Thursday, April 1, 2010
Nuclear waste problem
With Nevada’s Yucca Mountain facility out of the picture as a nuclear waste repository, government nuclear experts say interim measures might be needed for a very long time. 2,700 industry executives, nuclear regulators and other experts recently gathered for a nuclear energy conference in Washington. The goal was to discuss and determine just how many centuries such fuel can be safely stored above ground, and how they should come up with a policy that would not require amendment for many years. The commission currently allows reactors to operate and accumulate waste under a “waste confidence” policy that anticipates that the federal government will have a repository in place by the 2020s. But with the demise of the plan to bury the waste at Yucca Mountain, the commission is working on a new policy. The commission said that nuclear waste can essentially be held safely for a long time above grounds, but this statement is unclear as whether it can be stored for 50 years or 400 years. The Energy Department convened a “blue ribbon commission” to evaluate all options, including new kinds of reactors that could run partly on waste from the old ones, and convert some of the most toxic and longest-lived materials into less troublesome materials. But there is no clear path forward at this point. A new policy should not predict when a repository will open, but show what the limits of safe and secure storage of fuel are. Fuel is now stored in dry casks which are basically steel-lined concrete silos that require no liquid cooling or forced ventilation and those are licensed for 20 years. Metal parts of such casks can begin corroding in weeks if salt hits them. Whether this happens depends partly on the temperature of the cask (it is heated by the waste) and the humidity in the air. The engineer who headed the Yucca program under the Bush administration, Edward F. Sproat III, also attending the conference, said, “you can’t keep that stuff in those canisters forever. They’re not designed that way.” Overall, as global population and energy consumption increase, new solutions need to be implanted, whether it be new reactors which produce less waste and run off old waste, or completely new and environmentally safe methods of disposing of the nuclear waste.