nuclear piston engine

[joiz]

okay, so you make this giant thing underground with pistons that resemble the orion nuclear ships. drop out a nuke, blow it up, moves the first piston, repeat many times, attach a shaft at the end to a huge generator. great use of nuclear weapons. you could also make a smaller one that runs on davy crocket or suitcase nukes, or even to make an easy fusion power plant! advantages are: easy fusion plant, no waste (it gets vaporised) you can get rid of old nukes that would otherwise just sit around and be dangers to humanity. etc..

 

[Andy44]

Creates fall-out, though. Conventional nuclear power is much easier and safer.

Interesting note, though, if Orion had gone ahead there were plans to build an underground test facility similar to what you describe, in which nuclear propulsion charges would be tested agianst various pusher plate designs.

 

[joiz]

well, what if we made it on the moon? i guess if we bothered to put the nukes into space might as well use em for an orion.

 

[Eagle]

well, what if we made it on the moon? i guess if we bothered to put the nukes into space might as well use em for an orion.

I'd say enough people bothered to keep the nukes out of space to make that rather difficult.

 

[TMac3000]

At first blush the Orion spacecraft sounds like a nutty idea (Hey, let's sit on some nuclear warheads and detonate them!), but the big pusher plate (it would have to be one metric hell of a big pusher plate) also acts as a shield, so the concept is sound for interplanetary flight (point one c is way too slow for the stars).

Fallout is not a problem, as it will be out in interplanetary space if you use old fashioned chemical rockets to get started. Radiation seeping through even significant shielding is the only real drawback. Anyone ever read Farthest Star by Frederik Pohl and Jack Williamson?

 

[Andy44]

Fallout is indeed a problem for what the OP wrote.

 

[Pquardzvaark]

Isn't the biggest issue the EMP though? I remember reading that fallout can be reduced based off the launch site design, or begin with a conventional launch. Frying all your satellites sounds worse.

Anyway, I don't wanna digress too much about Orion, though I love the idea. On topic, there was a proposal called PACER to use underground nuclear explosions to heat up salt which would be used to generate electricity. Anyway, how much does it cost to build a nuclear bomb for power generation? Granted with economies of scale it should go down, but I can't imagine it'd be a cheap venture unless you want to use otherwise decommissioned weapons.

 

[sputnik]

Oh, that's Project Pacer: http://en.wikipedia.org/wiki/PACER_(fusion)

 

[Andy44]

Forgot a parentheses, sputnik! http://en.wikipedia.org/wiki/PACER_(fusion))

Sounds like a pretty tough way to use fusion for power. To have to build bombs to produce heat is problematic to say the least, especially since you need lots of dirty fission reactions to make material for the bombs. The ideal fusion reaction would use no fission or uranium/plutonium, just hydrogen.

Somewhere in Dyson's son's book about Project Orion one of the bomb designers said they thought they might be able to build a fusion bomb that used no fission trigger, and would thus be much cleaner, but they were afraid that it would make thermonuclear explosives too easy to build and they never got the go ahead to pursue it anyway.

 

[RisingFury]

Have you ever considered *why* we build things the way we do? Or how it works in the first place? Continually making nuclear weapons just to blow them up for power would be economically ridiculous, not to mention making a piston power plant.

Any kind of piston engine is inherently inefficient because you continuously need to accelerate and decelerate the mass of the pistons, wasting a huge load of energy there. A rotary engine is far more efficient with that, which is why power plants have rotary turbines.

Not to mention that to produce power, you'd need to continuously operate your engine, which would mean that you would use up your stockpile of world's nuclear weapons in a few seconds (even if they were toned down to not destroy your engine in the first place). The power in your home is AC at 50Hz... that means the generator has to rotate 50 times per second as well.... which means you blow up 50 nuclear weapons per second.

 

[tblaxland]

Not to mention that to produce power, you'd need to continuously operate your engine, which would mean that you would use up your stockpile of world's nuclear weapons in a few seconds (even if they were toned down to not destroy your engine in the first place). The power in your home is AC at 50Hz... that means the generator has to rotate 50 times per second as well.... which means you blow up 50 nuclear weapons per second.

If you read the article you would notice that the power is not extracted by using a reciprocating nuclear piston. The nuclear bomb heats a salt slag (or similar) and the heat is extracted from it via a heat exchanger to drive steam turbines. The rate of detonation is therefore determined by the rate at which you extract heat from the slag, so it is demand based and thereby more effective. Still not economically viable, IMHO, but an important distinction nonetheless.

 

[RisingFury]

If you read the article you would notice that the power is not extracted by using a reciprocating nuclear piston. The nuclear bomb heats a salt slag (or similar) and the heat is extracted from it via a heat exchanger to drive steam turbines. The rate of detonation is therefore determined by the rate at which you extract heat from the slag, so it is demand based and thereby more effective. Still not economically viable, IMHO, but an important distinction nonetheless.

Yes, that's what the article says (which I find incredibly ridiculous too). But maybe you should read the first post to understand my reply.

 

[sputnik]

Yes, I think Project Pacer's main value is as a thought experiment. You can extract energy from any heat engine, and nukes are a BIG heat engine....

I don't see how it could possibly be cost-effective either, even assuming you get the nukes for "free" (you're trying to dispose of them, or something).

---------- Post added at 07:55 AM ---------- Previous post was at 05:53 AM ----------

Actually, now that I think on it, I could think of a fine science-fictiony rationale for Project Pacer-style power plants: powering planetary defenses.
I'm thinking, in particular, of Traveller-style meson guns, which are already buried deep in the planet. To run them, you need gobs of power on standby, but don't want to rely on plants on the surface, or power links which could be interrupted, and you don't want to spend a lot on maintenance of your own, dedicated, power plant.
Pacer would work there: gobs of power for durations on the order of hours or days or perhaps weeks, relatively low maintenance when you're not using it, you can put it right next to the two-mile-deep cavity you've already dug for the meson gun....

(You could try adding rods running to the surface to make it a bomb-pumped X-ray laser as well, but given that this compromises your stealth and doesn't fire very often, I doubt that'd be a very good idea).

For added chrome, you could say that the opposing fleet has neutrino detectors to find your fusion plants, but bomb-pumped plants fire too briefly to triangulate, making the whole thing stealthy! Sure, anyone with some seismographs can figure out where the plants are, but a siesmograph need to be on the surface, and the idea is to keep the bad guys off the surface....

Well, just a notion.

 

[RisingFury]

Yes yes yes... in sci-fi all is good, even hyperspace and faster then light travel.

 

[Andy44]

Well, if we're talking sci fi, maybe HG Wells' Martians used nukes as "gunpowder" to fire their projectiles towards Earth. Kind of a one-shot Orion drive.

 

[Hielor]

Not to mention that to produce power, you'd need to continuously operate your engine, which would mean that you would use up your stockpile of world's nuclear weapons in a few seconds (even if they were toned down to not destroy your engine in the first place). The power in your home is AC at 50Hz... that means the generator has to rotate 50 times per second as well.... which means you blow up 50 nuclear weapons per second.

I think you vastly underestimate the number of nukes in the world's stockpile. Even at 50 Hz you'd last far more than "a few seconds."

 

[Ghostrider]

well, what if we made it on the moon?

Nukes on the Moon. Hurm, sounds familiar...

 

[Sky Captain]

What you described is called Atomic Ignition Engine. It`s used to power all types of HAB vehicles.

http://www.stardestroyer.net/mrwong/wiki/index.php/HAB#Atomic_Ignition_Engine

Remember, there are no such thing as too much power

 

[joiz]

Have you ever considered *why* we build things the way we do? Or how it works in the first place? Continually making nuclear weapons just to blow them up for power would be economically ridiculous, not to mention making a piston power plant.

Any kind of piston engine is inherently inefficient because you continuously need to accelerate and decelerate the mass of the pistons, wasting a huge load of energy there. A rotary engine is far more efficient with that, which is why power plants have rotary turbines.

Not to mention that to produce power, you'd need to continuously operate your engine, which would mean that you would use up your stockpile of world's nuclear weapons in a few seconds (even if they were toned down to not destroy your engine in the first place). The power in your home is AC at 50Hz... that means the generator has to rotate 50 times per second as well.... which means you blow up 50 nuclear weapons per second.

allright, allright, its just a silly little fantasy ok? and concerning this rotation of 50 per second, there this marvelous contracption, invented long before nuclear power even existed. its called a gearbox.

---------- Post added at 08:46 PM ---------- Previous post was at 08:44 PM ----------

Nukes on the Moon. Hurm, sounds familiar...
YouTube - Space 1999 Intro

I never understood why they put the music that seems more fitting for "james bond in the hawaii menace" then a space TV show.