Aircraft Nuclear Propulsion

Aircraft Nuclear Propulsion (ANP) was a United States Air Force program which worked to develop a nuclear propulsion system for aircraft. It was the follow-on to the USAF's Nuclear Energy for the Propulsion of Aircraft (NEPA). NEPA was launched in May, 1946, and operated until May 1951, when the efforts were transferred to the ANP. 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 ultimately intended to result in the development and flight testing of the Convair X-6, but was cancelled in 1961 before that aircraft was built. [http://web.archive.org/web/20060302180919/http://www.radiationworks.com/flyingreactor.htm "Nuclear Powered Aircraft", quoting Brookings Institute text] ]

Direct Air Cycle program

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 itself to heat it before being exhausted through the turbine. This program produced the successful X-39 engine, two modified GE J47s with heat supplied by the Heat Transfer Reactor Experiment-1 (HTRE-1). 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.

Indirect Air Cycle program

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 turbo pumps and radiators. The Indirect Cycle program never came anywhere near producing flight-ready hardware.

MX-1589 project

The ANP program required that Convair modify two B-36s under the MX-1589 project. One of these, the Nuclear Test Aircraft (NTA), was an NB-36H modified 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 plane, 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.

ee also

* Project Pluto
* Georgia Nuclear Aircraft Laboratory

References

External links

* [http://www.megazone.org/ANP/ The Decay of the Atomic Powered Aircraft Program] .

* [http://www.aviation-history.com/articles/nuke-american.htm Flying on Nuclear, The American Effort to Built a Nuclear Powered Bomber] .