$1.50 gas with no carbon emissions?

Clearly we just need to build a giant slingshot on Mount Everest and fling nuclear waste into space.

Correct me if I read wrong, but was someone seriously suggesting in this thread that water vapor emissions can cause anthropogenic climate change?

Increased water vapor from manmade sources (power plants, reservoirs, etc.) does affect weather and the climate. Generally not significant enough to turn say a city living on what is practically a desert (city of Pueblo Colorado) into a rainforest but it does. (Pueblo Reservoir occasionally strengthens monsoon storms that pass over it on the way to Pueblo proper. It also does the reverse bleeding energy from them.)

I mean, certainly, if you're putting more vapor into the air that's going to affect things. But the reason why water vapor is the leading contributor to greenhouse gases isn't due to mankind's activities, it's due to the fact that SHIT BITCHES, PLANET'S COVERED IN SEVENTY PERCENT WATER!

I mean, the amount of greenhouse gases that there are, since most of it is naturally occurring water, only a small (but significant) fraction is actually man-made. What would be more relevant is checking whether or not, vehicle per vehicle, water vapor contributes more to greenhouse gases than, say, whatever crap we're spewing out now. I somehow doubt it.

The latter two links are irrelevant to the discussion, I had already talked about spaceworthy nuclear propulsion techniques. The discussion was on atmospheric nuclear rockets. And, it appears I was wrong (about their existence, not the way he described them being used).

x6 Err, what? Current shuttle programs do not use nuclear rockets. Hell, those were discontinued apparently.

The hell are you talking about? I never said they are nuclear rockets. They use hydrogen and oxygen reactants that are made by electrolizing water. The only difference between what was suggested before and now, is that the electrolizer isn't powered with nuclear power, it's coal powered IIRC.

The issue with nuclear power and rockets isn't so much the energy density of the fuel, it's the amount you can get out in a given period of time (without disintegrating the rocket). With nuclear fuel, the margin between "boils water" and "explodes in a radioactive fireball" is far too narrow to make it an effective propulsion source.

Using nuclear power to produce rocket fuel is fine as far as it goes, but you can use nuclear power to produce anything that could be done by generated electricity. Electricity is fungible on the input side.

Yeah. Or we could go with an Orion Drive. Those fucking space elephants will never see it coming!

Nuclear propulsion is an interesting concept. They've made prototypes, although some aren't very practical to build and use now, and people start getting pretty nervous when you mention "nuclear-powered" and "rockets" in the same sentence. Environmentalists have a fit with just having an RTG in a satellite, even.

More here. That site is totally awesome, by the way.

The problem with rockets is that with current fuel-oxidizer systems, it costs a whole lot of money to send even one pound into orbit. IF you want to send it higher up - like, into an escape vector away from Earth - you'll need even more fuel. It's not just a simple matter of sticking another stage onto the thing to do so, either, you need to account for the fact that the first stage has to lift everything, then detach, then the second stage has to lift the remainder into a low orbit, and the third stage is what's used to shove your payload (nuclear waste in our case) into deep space.

With current technology, it costs about ten thousand dollars to send a pound into orbit. That's fuel, the launch vehicle itself, and probably a bunch of other stuff I don't realize.

Consider the fact that the world makes twelve thousand tons of high-level nuclear waste a year, and I'd think it would be obvious that rockets are not cost-effective means to get rid of it. But it's not just cost you'd have to consider - no single launch vehicle could hold all that waste, which is increasing every year. With more launches, the certainty of a launch vehicle mishap approaches certainty, and I'd not want to be the guy in charge of that program when the crap hits the fan.

No; burying it or transmuting it is the better and safer solution. We could do be doing a better job of managing it, yes, but shooting into orbit isn't a viable consideration in my eyes.

Anyway. I'm all for hydrogen ICE's and all-electric cars. I probably won't even consider buying an all-electric one until/unless I have a house. Running an extension from my second-floor apartment would be a chore, and Hawaii doesn't have a very robust power grid to deal with them now.

Isn't some of the waste we make reusable though?

Yes it is, if you make the right reactors. Here's what I was talking about earlier.

Fast spectrum reactors, also known as 'Generation IV', are able to use 99.5 per cent of the energy in uranium. There is enough energy in already-mined uranium and stored plutonium from existing stockpiles to supply all the world's power needs for over a century before we even need to mine any more uranium. Once we do start mining again, there is enough energy in proven uranium deposits to supply the entire world for at least 50,000 years. Fast reactors can be used to burn all existing reserves of plutonium and the waste stream of the past and present generation of thermal reactors.

The safety features of Gen IV designs, due for instance to the metal alloy fuel used, is superior even to the ESBWR. The nuclear fuel used by fast reactors is fiendishly radioactive and contaminated with various heavy elements (which are all eventually burned up in the power generation process!), making it impossible to divert to a nuclear weapons programme without an expensive, heavily shielded off-site reprocessing facility which would be easily detected by inspectors.

Yet in reality the only nuclear waste material that will ever leave an Integrated Fast Reactor complex (a systems design for power stations which includes on-site reprocessing) are fission products, which decay to background levels of radiation with a few hundred years (not hundreds of millennia), and can be readily stored because they produce so little heat compared to 'conventional' nuclear waste.

More.

Basically, a better reactor that has less waste being produced (and even runs off of existing wasted fuel?). I'm in favor of it.

edited 29th Jan '11 4:41:19 PM by pvtnum11

Stuffing it under a mountain and recycling what you can is more cost effective. I just like the idea of building giant rockets to fling things into space. Since the space program is underfunded.

Which is why I suggested a railgun. OK, streams of plasma 100km long might cause problems, but it'd be cheaper than rockets, nuclear-or-otherwise.

But yeah, Gen IV fission is the way to go. (At least, until someone gets fusion working)

OK, streams of plasma 100km long might cause problems awesomeness,

fix'd

Railguns have terrible power efficiency, per what I've read.

But you don't have to haul the mass of the rockets up. I'm still favoring the giant potato gun just a smidgen more.

A space elevator + orbital launching is probably the best long term solution. At least until we get 100% mass to energy conversion worked out.

edited 30th Jan '11 10:58:24 AM by Fighteer

Space Elevator is the solution to everything.

Between the space elevators and the plasma trails, this became the best thread on OTCthe fora in 5 posts.

I congratulate you, gentlemen.

100% mass to energy conversion is easy: smash antimatter into it.

edited 30th Jan '11 11:43:56 AM by Yej

A high g-force launcher is what we need now.

Can you imagine listening to elevator music for a couple of hours though? That's a long ride up.