Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
Display:
Me too.  This is bogus.  Japan did a study and found that carbon emissions from nuclear power there were even lower than those from wind power.

You can find an interesting analysis of the dubious claims Friends of the Earth are making at the following site:

http://www.world-nuclear.org/co2&nfc.htm

The paper gives a history of where this claim originated and its basis. Frankly I found the paper somewhat confusing. The argument seems to be this -- it takes energy to produce uranium fuel, primarily required for enrichment. If one assumes coal is used to produce the electricity powering the diffusion plant, a German analysis showed (Table 1) that 38,300 tons of carbon would be emitted annually for a 1300 MWe LWR.

Using 2000 data from DOE (available at their eia.doe.gov website), you can calculate that annual carbon emissions based on 1999 numbers for an equivalent sized coal plant would be 8.6 million metric tons per year. Thus a nuclear fuel cycle under these assumptions would produce .5% of the carbon emissions per year that would be produced from an equivalent coal plant.

For another well-reasoned refutation of that FOE claim from a UN organization, see this pdf:

http://www.iaea.org/OurWork/ST/NE/Pess/assets/03-01708_Rognerspeech.pdf

Now the fun stuff -- from the paper at the above site, the Friends of the Earth evidently argued that low grade uranium will required once we "run out of" high grade uranium ore meaning more energy to produce enriched uranium fuel, thus releasing even more carbon annually. The problem I have with this -- I can't find the FOE paper --  but I can't conceive of a situation where even low grade ores would change this ratio substantially. Even if the grade were 1% of the quality of high grade ore, the annual CO2 emissions would increase the contribution by mining by 100 fold -- from 9100 tons per year (in Table 1) to 910,000 per year -- raising the total from .5% to maybe 1-2%. I don't see how you get from here to there. Moreover, it doesn't make sense that you ever could -- if you did, it would mean you need more coal electricity to produce the uranium than you would get from the uranium itself -- just doesn't make any sense.

The other arguments the Uranium Institute makes in rebuttal are straight-forward -- the electricity to process uranium does not have to come from coal; there are ways to enrich uranium more efficiently, especially using centrifuges; and the requirement to enrich uranium is substantially mitigated if fuel is reprocessed. Moreover, as I argued elsewhere, the availability of high grade ore will expand with more exploration as nuclear power demands more fuel.

by Plan9 on Wed Oct 19th, 2005 at 11:04:15 AM EST
[ Parent ]
...multiplying .5% 100-fold give you 1-2%? It gives me 50%. (Actually, more like 33%, but that's another story)

the annual CO2 emissions would increase the contribution by mining by 100 fold -- from 9100 tons per year (in Table 1) to 910,000 per year -- raising the total from .5% to maybe 1-2%.


A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Carrie (migeru at eurotrib dot com) on Wed Oct 19th, 2005 at 11:17:20 AM EST
[ Parent ]
Thanks for calling this to my attention.  I shouldn't post when in a hurry.

I was referring to the impact it would have on the total contribution from the table. But I agree I got a decimal displaced. Here's the table:
www.world-nuclear.org/co2&nfctab1.htm

Mining and Milling -- 9100 tons
Conversion --           1400 tons
Enrichment --        27200 tons
Fabrication --            600 tons

Total  -- 38300 tons of CO3 per a 1300 Mwe nuclear plant. The comparable number from a 1300 Mwe coal plant is 8,600,000 tons. The ratio is .4%.

If the uranium is low grade -- reduced in grade by a factor of one hundred -- one assumes that means the contribution from mining and milling is increased to 910,000 tons. That makes the total 939,200 tons. The ratio is now 939200/8600000 or 11%. I missed a decimal someplace in my earlier communication, but the point is still valid. Even if you use low grade ore, and you further assume all the energy would come from coal- fired electic plants, these numbers still say the carbon emissions are only 11% of what they would have been had the electricty come from coal. The reason it does not go up in proportion to the grade of the uranium is the contribution from the other steps, especially enrichment, remain unchanged.

by Plan9 on Thu Oct 20th, 2005 at 08:34:00 AM EST
[ Parent ]

Display:

Occasional Series