The nuclear agency said that at the time the reactor was built in the 1950s, the area was remote but is now surrounded by San Diego suburbs. The reactor is now permanently shut down.
The uranium was located in a "shuttered General Atomics research reactor facility in Torrey Pines Mesa," according to NBCSandiego's media partner the North County Times, which cited an unnamed U.S. government official. According to the Nuclear Regulatory Commission, General Atomics was authorized to decontaminate two reactors in San Diego County.
The National Nuclear Security Administration disclosed the removal Monday in a press release without revealing the name of the research facility.
The agency said nearly 60 kilograms of enriched uranium was moved during three weeks in August and September in three convoys to an unspecified secure federal facility nearly 1,000 miles from San Diego. The Idaho National Laboratory is 961 miles from San Diego.