Nuclear power plants can replace coal, gas fired plants and significantly reduce CO2 emissions.

By Nick Touran, Jan 2007

With the UN Intergovernmental Panel on Climate Change fourth assessment report (Wikipedia) out, it is now a well accepted fact that humans are causing dangerous alterations to the Earth's climate by emissions of greenhouse gasses. The report calls for drastic action to reduce these emissions immediately, even though emissions have steadily increased since the industrial revolution (see the EIA for more emissions details). Additionally, the vast majority of our energy in the US comes from fossil fuel sources (see bar-graph below).

(Source:Annual Energy Review 2005, Report No. DOE/EIA-0384(2005))

The challenge of reducing green-house gasses therefore fights on two fronts: reducing emissions from existing plants and preventing the number of greenhouse gas-emitting plants from increasing. This leaves us with several large-scale challenges:

• Capture almost all greenhouse gasses as they exit fossil-fuel plants

  This option involves retrofitting plants with sequestration technologies that can trap greenhouse gasses as they are emitted from burning fossil fuels. The trapped CO2 is then stored geologically, where it will stay for at least 1000 years according to some studies (more info at Wikipedia). If a commercial use for CO2 could be found which did not involve the eventual release of the CO2, this option would be very attractive. However, it seems that sequestration only solves one of the many problems with fossil fuels. It does not treat the fact that fossil fuels may become difficult and expensive to extract in less than one hundred years, nor does it help with the US dependence on foreign entities. This option should happen on existing plants, but it is not a long-term solution.

• Build power plants that do not emit greenhouse gasses

  This is where nuclear plants really shine. Splitting atoms to make electricity releases no CO2. The gas you see coming out of the cooling towers is water vapor from a nearby river - a product of the thermodynamic cycle needed to run steam turbines. Some CO2 is generated in the overall workings of a nuclear plant, but the amount is trivial compared to fossil fuel plants (see table). Nuclear power plants are capable of generating very much electric power and can directly replace fossil-fuel plants. The spent nuclear fuel is mostly solid and can be disposed of properly, or recycled, without affecting the environment. Nuclear plants can also operate hot enough to separate water into hydrogen and oxygen, and in turn the hydrogen can eventually be used in fuel cells to power vehicles, reducing greenhouse gasses on another level unreachable by any other power source. This option also includes renewable energy, such as hydroelectric, solar, and wind power. These technologies should absolutely be deployed on a large scale, but they will not be able to replace fossil-fuel plants alone, especially in the eastern states. Ideally, fusion nuclear power would be developed, using water for fuel and producing helium as waste.

Emissions Produced by 1 kWh of Electricity Based on Life-Cycle Analysis

(Source: Hydropower-Internalised Costs and Externalised Benefits; Frans H. Koch; International Energy Agency (IEA)-Implementing Agreement for Hydropower Technologies and Programmes; Ottawa, Canada, 2000)