I recently found a very interesting and useful feature on a somewhat-anti-nuclear website:

Nuclear Fuel Energy Balance Calculator

This nifty little site lets you type in the quantity of interest to you (such as the amount of electricity you want to generate) and then it will quantify most of the other aspects of the fuel cycle. I want to try to use that calculator to answer some persistent questions I’ve had.

The mining and processing of uranium for nuclear reactors generates more CO2 than is saved by the reactor’s operation vs. a coal plant.

This is one of those silly assertions that seems to ludicrous at face value, yet I see it repeated over and over again by anti-nuke posters on different websites. Perhaps they want it to be true so badly that they never investigate it. I’m sure the idea that nuclear power is NOT emitting so much CO2, and they are opposed to it, grates on them to the point where when they hear such a palpable absurdity, they believe it and repeat it.

So it was a good question to put to the WISE Uranium Calculator. I felt pretty safe in assuming that these guys would NOT be giving uranium the benefit of the doubt! So I punched in 1 GWae (1000 megawatts of electricity, per are, or year) and out popped the results:

For their default values of all other quantities, they projected roughly 300,000 tonnes of CO2 would be emitted by the mining, milling, conversion, enrichment, and fuel fabrication of the uranium necessary to produce this level of electricity. 300,000 tonnes sounds like a lot until you compare it to the amount of CO2 that would be emitted by a coal plant trying to make 1000 MW*yr worth of electricity: 8.2 million tonnes of CO2, or 27 times more CO2 than the nuclear option. Examined another way, the nuclear plant only has to run 14 days before it has generated enough electricity to “pay” for its fuel for the year.

It is also worth considering that most of the energy input for the uranium preparation was in enrichment of the uranium, and they assumed that the electrical energy for enrichment came from fossil-fueled plants. If this electrical energy came from nuclear plants, the CO2 emissions would be even less.

So it is clear that the assertion that conventional nuclear plants will generate as much CO2 from their fuel cycle as a coal plant is patently absurd.