Spotlight: What makes nuclear energy low-carbon?

Spotlight: What makes nuclear energy low-carbon?

from AREVA North America: Next Energy Blog by AREVA North America Blog

As politicians, the media, and everyday Americans continue the debate regarding our future energy sources, we believe that claims should be backed by clear science, reason and logic. One often disputed argument is how one can consider nuclear energy a low carbon source. Building nuclear power plants can play a major role in reducing carbon emissions while helping to meet our growing energy demands. It is fair to ask, where do these figures come from?
First, nuclear power plants do not emit pollutants or greenhouse gases when they operate. This means that the 104 U.S. plants generating 20 percent of electricity throughout the U.S. do so without producing greenhouse gas emissions. The same is true of renewable energy sources, such as solar, wind, and hydropower.
However, as with any power plant, it is not just the emissions during operation that should be taken into account. The construction and related activities from start to finish of a plant all create associated outputs, called life-cycle emissions. It is similar to buying an electric car to cut back on your own carbon footprint. It is true that the electric car produces significantly fewer emissions than the average gasoline-powered engine. However the electric car must be built, shipped, maintained, and ultimately taken to the junk yard —all of this counts. (One might also consider what is the energy source producing the electricity for the car—coal, gas, nuclear, renewables—and their related emissions).
Looking at the start of operations until the finish, numerous studies demonstrate that nuclear energy’s life-cycle emissions are comparable to renewable forms of generation, such as wind and hydropower, and still far less than those of coal or natural gas plants. Although nuclear plants do not emit greenhouse gases when generating electricity, certain processes used to build and fuel the plants do. This is true for all energy facilities. Nuclear energy life-cycle emissions include emissions associated with construction of the plant, mining and managing the fuel, routine operations, disposal of used fuel and other byproducts, and decommissioning.
The International Energy Agency (IEA) has found that nuclear power’s life-cycle emissions range from 2 to 59 gram-equivalents of carbon dioxide per kilowatt-hour. Comparatively, the life-cycle of wind (7 to 124 grams of carbon dioxide-equivalents) and solar photovoltaic (13 to 731 grams of carbon dioxide-equivalents) produce more, while only hydropower’s range ranked lower, at 2 to 48 grams according to the IEA. And just for comparison, life-cycle emissions from natural gas-fired plants ranged from 389 to 511 grams of carbon dioxide-equivalents per kilowatt-hour.
So what does that all mean? To make a real comparison, nuclear-generated electricity avoids almost 650 million metric tons of carbon dioxide per year in the U.S. This is nearly as much carbon dioxide as is released from all U.S. passenger cars (but not necessarily the type of electric cars mentioned previously). If nuclear energy did not produce 20% of U.S. electricity and avoid hundreds of millions of tons of emissions, then required reductions in the U.S. would increase by more than 50 percent to achieve targets under the Kyoto Protocol.
And since one reactor can provide enough power for more than one million homes on a reliable basis, you really can do more with less.