Convair X-6. Projet NEPA

La folle histoire du B 36 à propulsion nucléaire, le Convair X-6 raconté sur Wikipedia.EN

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The [Vous devez être inscrit et connecté pour voir ce lien] X-6 was a proposed experimental aircraft project to develop and evaluate a nuclear-powered jet aircraft.

The project was to use a [Vous devez être inscrit et connecté pour voir ce lien] bomber as a testbed aircraft, and though one NB-36H was modified during
the early stages of the project, the program was cancelled before the actual X-6 and its [Vous devez être inscrit et connecté pour voir ce lien]
were completed.

The X-6 was part of a larger series of programs, costing US$7 billion in all, that ran from 1946 through 1961.

Because such an aircraft's range would not have been limited by liquid jet fuel, it was theorized that nuclear-powered [Vous devez être inscrit et connecté pour voir ce lien] would be able to stay airborne for weeks at a time.

History

In May, 1946, the [Vous devez être inscrit et connecté pour voir ce lien] (NEPA) project was started by the [Vous devez être inscrit et connecté pour voir ce lien].

Studies under this program were done until May, 1951 when NEPA was replaced by the Aircraft Nuclear Propulsion (ANP) program.

The ANP program contained plans for two B-36s to be modified by Convair under the MX-1589 project.

One of the B-36s was to be used to study shielding requirements for an airborne reactor while the other was to be the X-6.

Nuclear Test Aircraft


The first modified B-36 was called the Nuclear Test Aircraft (NTA), a B-36H-20-CF (Serial Number 51-5712) that had been damaged in a tornado at [Vous devez être inscrit et connecté pour voir ce lien] on September 1, 1952.

This plane was redesignated the XB-36H, then the [Vous devez être inscrit et connecté pour voir ce lien] and was modified to carry a 3 [Vous devez être inscrit et connecté pour voir ce lien], air-cooled [Vous devez être inscrit et connecté pour voir ce lien] in its bomb bay.

The reactor, named the Aircraft Shield Test Reactor (ASTR), was operational but did not power the plane.

Water, acting as both moderator and coolant, was pumped through the reactor core and then to water-to-air heat exchangers to dissipate the heat to the atmosphere.

Its sole purpose was to investigate the effect of radiation on aircraft systems.

Le NB-36 H

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To shield the flight crew, the nose section of the aircraft was modified to include a 12-ton lead and rubber shield.

The standard windshield was replaced with one made of 6-inch–thick acrylic glass.

The amount of lead and water shielding was variable. Measurements of the resulting radiation levels were then compared with calculated levels to enhance the ability to design optimal shielding with minimum weight for nuclear-powered bombers.

The NTA completed 47 test flights and 215 hours of flight time (during 89 of which the reactor was operated) between September 17, 1955, and March 1957 over [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien].

This was the only known airborne reactor experiment by the U.S. with an operational nuclear reactor on board.

The NB-36H was scrapped at Fort Worth in 1958 when the Nuclear Aircraft Program was abandoned.

After the ASTR was removed from the NB-36H, it was moved to the [Vous devez être inscrit et connecté pour voir ce lien].

Based on the results of the NTA, the X-6 and the entire nuclear aircraft program was abandoned in 1961.

Development plans

Had the program progressed, follow-on aircraft would have been based on the successor to the B-36, Convair's swept-wing [Vous devez être inscrit et connecté pour voir ce lien].

The X-6 would have been powered by [Vous devez être inscrit et connecté pour voir ce lien] engines, utilizing a P-1 reactor.
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In a nuclear jet engine, the reactor core was used as a heat source for the turbine's air flow, instead of burning jet fuel.

One disadvantage to the design is that since the airflow through the engine was used to cool the reactor, this airflow had to be maintained even after the aircraft landed and parked.
GE built two prototype engines, which can be seen outside the [Vous devez être inscrit et connecté pour voir ce lien] in [Vous devez être inscrit et connecté pour voir ce lien].

A large, 350-foot (106.7 meter-) wide hangar was built at Test Area North, part of the National Reactor Testing Station (now part of the [Vous devez être inscrit et connecté pour voir ce lien]), [Vous devez être inscrit et connecté pour voir ce lien] to house the X-6 project, but the project was cancelled before the planned 15000-feet (4572m) runway was built.

The length was necessitated by the expected weight of the nuclear-powered aircraft.

Soviet program


In the [Vous devez être inscrit et connecté pour voir ce lien], the [Vous devez être inscrit et connecté pour voir ce lien]'s [Vous devez être inscrit et connecté pour voir ce lien] design bureau conducted a similar experiment using a [Vous devez être inscrit et connecté pour voir ce lien], which was a [Vous devez être inscrit et connecté pour voir ce lien] modified to carry an operational reactor.

Et le site JP Colliat :

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