Public concerns about nuclear power have traditionally centered on two issues: the risk of widespread radioactive fallout from an accident and the hazards of nuclear waste. (Since 9/11, security risk has emerged as a third major worry.) My research shows such fears are unfounded. A Chernobyl cannot happen here—a survey by the Nuclear Regulatory Commission (NRC) established that our reactors are free of the design flaws that permitted Chernobyl to explode, and in the United States a typical reactor core is surrounded by multiple enclosures to block the escape of radioactive material even in the event of an accident. Chernobyl had no such containment.
Our worst commercial reactor accident, at Three Mile Island 2, was said to be successfully contained despite a partial meltdown, according to the NRC’s investigation. A minute quantity of radioactive gas was intentionally vented from the reactor building, but several independent, peer-reviewed studies have not ascertained any health effects attributable to exposure. Since then, U.S. regulations have instituted many additional safety measures. The reactors that will be used by NRG in the South Texas Project are of a type dubbed the Advanced Boiling Water Reactor (pdf), the latest iteration of a thoroughly vetted design that has been safely used for a decades, the light water reactor. These reactors have the intriguing feature that the water used to cool the core and run the generating turbine is also essential to maintaining a nuclear chain reaction. Briefly, fissioning atoms in the nuclear reactor’s fuel emit neutrons that are traveling too fast to efficiently cause other atoms to fission. The water slows the neutrons, allowing the chain reaction to continue at a steady pace. In case of an accident, multiple systems would keep cooling water flowing to the core, and control rods would quickly drop, automatically shutting down the nuclear reactions.
What about the waste? Uranium is an extremely dense source of energy, and the volume of waste is therefore small. According to David Bradish, a data analyst at the Nuclear Energy Institute, a nuclear fuel pellet measures 0.07 cubic inch (about the size of your fingertip) and contains the energy equivalent of 1,780 pounds of coal. The nation’s 104 reactors generate roughly 800 billion kilowatt-hours a year and contribute about 2,000 tons of spent nuclear fuel a year. By contrast, U.S. coal combustion produces some 100 million tons of toxic material annually.
At nuclear plants, spent fuel is currently being transferred from pools to robust concrete casks, where it can be secured for about a century. But this spent fuel, which retains more than 95 percent of its energy, can be reprocessed to make new fuel, reducing the ultimate volume of waste by more than 60 percent. The National Academy of Sciences has given the nod to long-term disposal of spent fuel in canisters that will be sealed deep inside a mountain near the vast, remote Nevada Test Site, where hundreds of atomic bombs were once exploded.
NRG is currently waiting for a go-ahead from the NRC to construct and operate its new pair of reactors, scheduled to come online in 2014 and 2015. Several other companies are now lining up to submit their own new reactor plans. NRG’s approval is expected no sooner than 2011, but should it come, it could signal the start of a nuclear renaissance and of substantial reductions in America’s carbon footprint.
