The Tennessee Historical Commission has given the go-ahead for the demolition of Buildings 9207 and 9210 of the Biology Complex at the Y-12 National Security Complex.

The buildings date back to the top-secret Manhattan Project, a World War II-era program that developed and built the world’s first atomic weapons. The buildings have fallen into disrepair and have leaky roofs, fallen exterior tiles and asbestos issues. The Biology Complex had originally been used for recovery of uranium from process streams, and later housed researchers doing work on the genetic effects of radiation.

Demolition is being overseen by the U.S. Department of Energy’s Oak Ridge Office of Environmental Management. Deactivation and demolition of the complex would take three to four years and is expected to cost $125 million. The project includes asbestos abatement.

According to the U.S. Department of Energy, the Biology Complex formerly housed more people with doctorates than anywhere else in the world. Among the biological advancements made at the complex was the discovery of the Y chromosome.

The DOE’s National Nuclear Security Administration, which oversees operations at Y-12, is considering building a lithium production facility on the site, which could begin operations by 2030.