Talk:Nuclear thermal rocket

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How about the other designs? Gaseous core designs have neen proposed, I think. I just don't have enought information to include in a decent article section... but this info is lacking.

There's a stubby article on it at Gaseous fission reactor. I'll put a link to it into this article. Bryan 01:01, 3 Jun 2004 (UTC)


Can someone please explain to me (or preferably to everyone by adding to the article) just what the heck is happening in this [1] picture? The caption in the article and the one on the nasa site are really unhelpful. Am I truly looking at a runaway criticality/excursion and explosion of a nuclear reactor core here or what?! If so this must've released a massive amount of radionuclides into the atmosphere and surrounding landside. If so, why is there apparently no other information on this event...yeild of excursion, fallout, cleanup(if any??)?--Deglr6328 05:45, 13 Oct 2004 (UTC)

I'm not an expert but I feel quite confident in saying that's not a nuclear explosion, nuclear reactors don't go critical in the way bombs do. My guess would be that they simply cranked up the power output until the reactor melted or burst from the pressure of the heated propellent, after which the reactor would have stopped working. Bryan 06:02, 13 Oct 2004 (UTC)

Contents

[edit] Pu releases

"Three to five tons of plutonium (about 320,000 curies) were released into the atmosphere by weapons testing from the end of WWII (1945) until the Partial Test Ban Treaty was signed in 1963. No deaths have been detected from this, even though anti–nuclear organizations state that one gram (1/28 of an ounce) of plutonium is enough to give everyone on Earth cancer." What is this non sequitur? 3 to 5 tons of Pu, seems it should say something like 300,000 - 500,000 curies, or what ever it should be. The point is if the mass is a range, so should be the amount of radioactivity. How do we know this figure? Then, is it just Pu? Some of those are U explosions. And every nuclear explosions produces some of EVERY nuclide. Then if there were/are some excess deaths/cancers from this added radioactivity, how could it be reliably associated with the addition to the background? But just because it is hard to pin down doesn't mean it isn't happenning. An then the sentence continues with a claim that someone said, as if that were the only thing people have to say. So how much Pu WOULD it take to give everyone cancer? Properly applied, not much. Small breathed in particles. But that's not the point. That's like asking how much water would it take to drown everyone on earth. About a bucket, if we all take turns. Ie sounds editorial to me. As far as cancer goes, those atmospheric tests cause uneven distribution. People nearby got a lot more than further away. .. So just averaging out 5 tons over the whole atmosphere is very misleading. Like I said in edit now commented out, Cancer accounts for half the deaths of advanced societies. Seems to be problem. Comments? 67.118.117.2 03:32, 3 Nov 2004 (UTC)

"Between 1963 and 1980 the U.S. exploded 316 nuclear devices underground. The radioactivity from these is already equivalent to the nuclear waste from many nuclear reactors." Request for clarification. Does this mean the r.a. released into the atmosphere is == to r.a. released into atmosphere from nuclear waste ? Or does it mean r.a. waste , or what? 67.118.117.2 03:38, 3 Nov 2004 (UTC)

These passages have been added twice now, and I have twice removed them. For one, these engines do not use Pu, so any comment on Pu release is obviously of limited use. Furthermore, the editor made no attempt to compare these releases with the amount of uranium in these engines (which is likely difficult to find anyway) so it really doesn't help anything. Maury 16:29, 23 May 2006 (UTC)
They have been added, and removed, again. The IP of the anon user in question ends up at Lockheed Martin, which seems ironic. Maury 01:06, 29 June 2006 (UTC)

[edit] Thrust-to-weight

The statement that a solid-core reactor cannot have a T/W >1 only applies to NERVA. The designers weren't trying hard for high thrust because they didn't expect to use it as a booster. DUMBO (mentioned lower on the page!) had a higher thrust. A particle-bed reactor, as designed in the Timberwind program, wouldn't have only had a T/W slightly greater than 1. I don't know if the design was realistic, but Timberwind was supposed to have had a T/W of 30, enabling it to propel a launch vehicle. SpaceCaptain 02:44, 30 September 2005 (UTC)

[edit] LOX as propellant

Just a curious observation, nuclear thermal has a lot going for it, but no one ever considered using lunar LOX as a propellant mass instead of H2. Other than the annoying reactive properties of oxygen, there would be little difference as a propellant. But, oxygen could be readily extracted from regolith on the moon, creating a limitless supply of propellant mass to reach the outer solar system. Launch masses for trips to other planets could be cut in half.

Actually, it has been considered. [2] LOX offers a much lower exhaust velocity than LH2, but higher density and greater stability in storage (it doesn't boil off). And, of course, it's available on the Moon. SpaceCaptain 18:26, 22 December 2005 (UTC)

[edit] Calculations in § Nuclear vs Chemical

In th following step :

Finally, one must consider the design of the stage as a whole. The S-IVB carried just over 300,000 litres of fuel, 229,000 litres of liquid hydrogen (17300 Kg), and 72,700 litres of liquid oxygen (86 600 Kg). The S-IVB uses a common bulkhead between the tanks, so removing it to produce a single larger tank would increase the total load only slightly, for argument's sake, perhaps 2,000 litres. Assuming this for the moment, this means the new hydrogen-only nuclear stage would carry about 231,000 litres in total (231 m³), or about 16,500 kg (36,350 lb). At 1,725 litres per second, this is a burn time of only 135 seconds, compared to about 500 in the original S-IBV (although some of this is at a lower power setting).

Why is the new capacity 229,000+2,000 ? It should be as said a single larger tank of 303,700 l

With this volume, burn time is about 170 s and delta-V 6600 m/s. These values don't compromise the subsequent argumentations. Duckysmokton 14:38, 30 November 2006 (UTC)

I think I'm missing something, 229000 + 2000 = 231000? Maury 13:12, 6 December 2006 (UTC)
Ohh, duh. Please, feel free to fix my error! Maury 13:18, 6 December 2006 (UTC)