Three Mile Island is back in the news after a small amount of leaked radiation was detected on November 21 at the nuclear power plant made infamous by a meltdown in 1979. The leak was quickly contained, but the debate about nuclear energy keeps growing.
Three Mile Island Overview: Human error, and equipment and design flaws triggered the worst nuclear accident in U.S. history at this Harrisburg, Pennsylvania nuclear plant. The severe core meltdown began about 4 am on March 28, 1979, with a failure in the non‑nuclear section. A relief valve failed to close, and operators mistakenly reduced the flow of coolant through the core. Fortunately, there was no breach of the walls of the containment building. Subsequent studies by government agencies and independent groups estimated the average dose to about 2 million people in the Three Mile Island area was 1 to 8 millirems comparable to a chest x-ray of 6 millirems. Investigators concluded that most of the radiation was contained, and that the release had negligible effects on individual and environmental health. Still, the construction of new U.S. nuclear power plants came to a halt.
Advantages of Nuclear Energy: The advantages of nuclear energy keep the debate going as society weighs the small risk of a big disaster. As Scientific American puts it, nuclear power is reliable, secure and eco-friendly. Nuclear plants can generate electricity almost 90% of the time and could reduce foreign fuel dependence. By generating electricity from uranium, they produce less greenhouse gases than burning fossil fuels. As nations struggle to reduce global warming emissions, nuclear reactors present the advantages of emitting almost no carbon while they operate and having low life-cycle emissions. Most experts agree nuclear power should be considered in conjunction with other strategies including increased efficiency and renewables. Even critics may have to accept the current trends as the U.S. considers building up to 26 new reactors while 51 of the 104 currently operating have received clearance to operate another 20 years or more and the rest are under review or expected to apply.
Challenges of Nuclear Energy: The advantages of nuclear power need to surmount the economic, safety, security, and waste disposal challenges. Nuclear plants are relatively cheap to operate but have much higher capital costs at about $2,000 dollars a kilowatt compared to about $500 for a natural gas plant based on estimates by MIT’s Laboratory for Energy and the Environment.There should be no complacency about safety. U.S. nuclear reactors have had to shut down for a year or more for repairs or other safety improvements at least 46 times according to the Union of Concerned Scientists. The National Regulatory Commission’s analysis of events that could lead to a nuclear accident shows that U.S. nuclear reactors averaged seven such events per year between 1993 and 2004. Waste disposal is another cause for concern given the dangers of radiation and weapons proliferation.
Sources: Scientific American, Nuclear Regulatory Commission, Union for Concerned Scientists