(AP) — Two “mischievous” teenage boys jumped a security fence at a research reactor in the San Francisco Bay Area but there was no threat to the facility that uses highly enriched uranium that could be used to make a nuclear bomb, authorities said Friday.

The trespassers jumped a security perimeter fence Wednesday at the Vallecitos reactor in Alameda County, a sprawling site about 40 miles (64 kilometers) east of San Francisco, the U.S. Nuclear Regulatory Commission said in a security threat notice posted on its website.

They left the area when approached by security, the commission said.
Alameda County Sheriff Sgt. Ray Kelly said Friday officials located the teenagers and spoke to them and their parents.

“There was no foul play suspected or ill intent toward the facility,” Kelly said.

The reactor is a venture between General Electric Co and Hitachi Ltd.
GE said in a release that the boys did not breach the inner perimeter fence or access any operational areas and were immediately approached by security.

The security breach was troubling nonetheless, especially given the danger of the fuel there, said Edwin Lyman, acting director of the Nuclear Safety Project at the non-profit Union of Concerned Scientists watchdog group in Washington.

The Bay Area site is one of few in the country working with highly-enriched uranium, of the kind that can be used in nuclear bombs.

“I do think this troubling incident has revealed a vulnerability in the security at research and test reactors,” Lyman said. “The NRC’s security requirements for such reactors are far too lax, even for those in densely populated urban areas or those that store nuclear bomb-grade material.”

The NRC has sought to increase security at nuclear sites since the Sept. 11, 2001 attacks, for fear of sabotage or theft of radioactive fuel by terrorists.