraft". Brookings Institution. Archived from the original on 2006-03-02.
  5. ^ "Chris Peters: California Tonalist Painter and Filmmaker". Retrieved 12 April 2018.
  6. ^ Thornton, G. "Introduction to nuclear propulsion- introduction and background lecture 1, feb. 26-28, 1963". NASA. NASA Technical Reports Server. Retrieved 21 September 2011.
  7. ^
  8. ^ Alvin M. Weinberg, The First Nuclear Era: The Life and Times of a Technological Fixer Sprnger Science & Business Media, 1994, ISBN 1563963582 p.106
  9. ^ Launius, Roger D. "Aeronautics and Astronautics Chronology 1950-54". Retrieved 12 April 2018.

External links

This page was last edited on 14 September 2018, at 09:22
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.