In an amendment to a 1998 record of decision, the Department of Energy is expanding the available space at its Waste Isolation Pilot Plant deep geological repository for defense-related radioactive waste, and is also now planning to accept waste at the facility for 50 more years than previously planned. The amended decision, which was signed on August 18 by Tim Walsh, assistant secretary for Environmental Management, commits the DOE to a WIPP operating horizon extending to about 2083.