Power-full questions

[bluegargantua]

Hey,

Two questions for the energy production crowd:

1.) How long do nuclear fuel rods last? This is kind of a vague question I know, but what I'm getting at is this: more and more people are boosting nuclear energy as an energy solution. Fine. But Uranium isn't exactly the most common element in the world. If we switched over to a heavy nuclear base, then we're going to start gobbling up uranium and it's just as susceptible to running out as oil is (if not more so). My impression, is that nuclear fuel lasts for a good long while before it's too depleted to be useful, but I'm hazy on it. So what's a good estimate for how long a fuel rod will last in a modern plant? If you have data on how long nuclear fuel will last in more exotic new-fangled reactor types (like pebble-bed) feel free to chime in, but I'm mostly interested in how it works now.

2.) In all this talk about alternative energy, I've always thought that geothermal has gotten short shrift. The planet is hot and it's going to stay that way for awhile and it seems more reliable than wind or solar. It seems like an easy no-brainer to push hard on geothermal. So I'm curious as to what the hold up is. Is it mostly politics? Is it just really hard figuring out how to drill deeply enough to set one up? Are there other reasons?

later
Tom

Comments

[insegnante.livejournal.com]

here's kind of your answer

[insegnante.livejournal.com]

You might also be interested to know that we don't have to use just Uranium.
Nuclear Fuel

[trom.livejournal.com]

Well we looked at geothermal for our house (appx 1300sq ft) and all the estimates were in the 30-40K range and that would get the air to 55^F which is huge, but we'd still need some sort of additional mini-furnace on top of that. If/when it becomes more cost effective (most of the cost is drilling and installation of the ground loop), we'll reinvestigate it.

[bluegargantua]

This is more on an industrial-scale kinda deal where we hope to power neighborhoods and towns rather than individual homes. But an interesting data point.

later
Tom

[z-gryphon.livejournal.com]

To get enough heat to make enough steam to generate electricity on an industrial scale, you have to go unfeasibly deep in most places. There are exceptions - Iceland, for instance - but in, say, upstate New York it's not really workable right now.

[bluegargantua]

Yeah, that's what I thought, it's more a drilling/materials issue.

huh
Tom

[pfloyd.livejournal.com]

One of my favorite methods for alternative energy is tidal power.
The oceans have some pretty strong tides, and this former oil magnate has gone "green" and become involved in this project down in Oz.
Here's the skinny: you have a float that rides either on the surface or at some point in the water where the tidal forces and currents are rather strong. The vertical motion of the float drives a pump that sends pressurized water to a point on the shore, where it's diverted to either a water-driven power station or a desalinization plant, and then returned to the ocean. (I keep thinking, why not both?)
I believe his current project generates enough power for a small town on the northwestern Oz coastline, as well as providing fresh water.

[bluegargantua]

I believe I also read about an idea where you sent pipes into deep-ocean water. You pump in this really cold water and use the heat differential in a giant thermocouple.

later
Tom

[z-gryphon.livejournal.com]

This idea has been tossed around up in the Maritime Provinces for years - the Bay of Fundy has colossal tides, some of the biggest in the world, and it's occurred to more than one person over the years that you could get some serious work out of that if you built the right equipment. There's one generating station up there now, but as you might expect, the environmental lobby protests it regularly because it's a dam and Dams Are Bad. (Someone's working on another system that just sort of sits in the water and uses the flow as the tide goes in and out, but there are questions about whether that'll ever be efficient enough to bother with. Be pretty cool if it worked, but I'm sure the greens will find something about it to picket if it does. The turbines could suck in a fish or something.)