Cons+of+nuclear+energy


 * Cons ||
 * * Since the first commercial reactor started up in 1957, nuclear plants have produced about 65,000 metric tons of spent fuel, which is now stored at reactors across the nation. When fuel is unloaded from a reactor, it is extremely hot and highly radioactive. It goes into specially designed cooling pools, where it remains under at least 20 feet of water for a minimum of several years. But there are safety limits on how densely spent fuel can be packed into cooling pools without starting a chain reaction that could cause an accident. As a result, NRC has given 38 nuclear plants permission to build dry cask storage on-site for older, cooler fuel because their spent-fuel pools are full or nearly full.
 * Spent fuel is transported in massive steel casks that measure four to eight feet in diameter, have walls five to 15 inches thick and contain materials that shield the environment from radioactivity. One cask used for shipment by truck holds up to nine bundles of fuel rods and weighs up to 25 tons; a rail shipment cask holds several dozen bundles and can weigh 150 tons. Casks must withstand a range of forces in testing, including a 30-foot drop onto reinforced concrete, a 40-inch drop onto a steel spike, a 30-minute fully engulfing fire and submersion under water for eight hours.