OAK RIDGE, Tenn. (WATE) — The Department of Energy’s Office of Environmental Management is making necessary upgrades to keep a nuclear reactor that hasn’t been in use for almost 50 years safe until it can be decommissioned.

The improvements to the Molten Salt Reactor Experiment will save approximately $5 million in annual operating costs.

“We have the important responsibility of keeping it safe until major cleanup operations begin,” said Nathan Felosi, the Office of Environmental Management’s Oak Ridge National Laboratory portfolio federal project director. “The latest round of projects is making sure that’s the case and achieving considerable cost savings to taxpayers.”

MSRE, located on the ORNL campus, is one of more than 200 facilities in Oak Ridge that no longer support ongoing missions. Numerous upgrades are needed to the reactor including fluorine gas tanks, a ventilation system, and a new roof to protect from key systems.

Oak Ridge Office of Environmental Management contractor UCOR is making upgrades and modifications that minimize maintenance costs, reduce risks of injury and exposure to personnel, provide reliable electric service to key systems, and eventually eliminate the need for personnel to work at the facility.

The reactor reached full power in 1966 using uranium-235 as fuel.

Two years later, scientists added uranium-233 to demonstrate the design’s flexibility, making it the first reactor in the world to operate with uranium-233. Scientist Glenn Seaborg who discovered plutonium and created uranium-233 came to ORNL to start the reactor.

The facility was used in a short-lived effort to develop a nuclear-powered aircraft in the 1950s. After that initiative was cancelled, focus shifted to using MSRE technology to generate electricity.

MSRE was shut down in 1973.