German @ Oxley

Non-radioactive water vapour is the significant operating emission from nuclear power plants.[56] Fission produces gases such as iodine-131 or Xenon-133. These primarily remain within the fuel rods, but with some postulated fuel failure, small amounts of the gases can be released in to the reactor coolant. The chemical control systems isolate the radioactive gases which have to be stored on-site for several half-lives until they have decayed to safe levels. Iodine-131 and Xenon-133 have halflives of 8.0 and 5.2 days respectively, and thus have to be stored for a few months to decay to safe levels.

Nuclear generation does not directly produce sulfur dioxide, nitrogen oxides, mercury or other pollutants associated with the combustion of fossil fuels (pollution from fossil fuels is blamed for many deaths each year in the U.S. alone[57]). It also does not directly produce carbon dioxide, which has led some environmentalists to advocate increased reliance on nuclear energy as a means to reduce greenhouse gas emissions (which contribute to global warming).

Like any power source (including renewables like wind and solar energy), the facilities to produce and distribute the electricity require energy to build and subsequently decommission. Mineral ores must be collected and processed to produce nuclear fuel. These processes are either directly powered by diesel and gasoline engines, or draw electricity from the power grid, which may be generated from fossil fuels. Life cycle analyses assess the amount of energy consumed by these processes (given today’s mix of energy resources) and calculate, over the lifetime of a nuclear power plant, the amount of carbon dioxide saved (related to the amount of electricity produced by the plant) vs. the amount of carbon dioxide used (related to construction and fuel acquisition).

Several life cycle analyses show similar emissions per kilowatt-hour from nuclear power and from renewables such as wind power. According to one life cycle study by van Leeuwen and Smith from 2001–2005, carbon dioxide emissions from nuclear power per kilowatt hour could range from 20% to 120% of those for natural gas-fired power stations depending on the availability of high grade ores.[58] The study was critiqued by World Nuclear Association (WNA), rebutted in 2003, then dismissed by the WNA in 2006 based on its own life-cycle-energy calculation (with comparisons).[32]

In 2006, a UK government advisory panel, The Sustainable Development Commission, concluded that if the UK’s existing nuclear capacity were doubled, it would provide an 8% decrease in total UK CO2 emissions by 2035. This can be compared to the country’s goal to reduce greenhouse gas emissions by 60 % by 2050. As of 2006, the UK government was to publish its official findings later in the year.[59][60]