Aircraft Nuclear Propulsion
Encyclopedia
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 Force initiated Project NEPA on May 28, 1946. After funding of $10 million in 1947, NEPA operated until May 1951, when the project was transferred to the joint Atomic Energy Commission
(AEC)/USAF 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 intended to develop and test the Convair X-6
, but was cancelled in 1961 before that aircraft was built.
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.
The US 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 US stopped after ICBMs made it obsolete. The designs for its engines can currently be viewed at the EBR-I memorial building at the Idaho National Laboratory
.
In 1955, this program produced the successful X-39 engine, two modified General Electric J47
s with heat supplied by the Heat Transfer Reactor Experiment-1 (HTRE-1). 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. 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.
. 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 exchanger
s, liquid-metal turbopump
s and radiator
s. The Indirect Cycle program never came anywhere near producing flight-ready hardware.
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 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.
Nuclear aircraft
A nuclear aircraft is an aircraft powered by nuclear energy. Research into them was pursued during the Cold War by the United States and the Soviet Union as they would presumably allow a country to keep nuclear bombers in the air for extremely long periods of time, a useful tactic for nuclear...
. The United States Army Air Force initiated Project NEPA on May 28, 1946. After funding of $10 million in 1947, NEPA operated until May 1951, when the project was transferred to the joint Atomic Energy Commission
United States Atomic Energy Commission
The United States Atomic Energy Commission was an agency of the United States government established after World War II by Congress to foster and control the peace time development of atomic science and technology. President Harry S...
(AEC)/USAF ANP. The USAF pursued two different systems for nuclear powered jet engines, the Direct Air Cycle concept which was developed by General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
, and Indirect Air Cycle which was assigned to Pratt & Whitney
Pratt & Whitney
Pratt & Whitney is a U.S.-based aerospace manufacturer with global service operations. It is a subsidiary of United Technologies Corporation . Pratt & Whitney's aircraft engines are widely used in both civil aviation and military aviation. Its headquarters are in East Hartford, Connecticut, USA...
. The program was intended to develop and test the Convair X-6
Convair X-6
-See also:*Project Pluto*Project Rover*NERVA*WS-125Comparable aircraft* Tupolev Tu-119-External links:* original published on Aviation History, March 1995.* Section devoted to NB-36H...
, but was cancelled in 1961 before that aircraft was built.
Direct Air Cycle program
Evendale, Ohio
Evendale is a village in Hamilton County, Ohio, United States. The population was 3,090 at the 2000 census.Evendale was the home of John Van Zandt, a participant in the Underground Railroad....
, was pursued because of its advantages in simplicity, reliability, suitability and quick start ability. Conventional jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...
compressor
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
and turbine
Turbine
A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they move and...
sections were used, with the compressed air run through the reactor itself to heat it before being exhausted through the turbine.
The US Aircraft Reactor Experiment (ARE) was a 2.5 MW thermal
Thermal reactor
A thermal reactor is a nuclear reactor that uses slow or thermal neutrons. Most power reactors are of this type. These type of reactors use a neutron moderator to slow neutrons until they approach the average kinetic energy of the surrounding particles, that is, to reduce the speed of the neutrons...
nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
experiment designed to attain a high power density
Power density
Power density is the amount of power per unit volume....
for use as an engine in a nuclear powered bomber. It used the molten fluoride salt NaF
Sodium fluoride
Sodium fluoride is an inorganic chemical compound with the formula NaF. A colorless solid, it is a source of the fluoride ion in diverse applications. Sodium fluoride is less expensive and less hygroscopic than the related salt potassium fluoride....
-ZrF4
Zirconium(IV) fluoride
Zirconium fluoride is an inorganic chemical compound. It is a component of ZBLAN fluoride glass. It is insoluble in water. It is the main component of fluorozirconate glasses....
-UF4 (53-41-6 mol%) as fuel
Nuclear fuel
Nuclear fuel is a material that can be 'consumed' by fission or fusion to derive nuclear energy. Nuclear fuels are the most dense sources of energy available...
, was moderated
Neutron moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235....
by beryllium oxide
Beryllium oxide
Beryllium oxide , also known as beryllia, is an inorganic compound with the formula BeO. This colourless solid is a notable electrical insulator with a higher thermal conductivity than any other non-metal except diamond, and actually exceeds that of some metals. As an amorphous solid, beryllium...
(BeO), used liquid sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
as a secondary coolant
Coolant
A coolant is a fluid which flows through a device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, and chemically inert, neither causing nor...
and had a peak temperature of 860 °C. It operated for a 1000-hour cycle in 1954. It was the first molten salt reactor
Molten salt reactor
A molten salt reactor is a type of nuclear fission reactor in which the primary coolant, or even the fuel itself is a molten salt mixture...
. Work on this project in the US stopped after ICBMs made it obsolete. The designs for its engines can currently be viewed at the EBR-I memorial building at the Idaho National Laboratory
Idaho National Laboratory
Idaho National Laboratory is an complex located in the high desert of eastern Idaho, between the town of Arco to the west and the cities of Idaho Falls and Blackfoot to the east. It lies within Butte, Bingham, Bonneville and Jefferson counties...
.
In 1955, this program produced the successful X-39 engine, two modified General Electric J47
General Electric J47
|-Specifications :-Nuclear-powered version – The X39:In the 1950s, interest in the development of nuclear-powered aircraft led GE to experiment with two nuclear-powered gas turbine designs, one based on the J47, and another new and much larger engine called the X211.The design based on the J47...
s with heat supplied by the Heat Transfer Reactor Experiment-1 (HTRE-1). 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. 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, ConnecticutMiddletown, Connecticut
Middletown is a city located in Middlesex County, Connecticut, along the Connecticut River, in the central part of the state, 16 miles south of Hartford. In 1650, it was incorporated as a town under its original Indian name, Mattabeseck. It received its present name in 1653. In 1784, the central...
. 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 exchanger
Heat exchanger
A heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact...
s, liquid-metal turbopump
Turbopump
A turbopump is a gas turbine that comprises basically two main components: a rotodynamic pump and a driving turbine, usually both mounted on the same shaft, or sometimes geared together...
s and radiator
Radiator
Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, and electronics...
s. The Indirect Cycle program never came anywhere near producing flight-ready hardware.
MX-1589 project
On September 5, 1951, the USAF awarded Consolidated-Vultee a contract to fly a nuclear reactor onboard a modified Convair B-36Convair B-36
The Convair B-36 "Peacemaker" was a strategic bomber built by Convair and operated solely by the United States Air Force from 1949 to 1959. The B-36 was the largest mass-produced piston engine aircraft ever made. It had the longest wingspan of any combat aircraft ever built , although there have...
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 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.
See also
- Nuclear aircraftNuclear aircraftA nuclear aircraft is an aircraft powered by nuclear energy. Research into them was pursued during the Cold War by the United States and the Soviet Union as they would presumably allow a country to keep nuclear bombers in the air for extremely long periods of time, a useful tactic for nuclear...
- Convair X-6Convair X-6-See also:*Project Pluto*Project Rover*NERVA*WS-125Comparable aircraft* Tupolev Tu-119-External links:* original published on Aviation History, March 1995.* Section devoted to NB-36H...
- Project PlutoProject PlutoProject Pluto was a United States government program to develop nuclear powered ramjet engines for use in cruise missiles. Two experimental engines were tested at the United States Department of Energy Nevada Test Site in 1961 and 1964.-History:...
- Project RoverProject RoverProject Rover was an American project to develop a nuclear thermal rocket. The program ran at the Los Alamos Scientific Laboratory from 1955 through 1972 and involved the Atomic Energy Commission, and NASA. The project was managed by the Space Nuclear Propulsion Office.Nuclear reactors for the...
- WS-110AWS-110AWS-110A was a project by the United States Air Force in the 1950s to develop a supersonic bomber aircraft capable of delivering nuclear weapons. Proposals for such an aircraft were submitted by Boeing and North American Aviation...
- Georgia Nuclear Aircraft LaboratoryGeorgia Nuclear Aircraft LaboratoryThe Georgia Nuclear Aircraft Laboratory, also known as AFP No. 67, for Air Force Plant 67 was a United States Air Force test facility located in the Dawson Forest in Dawsonville, Georgia. It was the site of Lockheed's lab for investigating the feasibility of nuclear aircraft...
- Molten salt reactorMolten salt reactorA molten salt reactor is a type of nuclear fission reactor in which the primary coolant, or even the fuel itself is a molten salt mixture...
- Liquid fluoride thorium reactorLiquid fluoride thorium reactorThe liquid fluoride thorium reactor is a thermal breeder reactor which uses the thorium fuel cycle in a fluoride-based molten salt fuel to achieve high operating temperatures at atmospheric pressure....
- Experimental Breeder Reactor IExperimental Breeder Reactor IExperimental Breeder Reactor I is a decommissioned research reactor and U.S. National Historic Landmark located in the desert about southeast of Arco, Idaho. At 1:50 pm on December 20, 1951 it became the world's first electricity-generating nuclear power plant when it produced sufficient...
- NERVANERVANERVA is an acronym for Nuclear Engine for Rocket Vehicle Application, a joint program of the U.S. Atomic Energy Commission and NASA managed by the Space Nuclear Propulsion Office until both the program and the office ended at the end of 1972....
External links
- Dreams of Nuclear Flight - The NEPA and ANP programs
- The Bureau of Atomic Tourism
- Nuclear HTRE propulsion
- "A Scientist Preview The First Atomic Airplane" by Gerald Wendt for 1951 a very good article with illustrations on the subject of using an atomic reactor to power an aircraft