"For six years, workers processed nuclear waste at a plant outside Buffalo. In its short life, the West Valley Demonstration Project polluted soil, air and water, and may have sickened employees. Four decades later, hundreds of cleanup workers are still at the site decontaminating buildings that will eventually be torn down. Now, workers are preparing to install a massive underground wall designed to stop the spread of a radioactive plume that threatens the region's groundwater. As the West Valley cleanup nears completion," an environmental disaster is leading a new understanding of how to deal with nuclear waste.