Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
...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:

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 ]


Occasional Series