By Preston Peeden
KNOXVILLE, Tennessee (Reuters) - Jury selection began on Monday in the trial of an elderly nun and two other environmental activists who broke into a supposedly secure facility that stores enriched uranium for nuclear bombs, embarrassing the U.S. government.
The three activists are charged with sabotage and destruction of government property after they cut through several fences last July to reach the heavily guarded Y-12 National Security Complex in Oak Ridge, Tennessee.
They admitted to walking for two hours through the complex - which prosecutors described as the "Fort Knox" of U.S. nuclear installations - and spray painted slogans and hammered on the walls of an enriched uranium facility. Fort Knox is the heavily guarded U.S. military base where gold reserves are stored.
When a guard finally confronted them they offered him food and began singing.
The activists, Michael Walli, Greg Boertje-Obed and nun Melissa Kirby, who was 82 at the time of the incident, were in a Tennessee federal court on Monday as more than 70 people were considered for the jury. Jury selection had not been completed by mid afternoon on Monday.
Walli wore a blue t-shirt that said "Ground the drones." The other two were not visible to journalists watching the proceedings on closed circuit television in a nearby courtroom.
The breach embarrassed the U.S. government and sparked investigations by Congress and the Energy Department, which oversees nuclear facilities.
A Department of Energy inspector general report in August last year found "troubling displays of ineptitude" at the complex.
Shortly after the breach, the top security official at the National Nuclear Security Agency and two other federal officials were reassigned. In addition, top officials at WSI, the international security company that provided security at Oak Ridge, were removed and officers were fired, demoted or suspended.
Thomas D'Agostino, then the security agency administrator, said staff involved in the incident had been removed, cameras fixed, and patrolling and training improved.
In January, the security agency named a new group to manage security at the site, Consolidated Nuclear Security LLC. The group replaced Babcock & Wilcox Co, which had contracted some of security work to WSI, a unit of G4S.
Also that month D'Agostino stepped down, six months after the peace activists broke into Y-12. The agency said his departure had nothing to do with the breach.
The Oak Ridge facility is the primary U.S. site for processing and storage of enriched uranium and one of the primary manufacturing facilities for the U.S. nuclear weapons program.
(Reporting By Preston Peeden; Writing by Greg McCune; Editing by Steve Orlofsky)