The Savannah River Site (SRS) is a nuclear reservation in the United States in the state of South Carolina, located on land in Aiken, Allendale, and Barnwell counties adjacent to the Savannah River, 25 miles (40 km) southeast of Augusta, Georgia. The site was built during the 1950s to refine nuclear materials for deployment in nuclear weapons. It covers 310 square miles (800 km2) and employs more than 10,000 people. The Savannah River Site (SRS) is a nuclear reservation in the United States in the state of South Carolina, located on land in Aiken, Allendale, and Barnwell counties adjacent to the Savannah River, 25 miles (40 km) southeast of Augusta, Georgia. The site was built during the 1950s to refine nuclear materials for deployment in nuclear weapons. It covers 310 square miles (800 km2) and employs more than 10,000 people. It is owned by the U.S. Department of Energy (DOE). The management and operating contract is held by Savannah River Nuclear Solutions LLC (SRNS), and the Liquid Waste Operations contract is held by Savannah River Remediation, which is a team of companies led by AECOM. A major focus is cleanup activities related to work done in the past for American nuclear buildup. Currently none of the reactors on-site are operating (see list of nuclear reactors), although two of the reactor buildings are being used to consolidate and store nuclear materials. SRS is also home to the Savannah River National Laboratory and the USA's only operating radiochemical separations facility. Its tritium facilities are also the United States' only source of tritium, an essential component in nuclear weapons. The USA's only mixed oxide fuel (MOX) manufacturing plant was being constructed at SRS, construction was terminated in February 2019.. Construction was overseen by the National Nuclear Security Administration. The MOX facility was intended to convert legacy weapons-grade plutonium into fuel suitable for commercial power reactors.