New York Times: Standing at the lip of what might be Americas most valuable hole in the ground, Rodney A. Baltzer cataloged the features that he said would isolate the radioactive waste to be buried here for thousands of years. First, Mr. Baltzer said, there is a base layer of nearly waterproof clay, then a layer of concrete reinforced with steel and then three layers of plastic. When the waste, loaded into concrete containers, fills the pit, he said, it will be topped by a 40-foot-thick covering cap that includes...