The atomic airplane would weigh 300 tons, stretch 205 feet long and measure 136 feet from wingtip to wingtip. Big, but smaller than a 747.
The plane was a joint project of the Air Force and the Atomic Energy Commission that began in in 1946. The goal was to come up with a practical airplane that could fly 15,000 miles without having to land.
They built a big earth-shielded hangar for the plane. The first photo shows construction and the completed hangar, which last I knew was being used for manufacturing tank armor.
That the plane’s hangar is being used for some other purpose is a clue about the plane itself. They did successfully test twin nuclear engines, but at 30 feet high they were a tad big for airplanes. Miniaturization might have been possible, eventually, if the project weren’t shelved in the early 60s. Technological problems, such shielding the pilots, weren’t what killed it. Fears that such a plane would eventually crash, making the accident site uninhabitable, brought it down before it ever went up, and before a prototype had been built.
Today, you can see the two Heat Transfer Reactor Experiment reactors, used in the effort to build an atomic-powered airplane. They sit in front of the Experimental Breeder Reactor-I Atomic Museum at the site near Arco.
By the way the NRTS became the Idaho National Engineering and Environmental Laboratory (INEEL), then the Idaho National Lab (INL). It retains the latter designation today. Many people in eastern Idaho just call it The Site, rather than keep up with the acronyms.
Information about the nuclear plane comes largely from Susan Stacy’s book Proving the Principle, a History of the National Engineering and Environmental Laboratory, 1949-1999.