How many nuclear power plants would we need to get us to 100%

[Altair_IV]

22. Not the UCS

kristopher,

In my many years of serving as a Professor of Physics at MIT in Cambridge; I frequently had my opportunities to debate representatives from the Union of Concerned Scientists at many public forums having to do with nuclear power. Despite their name; they most certainly are not scientists. I've know elementary school kids that have a better grasp on the science than the representatives from UCS. They are mostly a bunch of economists. The organization was started by a former colleague of mine; Professor Henry Kendall; but he's about the limit to the scientific expertise that UCS has. So I really don't care to visit any of the propaganda at the UCS website. Perhaps you could get some other substantiation besides those clowns at the UCS.

It's actually quite simple. First, do you know what the composition of spent fuel or nuclear waste is? About 96% of "nuclear waste" is Uranium-238. That Uranium-238 is slightly radioactive; but it is no more radioactive than any other bit of Uranium-238 that is still in the ground, and hasn't been mined yet. Uranium-238 is one of the most uniformly distributed elements in the Earth's crust. You have Uranium-238 in the dirt in your back yard; and if we do a careful analysis of the dirt under your fingernails; we will find Uranium-238.

So Uranium-238 is all around us, and doesn't require the special disposal of a Yucca Mountain. The Uranium-238 from spent reactor fuel could just be put back into the same Uranium mine where we got it in the first place.

So just doing that step "solves" 96% of the nuclear waste problem. The other 4% of the waste requires the Yucca Mountain treatment if we use a "once through" cycle.

Besides, the whole "volume" issue is really a red herring courtesy of the idiots at UCS. In a little over a half-century, the nuclear power program in the USA has resulted in about 77,000 metric tonnes of nuclear waste. Sounds like a lot? However, if we were to place all that nuclear waste in a single location; the volume would be about the same as a high school gymnasium. Volume really isn't the issue.

So many of the antinuclear types forget about how much energy we get per unit mass using nuclear power. Pound for pound, or kilogram for kilogram; we get *millions* of times more energy from nuclear reactions than we do from chemical reactions.

A kindred spirit of mine, another Physics Professor; Richard Muller of the University of California - Berkeley made that point very emphatically in his textbook:

http://muller.lbl.gov/teaching/physics10/PffP_textbook_F08/PffP-01-energy-F08.pdf

Page forward to where he calls out that statement in a little paragraph all its own and suggests that it is so important that the reader should memorize it.

Since we get millions of times more energy per unit mass from nuclear than from other sources; that means for a given amount of energy ( which is what we are interested in ), we need burn a million times *less* of nuclear fuel vis-a-vis some other type of fuel.

So volume really isn't the big issue. The big issue for nuclear waste is longevity. That's where the benefits of reprocessing really shines. If you don't reprocess, your waste stream has nuclides like Plutonium-239 with a half-life of 24,100 years. That means your waste has to stay isolated from the environment for a long time, and that is a challenge to ensure.

However, if you reprocess, you take the Plutonium-239 and the other actinides out of the waste stream; and put them back into the incoming fuel stream, and send them back to the reactor to be burned. In addition to being long lived, *all* the actinides can be fissioned.

So if one reprocesses, the waste stream only contains fission products. Fission products have lifetimes that are at most a few decades. You only have this "tens of thousands of years long" nuclear waste problem if you don't reprocess. If you do reprocess, then the longevity of the waste is thousands of times less. That advantage alone is worth all the expense and effort to reprocess / recycle in my book.

Altair_IV