NRC debates extending life of aging US nuclear plants

Nature : Although 20% of US electricity is generated by nuclear power plants, most of the reactors producing that energy are getting old. Many were built in the 1970s and 1980s with a life expectancy of 40 years. The US Nuclear Regulatory Commission has already renewed the licenses of 81 reactors so they can continue running for another 20 years, and now the NRC is considering extending some licenses yet another 20 years. Despite a slew of increasingly sophisticated maintenance inspections to look for defects and signs of wear and tear, questions have been raised over how materials age and the durability of parts that may be hidden from view. Moreover, because of economic constraints, many power companies have been investing only the bare minimum to maintain and upgrade their nuclear plants. It would be better to build new plants with safer and more modern designs than to push old ones past their limits, according to former NRC chair Allison Macfarlane.