Workers have begun demolishing the massive X-333 Process Building at the Portsmouth Site in Ohio, the Department of Energy’s Office of Environmental Management announced. The largest of three former uranium enrichment process buildings at Portsmouth, the X-333 building is the second of the three buildings to be demolished at the site and is a priority for DOE-EM.

In the 1950s, the U.S. Department of Energy constructed the Portsmouth Gaseous Diffusion Plant in rural southern Ohio to enrich uranium, alongside two other federally owned and managed facilities in Oak Ridge, Tenn., and Paducah, Ky. The Cold War-era plant was built as a self-sufficient industrial city with more than 400 buildings and facilities centered around three massive gaseous diffusion process buildings that could enrich the level of the uranium-235 isotope for nuclear fuel in the defense and energy sectors.