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Comment Re:Wrong Focus (Score 1) 132

Note that it's technically possible to have something like this with a slow reactor; you could for example use steam as a moderator, which will transmit a reasonable proportion of near infrared through it (the hotter you can run your fuel particles, the better transmission you'll get). But not only will you lose some light, but just the simple act of neutron moderation is a very heat-intensive process, meaning big radiators if you want big power (not to mention that the moderator itself for such a slow reactor is also far heavier than the core). The whole point of my variant is to avoid the moderator and avoid the ship having to ever capture anything but incident heat lost due to generation, transmission, reflection, etc losses.

One possibility for a slow reactor, albeit only directly applicable to the rocket mode above, is to have your propellant be your moderator, absorbing both IR and moderating fast neutrons. The fact that it's heating then becomes irrelevant (actually an advantage), since you're dumping it out the nozzle for thrust. If one wanted mission flexibility in such a scenario you could have such a moderator-ejecting rocket mode used to get to orbit, and then switch to retaining the moderator once in orbit and cooling it instead in order to make use of the fission fragment operating mode.

But a fast reactor would obviously be highly preferable so you don't have to worry about a moderator at all. :) I'm just pointing the above out because slow reactor versions have already been simulated.

Comment Re:Wrong Focus (Score 1) 132

Wait a minute, no, I entered it right into the calculator the first time around. Argh, this interface is confusing. Radiative equilibrium for Tunsten at its melting point 3300C according to the calculator is 92MW/m. A "cool" 1200C radiative temperature according to the calculator 2,6MW/m. According to the calculator, 10kW/m is about 380C.

Comment Re:I still wonder how people in the Internet world (Score 1) 120

Because reaching your customers directly is hard. If it was easy, nobody would sign up for these services. Its especially hard for a small business like these- you expect them not only to be master craftsmen, but master marketers, master SEOs, and master businessmen as well? And do all of it in the span of a working day? Not exactly realistic. Now alternatives competing on margin- that can and will happen. Amazon isn't even the first here. Some of them, like ANgie's list, are paid for by monthly subscriptions.

Comment Re:Wrong Focus (Score 1) 132

The cornerstone of it is the dusty fission fragment rocket, so I'd start there. Another key aspect is the use of a accelerator-driven subcritical fast reactor rather than a critical slow reactor. Lastly it's a variant of a nuclear lightbulb, albeit (as mentioned) without the primary drawbacks of them (containment and radiation blackening of the chamber blocking the light). This latter aspect is due to the spectrum changes of fused silica (I can't find a paper on short notice that shows the IR spectrum, but you can see that for most types of fused silica / fused quartz, there's little loss of transmission on the red side of the spectrum; this holds true but is even more pronounced in the IR range).

Comment Re:Fukushima and Chernobyl not worse case failures (Score 1) 227

It's certainly not a 'hoax'. Coal contains (to varying degrees) all of these pollutants.

Coal plants do often have filters these days, but always:

http://www.epa.gov/mats/powerp...

the emissions are significant, and not everything gets filtered out.

Also the filtering is expensive and the carbon dioxide that coal emits is becoming a *massive* problem. Although carbon capture has been trialled, it makes coal non competitive with other technologies.

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