AIKEN, South Carolina, July 10 -- The U.S. Department of Energy Savannah River Site issued the following news release: * * * SRS Completes Major Construction Milestone on Another Mega-Size Disposal Unit With 25 wall sections, 208 support columns, and seven roof sections, all concrete construction on another mega-size disposal unit has been finished at the U.S. Department of Energy's (DOE) Savannah River Site (SRS). Saltstone Disposal Unit (SDU) 11 will hold over 33 million gallons of saltsto  more