simonbp - 31/12/2005 3:09 PMAs the son of test facility engineer, They'll Find A Way....MSFC right now has a test facility consisting of a NTP engine with large heaing coils instead of fuel rods; thus allowing thermal testing without the pesky hard radiation. The new ESAS document released contains a reference to building a closed-loop testing stand in Nevada, which shouldn't be to hard considering the best thing to make it closed-loop (a vacuum chamber) is the same enviroment in which the rocket will be operating...Simon
Davros - 30/12/2005 5:07 PMI'd be in favor of this drive but the risk of enviormentalists trying to bring down the program makes me concerned about potential project cancellation. Is there a solution to this, such as a different holding and launch site for the nuclear element of the propulsion?
vanilla - 1/1/2006 11:21 AMThere is definitely going to need to be a significant effort in educating the public further about nuclear power, and it would probably be best to begin by not lumping all things nuclear together, and followed by a healthy amount of apologies for the last sixty years of nuclear mistakes. Open air testing of nuclear weapons, the drive of the AEC to produce weapons-grade plutonium and highly-enriched uranium at the exclusion of all else during the 50s and 60s, which has led to contamination problems in Washington and Colorado that persist to this day--these are examples of mistakes that need to be admitted. The list could then continue with apologies for never developing a true management plan for high-level nuclear waste and the consequences of our wasteful approach to nuclear fuels, where less than 1% of the potential nuclear energy is extracted...you get the idea.
Rocket Nut - 1/1/2006 3:45 PMI guess I don't understand your need for mea culpa and apology. We know a lot more than we did then. Heck, I flew through nuclear clouds within minutes of detonation to bring back samples for analysis...we thought the radiation doses we got then were "safe". We certainly know better now, but nobody owes me an apology or any compensation.
vanilla - 1/1/2006 5:30 PMQuoteRocket Nut - 1/1/2006 3:45 PMI guess I don't understand your need for mea culpa and apology. We know a lot more than we did then. Heck, I flew through nuclear clouds within minutes of detonation to bring back samples for analysis...we thought the radiation doses we got then were "safe". We certainly know better now, but nobody owes me an apology or any compensation. On the contrary, you are precisely the type of person I believe deserves an apology. I do not know if you have suffered from cancer in your lifetime, but if you have or do, will you not wonder if your exposures had something to do with it?
Rocket Nut - 1/1/2006 7:01 PMI guess I'm just being pragmatic about this. Whenever the Government "apologizes" for anything, it costs millions or billions to support all the lawyers who swoop down on the "victims". And yes, I would probably be one of those "victims". I would rather that money be available for the space program.
Rocket Nut - 1/1/2006 3:45 PMI guess I don't understand your need for mea culpa and apology. We know a lot more than we did then. Heck, I flew through nuclear clouds within minutes of detonation to bring back samples for analysis...we thought the radiation doses we got then were "safe". We certainly know better now, but nobody owes me an apology or any compensation. Regards,Larry
vanilla - 1/1/2006 8:44 PMThe nation, now more than ever, needs safe and economical sources of power. The space nuclear program can be a catalyst to developing those forms of power, but the current push towards NTR will be little more than several more billion dollars wasted on testing and fuel forms that have no terrestrial benefit. At the end of the process, they will say "nuclear" is too difficult, we give up. Rather, let us assert a different vision for space nuclear development that can be built, can be tested, is reasonable, and has terrestrial benefit. Our time is running out.
vanilla - 1/1/2006 8:44 PMQuoteRocket Nut - 1/1/2006 7:01 PMI guess I'm just being pragmatic about this. Whenever the Government "apologizes" for anything, it costs millions or billions to support all the lawyers who swoop down on the "victims". And yes, I would probably be one of those "victims". I would rather that money be available for the space program.Top man.
SimonShuttle - 2/1/2006 5:12 AMQuoteRocket Nut - 1/1/2006 7:01 PMI guess I'm just being pragmatic about this. Whenever the Government "apologizes" for anything, it costs millions or billions to support all the lawyers who swoop down on the "victims". And yes, I would probably be one of those "victims". I would rather that money be available for the space program.Top man.
Hotol - 2/1/2006 5:37 AMNo harm in a bit of an armisist view on this. Push for the current best option while using that as a motivation to finding a better, safer, cheaper option.Scientists shouldn't complain unless they have a viable alternative in the pipeline.
SimonShuttle - 2/1/2006 5:11 AMBut isn't the space nuclear program designed for space travel, not terrestrial benefit? Why does there have to be a clause for this to be for terrestrial benefit? That I don't understand.More over, can you give ideals on alternatives that are on the table that the general public might not be aware of.
vanilla - 2/1/2006 5:19 PMIndeed, there were actually three totally different approaches to reactor design outlined in this book, all of them with the goal of building a thorium-fueled thermal breeder reactor.One technique was to dissolve uranium sulfate into either normal (light) or preferably heavy water. The reactor was called an aqueous homogenous reactor. Imagine my surprise when I found out that two of these reactors were actually built! They also had some incredible safety characteristics. Because the water would expand when heated, which reduced neutron moderation, the reactor had a huge negative temperature coefficient. Like a mass on a stiff spring, it was essentially impossible to get the reactor to have an "excursion" into a damaging region of operation. Additionally, the decay heat (the heat generated by the decay of fission products, which remains even when the fission reaction has stopped) can be passively removed by draining the fuel into a different cooling configuration. This is simply not possible with a solid-fueled reactor, which is why a failure in the pressure vessel is so seriously. In addition, because the fuel was in a fluid, adding additional fuel as the reactor operated was easy, as was removing fission products during reactor operation. Each of these steps is terribly difficult in a solid-fueled reactor--to "reprocess" solid fuel, you essentially have to chop it up, dissolve it in acid, and then separate everything chemically. Basically you can only reprocess liquid fuel--if you have solid fuel you have to make it liquid--this reactor already had liquid fuel.But despite all these advantages, the aqueous homogeneous reactor had a serious drawback. By using water at the solvent/moderator, you were limited to rather low temperatures and high pressures by the characteristics of the water itself. The next reactor in the book had all the advantages without this disadvantage--the molten fluoride reactor.
Chris Bergin - 2/1/2006 12:12 PMThorium-fueled thermal breeder reactor, and more so the molten fluoride reactor - do we have any available web-based resources on these concepts for further learning? Also allow me to forward this thread to a couple of MSFC guys who are pretty savvy on such propulsion/energy concepts.