Too much mass would be required for the shielding if the plane was flown by humans...
On the other hand, for unmanned aircraft, it's very plausible
After more than six decades of research, the first atom-powered airplane is cleared for takeoff. Although details of the project remain classified, a description of this remarkable aircraft has begun to emerge from technical conferences and declassified engineering studies. The plane will be both familiar and unique. Familiar in that it will resemble a Northrop Grumman Global Hawk, the bulbous-nosed unmanned aerial vehicle (UAV) that the U.S. Air Force has used to track enemy movements in Afghanistan and Iraq. Unique because its nuclear reactor is unlike any other. Rather than split heavy elements or fuse light atoms--as in fission and fusion reactors--it will use what is known as a triggered isomer reaction. If this new powerplant, called a quantum nucleonic reactor, performs as scientists expect, its effect on the aircraft industry may prove as revolutionary as the introduction of the jet engine.
A solar cell or engine-mounted generator sends electricity to run a small X-ray machine. The X-rays strike a block of hafnium-178, triggering a drop in the energy levels within the nucleus of the hafnium atoms. This change in energy levels is accompanied by the release of a burst of gamma radiation.
Originally posted by sardion2000
Well the Global Hawk is not really powered by a nuclear reactor. It's powered by a type of Quantum battery.
A solar cell or engine-mounted generator sends electricity to run a small X-ray machine. The X-rays strike a block of hafnium-178, triggering a drop in the energy levels within the nucleus of the hafnium atoms. This change in energy levels is accompanied by the release of a burst of gamma radiation.
If this concept works as well as I think it will, we could have a whole new era of space flight on our hands(Doesn't that sound familiar). BTW I have also read somwhere that this type of reaction produces 60x more energy coming out then is used to trigger a drop in hafnium178 energy levels. Can anyone confirm this?
Here are some more links on the subject..
www.spacedaily.com...
www.newscientist.com...