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Re: E-M:/ Future of nuclear power



Dennis Meadows (of Limits to Growth) fame put up a slide at the most recent "Association for the Study of Peak Oil" conference that is a must-see for all concerned. The issue is that, given how capital intensive nuclear power plants are (and capital intensity is a proxy for energy intensity), when do you actually get net energy out of a nuke.  Here is Meadows' slide:

( title is): Years for Nuclear Energy to Give Back Energy

and the text reads:

Assume 4 year construction time.
• Assume 40 year operating life.
• Assume energy payback is 10.
• One plant starts to give net energy in the 9th year.
• A system building one plant/year gives positive net energy
in the 13th year.
• A system building 10% more plants each year gives
positive net energy in the 15th year.
• A system building 20% more plants each year never breaks
even.

It's slide 31 of 37 here:  http://www.aspoitalia.net/images/stories/aspo5presentations/Meadows_ASPO5.pdf

I don't have the data behind this, but it jibes with what I've heard elsewhere (incl. the estimate that it takes more than a decade for a nuke to start paying back more than its embedded energy).

Rane Curl wrote:
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Enviro-Mich message from Rane Curl <ranecurl@engin.umich.edu>
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...snip...
One thing that should be pointed out that emphasizes the gravity of the challenge:  the proposed panacea here (nuclear) is obviously unrealistic--by their numbers, we would have to bring a new 1000 MW nuke on stream /every three days/ for the next 24 years--that's beyond the Nuclear Energy Institute's wildest fantasies---especially since it's thought that it would take 10 years from a standing start to get ONE on line.

Not only that, but the potential supply of fuel for nuclear power appears to be limited. The following is from a discussion of this issue at http://www.fraw.org.uk/mobbsey/papers/oies_article.html

"At the current level of uranium consumption (67,000 tonnes per year) known uranium resources (2.8 million tonnes of uranium) would last 42 years, a fact highlighted by the European Commission in their Energy Green Paper [EC 2001]. The known and estimated resources plus secondary resources (such as the military inventory), a total of around 4.8 million tonnes, would last 72 years. Of course this assumes that nuclear continues to provide just a fraction of the world's energy supply. If capacity were increased six-fold then 72 years would reduce to 12 years. This is because nuclear energy, in terms of global energy supply, must increase by a factor of four to eight to make any significant difference to the use of fossil fuels around the globe. Consequently the expected lifetime of the uranium resource would fall by a similar factor.

"The actual lifetime of the uranium resource will depend upon the technologies adopted as part of any new nuclear capacity. New reactor designs are more thermally efficient (up to 45% to 50% rather than 30% to 35%) which could extend the lifetime of the uranium resource by a factor of 1.7. Introducing a number of fast breeder reactors, to increase the efficiency of uranium consumption, might increase the lifetime of the uranium resource by a factor of 2. Even so, taking these two factors together alongside a six-fold increase in capacity, the lifetime of the known and estimated uranium resource would still be less than 50 years."

--Rane L Curl

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