This is revolutionary & could vastly increase range & nicely drop our demand for Mid East oil According to Pop Mechanics mag the DOD & Sandia labs are working on a small halfnium powered reactor. a small Xray machine heats up a block of halfnium which has a half life of only 31 years & cannot be used to make nuclear weapons. The Halfnium block then sends out Gamma rays which heat up a heat exchanger which then forces hot air into a jet engine replicating the jet fuel Ox mixture. The DOD plans to test this system out on their robotic Global hawk surveillance craft. WOnder if they can eventually adapt if for automotive use ?
So, uh, what happens when this nuclear bird malfunctions for some reason and plows into a house or community? Contamination?
Yep sounds like BS to me All though many years ago some bright spark came up with the idea of putting Hydrogen in the air ships ... when they could have used nice and safe Helium! Come on man kind, lets kill ourselves. Just imagine the excitement this anoucement would cause amongst the terrorist camps ... Pete
over the yrs i have regarded PM to be mostly humor, with a bit of something closely resembling truth.
Yeah, first thing I think of is. OK, what happens when it crashes. Since, black boxes are designed to be indestructible, and yet often are destroyed (even though they have relatively low mass and are put in the rear of the plane and are armored) how would one protect a reactor from releasing its fissionable material... Could you just imagine the uproar of the "don't use it near me" attitude. It wouldn't even compare to the uproar over the Concorde when it was first introduced. But, at some point, we will figure out how to build a reactor that can safe itself. Maybe it works like a reverse airbag, that on sensing high G's it floods the fissionable material with some kind of anti-radiation epoxy that instantly sets itself and hardens to make the material inert. Who knows. But, using nuclear technology for vehicles (think advanced fusion) is on its way one day. Fuel cells will be perfected first most likely.
Seems the halfnium is not as dangerous as other materials like plutonium & has a much shorter half life of only 31 years. Also halfnium is not suitable for nuclear weapons as it cannot support achain reaction which a bomb requires. What do you think is safer for the world. Nuclear airplanes or constant war over oil ?
My honest opinion is that by the time ANY NEW technology is certified for aviation that the mega-(world)-war over oil will have already happened. If some whiz bang tech was invented tomorrow, it would enter into service first as generators then trains/car and lastly into aircraft. It would take about 30 years for it to make it into aircraft if it were invented in a lab tomorrow. But, that's based on past examples of how slow basic (airframe/engine) technology gets updated in aviation.
Couple of points: If it has a half-life of 31 years - that would actually put the full life of the element at 31, 15.5, 7.x, 3.x, 1.5x, .7x, .35x, etc. Which really means the elements full life is around 61 years or so. I suppose it would be possible for directed gamma rays - with specific shielding. I would have to see more specs to determine what risks on this would be... It seems like this depends heavily on Gmr production which would not be good for passengers - for any lenght of time. There have already been other aircraft with Atomic Elements for propulsion.. Ie. There is currently a spaceship hurtling across our galaxy that is propelled by plutonium... Of course this is unmanned and in space. I would be very possible to shield/protect if this was a "real" application use - in case of a wreckage - The newer applications of nuclear powerplants in the US are much more safe than what coal or oil plants are, as well as our Nuclear Subs employ the same saftey precautions. This is not something that I worry about - in todays applications. (The 60, 70s - was a different story).
The USAF spent millions on a nuclear powered B-36 bomber project back in the 50s. The aircraft itself was never actually nuclear powered; the project never got that far. The first step was to get a working nuclear reactor installed in a flying aircraft. That's about as far as they got. Here's the full story: http://americanhistory.about.com/library/prm/blwingedatom1.htm
Two inches of lead will reduce gamma radiation to 1/10 of what it was to start. What is Halfnium? Or do you mean hafnium? If you mean the latter there's not enough to go around, so this idea can be scrapped.
Oops , it is Hafnium. Guess we better fly out to the asteroid belt & stock up if theres not enough to go around here on Earth
You sure it was DOD? Sandia is of course a DOE lab, and does primarily DOE-related work... The public might try having a go searching for this here: http://www.sandia.gov/news-center/index.html ...assuming Sandia has actually published somthing public on it. --Mike
Guess they could scavenge (or likely have scavenged) the hafnium from all the naval nuclear cores that have been decommissioned: the control rods are hafnium (which is a terrific neutron absorber).