A new law has been attached to the budget reconciliation bill for 1988. It directs the Department of Energy (DOE) to stop exploratory work at two of three sites already chosen as candidates for a waste repository. From now on, the investigation is to focus exclusively on a third site at Yucca Mountain, a desert area of volcanic tuff about 110 miles from Las Vegas. It will become the national burial ground for all spent reactor fuel, unless researchers find in the next 5 to 7 years that it is not environmentally fit. If the Nevada site fails to measure up, the secretary of energy is directed to return to Congress for further instructions.