The Hanford Nuclear Reservation sits on the plains of eastern Washington. The site is nearly 600 square miles in area and has been largely closed to the public for the past 70 years. Late last year, though, it became part of the Manhattan Project National Historical Park. A total of nine reactors operated at Hanford, and though they are now decommissioned, the reactors have left behind 56 million gallons of radioactive waste. Recent reports [indicate] new breaches in the tanks holding the nuclear waste. Workers on the site have been sickened too, suggesting that the rush to designate Hanford as a park may have been premature. The government has hired private contractors to build a plant that will solidify the waste and prepare it for permanent safe storage. The project will cost an astonishing $110 billion ... making it what many believe to be the most expensive, and extensive, environmental remediation project in the world. Completion is about five decades away. In 2013, construction of the Waste Treatment Plant - which will pump nuclear sludge out of the tanks and turn them into a hardened, glasslike substance - was slow. Whistleblowers, meanwhile, were alleging that private contractors had neglected safety and engineering concerns. Observers likened the place to a nuclear tinderbox. "America's Fukushima?" asked the resulting Newsweek cover story. [One containment tank] was already known to be leaking toxic sludge into the soil. Now a second double-shelled tank ... is believed to be leaking as well.