The US Department of Energy (DOE) has approved construction of three main buildings of the $6.5bn Uranium Processing Facility (UPF) project in Oak Ridge, Tennessee. The department’s National Nuclear Security Administration (NNSA) can now begin construction on the Main Process Building (MPB), Salvage & Accountability Building (SAB), and Process Support Facilities (PSF) subprojects. The three-story MPB will house enriched uranium operations while the SAB and PSF buildings are expected to support operations in the MPB. NNSA is aiming to complete UPF by the end of 2025, subject to stable funding for the duration of the project. In January 2013, Consolidated Nuclear Security, a company consisting of Bechtel, Lockheed Martin Services, ATK Launch Systems, and SOC, was selected for designing and overseeing construction of the project. NNSA said UPF will replace an ageing plant built during the early phase of the Cold War. The UPF will be a modern, more efficient, and safer facility compared with the existing plant for carrying out highly-enriched uranium operations at the Y-12 National Security Complex in Oak Ridge. NNSA is building the UPF project through a series of seven subprojects, two of which were executed on time and under budget. Two more were in progress before authorisation of the three main buildings. NNSA revealed that the project had reached 90% design completion last September ahead of seeking construction authorisation for the three facilities from DOE.