Originally posted by: Wikipedia
Nuclear power is the use of sustained nuclear reactions to do useful work (in the past, this was called Atomic Energy). Currently, Nuclear power is generated by nuclear fission reactions which occur when sufficient amounts of uranium-235 and/or plutonium are confined to a small space, often in the presence of a neutron moderator. The reaction produces heat which is converted to kinetic energy by means of a steam turbine and then a generator for electricity production. Nuclear power currently provides about 17% of the world's electricity and 7% of global energy. An international effort into the use of nuclear fusion for power is ongoing, but not expected to be available in commercially viable form for several decades.
After a period of decline following the 1979 Three Mile Island accident and the 1986 incident at Chernobyl, there is a recently renewed interest in nuclear energy because it could partially address both dwindling oil reserves and global warming with fewer emissions of greenhouse gases than fossil fuel.
The use of nuclear power is controversial because of the problem of storing radioactive waste for indefinite periods, the potential for possibly severe radioactive contamination by accident or sabotage, and the possibility that its use could in some countries lead to the proliferation of nuclear weapons. Proponents, including some national governments, claim that these risks are small and can be lessened with new technology. They claim that France and all of the industrialised economies of Asia see nuclear power as a key economic strategy, that the safety record is already good when compared to other energy forms, and that nuclear power is a sustainable energy source. Many environmental groups claim nuclear power is an uneconomic, unsound and potentially dangerous energy source, especially compared to renewable energy, and dispute whether the costs and risks can be reduced through new technology.
In 2005, there were 441 commercial nuclear generating units throughout the world, with a total capacity of about 368 gigawatts. 111 reactors (36GW) have been shut down.80% of reactors (and of generating capacity) are more than 15 years old.
In 2004 in the United States, there were 104 (69 pressurized water reactors and 35 boiling water reactors) commercial nuclear generating units licensed to operate, producing a total of 97,400 megawatts (electric), which is approximately 20 percent of the nation's total electric energy consumption. The United States is the world's largest supplier of commercial nuclear power. Future development of nuclear power in the U.S. (see the Nuclear Power 2010 Program) was enabled by the Energy Policy Act of 2005. As of 2005, no nuclear plant had been ordered without subsequent cancellation for over twenty years, thus the need for programs to promote new construction. However, on September 22, 2005 it was announced that two sites in the U.S. had been selected to receive new power reactors (exclusive of the new power reactor scheduled for INL) - see Nuclear Power 2010 Program.
In France, as of 2004, 83.4% of all electric power was generated by 58 nuclear reactors, the highest share in the world.
Argentina, Brazil, Canada, China, Finland, India, Iran, North Korea, Russia, Pakistan, Japan, South Korea, Taiwan, Ukraine, and the U.S. are currently planning or building new nuclear reactors or reopening old ones. Bulgaria, Czech Republic, Egypt, France, Indonesia, Israel, Romania, Slovakia, South Africa, Turkey, and Vietnam are considering doing this. Armenia, Belgium, Germany, Hungary, Lithuania, Mexico, Netherlands, Slovenia, Spain, Sweden, Switzerland, and United Kingdom have nuclear reactors but currently no advanced proposals for expansion.. Sweden and Germany have decided on a nuclear power phase-out, but depending on the September 2005 elections Germany may reverse its decision.
According to the EIA and the IEA, nuclear power is projected to have a slightly declining 5-10% share of world energy production until 2025, assuming that fossil fuel production can continue to expand rapidly (which is controversial)