Nuclear Power

June 2008

Nuclear power seems, for all its flaws, to be the best bet for our future energy needs.

Even so, present day nuclear fission technology is at best “a stopgap”, according to MacKay. His numbers suggest that the present method of using uranium would allow the entire human race to live like power-hog Americans in terms of power use for about a third of a year — assuming that only the uranium reserves now confirmed exist. …

At present, there being no scarcity of uranium, it is typically dug from the ground and run through simple power stations just once before being classed as waste. Nobody explores for more uranium, and nobody has done so since the 1980s, because supplies are ample to meet current demand. There’s probably a lot more to be found, especially if the price of ore rose a lot. (Which wouldn’t affect the price of the energy significantly, remember.)

Furthermore, the use of fast-breeder reactors would get sixty times as much juice from a given amount of uranium, according to MacKay. Then, most get-at-able uranium is actually in the oceans, not in the ground — and the scale of the effort needed to mine the oceans for uranium, while noticeable in the same way as the nuclear stations themselves, is much less than mining the sea for wind and tide power.

Then, too, there’s thorium — probably a lot more abundant than uranium, and likewise full of juice.

Even MacKay admits that fast breeders and oceanic uranium together would power the entire human race at hoggish American levels for well over a thousand years, or at current European consumption for several millenia. He also says that known thorium reserves, used with current tech, would run the whole race at rich-westerner levels for several decades.

Heavyweight physics prof weighs into climate/energy scrap

A traditional pressurized water reactor can only fission about 3-5% of the Uranium in it’s fuel before it has to be removed an reprocessed. About 270,000 metric tons of radioactive waste are scattered around the world, predominantly stored in pools or casks right next to the power plants thanks to this inefficiency. If we use the extra neutrons in our fast neutron reactor to burn off the radioactive waste, we can boost this efficiency to above 90%. With some relatively simple fuel-reprocessing on site, we can boost this to 99%.

Nuclear Power: What's Next

We could chemically break down the fuel, purify for Uranium and create new fuel from the old. Great! We’ve now reduced the freakishly radioactive waste we cannot use to a much smaller mass and recycled the fuel. Neat. We stopped doing this in the 1970’s. Why? While the leftover atoms are useless for commercial power plants, they would make great starting material for a dirty bomb. Ouch.

Nuclear Power: Nuclear Waste

Aeonsim commented:

Yep certainly looks that way and if you look at some of the more advanced concept reactors (wikipedia: nuclear reactors) you'll see some designs that would be a lot safer than the previous generation of reactors including some rather advanced subcritical reactors and such like. Thorium also looks like a much safer and more abundant fuel, such reactors would be a good compromise solution until Fusion reactors get sorted.