Posted on 01/11/2002 6:34:50 AM PST by techcor
The American Drive
So, what is "The American Drive"? It is a rocket engine based on americium-242m , the most powerful fuel this side of fusion or anti-matter. The American Drive
This is based on an article from about a year ago called "Two Weeks to Mars" . Some points from the article are that americium-242m is about 100 times as powerful as plutonium and one gram is about equal in power to about one ton of rocket fuel. Some people are already working on the problem of production of the fuel (americium production) . Think of it as a natural "ion" drive but more powerful. I'm naming it after the amercium fuel which was named after the Americas.
Now, some will say this is too revolutionary to use as a rocket fuel. That is why I believe it will first be implemented in a process to reduce nuclear waste. I base this premise on an article from a few years ago called "Putting Nuclear Waste to Work" (Pop. Mech. 1998). Basically, Dr. Claudio Filippone has developed a new type of reactor called a Nuclear Power Turbo-Reciprocating Engine (NPTRE). It is a piston engine with a special super-caviation chamber in which water is flashed into steam by the fission reaction. Other methods of transmutation are being developed but this way seems the most efficient. From the article:
"And that's not all. When all of the heat and motion is accounted for, the NPTRE will achieve a thermal efficiency of 56%. By comparison, a conventional reactor operates with a thermal efficiency of 30% to 33%."
I see the future as this:
1. Americium developed for nuclear waste transmutation.
2. New nuclear reactors developed that are smaller and more powerful.
3. Rocket engines based on this element that will be faster than anyone would have previously believed.
4. Flying cars. Ok, so this one probably wont happen . But I really, really, want one.
Political implications? Well, every major liberal from Gore to Nader has trashed nuclear power as being too dangerous because of radioactive waste that will last for ten thousand years. But wait! Didn't the previous administration have a problem of almost selling "slightly" radioactive nickel that had been transmutated from a higher radioactive state? Gosh! Liberals wouldn't lie to the American public on such a serious subject would they ? On the other hand Republicans have come out for nuclear power.
This can also be a powerful tool in building relations with Russia, Japan, and France. Especially Russia. They are even more desperate than we are to clean up nuclear waste, they are a space power, and Russia and the U.S. are looking for a way to reduce nuclear weapons.
Americium and Californium are currently used as alpha sources in smoke detectors. The NRC has waived Byproduct licenses for these little uses, but usually, anything from a reactor is regulated. This sounds like a "burner" application, where something with a short halflife and a high specific activity is used as a heat source. Strontium 90 was used in a space power application for the early SNAP satellite battery.
But I think that there are enough objections to this scheme that we will probably never see it in use.
One thing to remember is that the Cassimi(sp?) satellite was sent up a couple of years ago with 73lbs. of plutonium on it. The same rocket might have been propelled with only .73lbs. of Am242m. I'd still like to tie it in with nuclear waste disposal to make more of a market for it. I mean, who can argue with cleaning up nuclear waste?
Heh--the "Greens" can argue with anything.
Remember--having a basis in scientific facts aren't part of their thought repertoire.
Hang in there--remember most of the techies on FR are probably either off at work or in class. I only saw this before evening because I came home for lunch.
It sounds very expensive to produce this fuel. I wonder whether any cost estimates have been made.
Yeah, I know. I was just bumping it a little. Kind of reminds me when a Freeper posted that he was going to change his screen name to Death of Threads because every time he posted that ended it. Got a grin from that one. I'll give it a rest and check back in several hours. Just thought the timing was good considering they just announced a selection on nuclear waste storage. Hey, you never answered my question about your screen name.
Californium in smoke detectors? Gawd, I hope not. 252-Cf is one helluva neutron source. You don't want neuts in a smoke detector. Besides that, its tough to make (you're talking about something like a 14n-capture reaction in uranium, and thus is bloody expensive. Last I heard, ORNL was selling it for something like $50 per microgram. And since the neutron emission rate is about 2.8 million n/sec for a microgram, I don't think we want that in smoke detectors. Americium is the material of choice in that application, I think.
Extremely efficient nuclear fuel could take man to Mars in just two weeks
Scientists at Ben-Gurion University of the Negev have shown that an unusual nuclear fuel could speed space vehicles from Earth to Mars in as little as two weeks. Standard chemical propulsion used in existing spacecraft currently takes from between eight to ten months to make the same trip. Calculations supporting this conclusion were reported in this month's issue of Nuclear Instruments and Methods in Physics Research A (455: 442-451, 2000) by Prof. Yigal Ronen, of BGU's Department of Nuclear Engineering and graduate student Eugene Shwagerous.
In the article, the researchers demonstrate that the fairly rare nuclear material americium-242m (Am-242m) can maintain sustained nuclear fission as an extremely thin metallic film, less than a thousandth of a millimeter thick. In this form, the extremely high-energy, high-temperature fission products can escape the fuel elements and be used for propulsion in space. Obtaining fission-fragments is not possible with the better-known uranium-235 and plutonium-239 nuclear fuels: they require large fuel rods, which absorb fission products.
Ronen became interested in nuclear reactors for space vehicles some 15 years ago at a conference dedicated to this subject. Speaker-after-speaker stressed that whatever the approach, the mass (weight) of the reactor had to be as light as possible for efficient space travel. At a more recent meeting, Prof. Carlo Rubbia of CERN (Nobel Laureate in Physics, 1984) brought up the novel concept of utilizing the highly energetic fragments produced by nuclear fission to heat a gas; the extremely high temperatures produced would enable faster interplanetary travel.
To meet the challenge of a light nuclear reactor, Ronen examined one element of reactor design, the nuclear fuel itself. He found at the time that of the known fission fuels, Am-242m is the front-runner, requiring only 1 percent of the mass (or weight) of uranium or plutonium to reach its critical state. The recent study examined various theoretical structures for positioning Am-242m metal and control materials for space reactors. He determined that this fuel could indeed sustain fission in the form of thin films that release high-energy fission products. Moreover, he showed how these fission products could be used themselves as a propellant, or to heat a gas for propulsion, or to fuel a special generator that produces electricity.
"There are still many hurtles to overcome before americium-242m can be used in space," Ronen says. "There is the problem of producing the fuel in large enough quantities from plutonium-241 and americium-241, which requires several steps and is expensive. But the material is already available in fairly small amounts. In addition, actual reactor design, refueling, heat removal, and safety provisions for manned vehicles have not yet been examined.
"However, I am sure that americium-242m will eventually be implemented for space travel, as it is the only proven material whose fission products can be made available for high speed propulsion. Indeed, Carlo Rubbia has also recognized that this is the most probable fuel that will be getting us to Mars and back. I think that we are now far enough advanced to interest international space programs in taking a closer look at americium-based space vehicles.
As for cost the, the americium production link should lead to a memo by a scientist that he thinks a process could be developed that would have a final output of half americium242 and half americium 242m. That's why it would be great if the decay byproduct of the americium 242 (Neptonium something or other) could be used to "cool" nuclear waste creating a very useful market for it.
They are still thinking in Apollo Program mode.
There and back. They are boxing themselves in.
Opening up Mars should require opening up the minds of the planners. Think a little outside the box.
That's harder than developing a new system, IMO.
gas-core nuclear propulsion
Excellent! That's the sort of thing I wanted to see in the replies. Any more info on those? As for the "Greens"... they are exactly why I'm trying to tie in the power from nuclear waste part.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.