Test site scare blamed on training prop

One of them found what appeared to be an explosive device poking from beneath a bush near the massive, low-lying fortress at the Nevada National Security Site.

What officials said Wednesday was a "training prop with black electrical tape at both ends" turned out to be a false alarm. But it triggered an intense emergency response with widespread alert of news outlets Tuesday for a mysterious incident in a high-security area in the center of the remote former Nevada Test Site.

The event, or nonevent as it was, occurred among Joshua trees and creosote bushes outside the thick-walled complex known as the Device Assembly Facility.

That’s where machine-gun towers overlook earth-covered chambers where nuclear devices can be handled and inspected.

The concrete-and-steel complex stretches the length of two football fields. It has a maze of hallways and 90 metal doors, each leading to another corridor to one of the 20 clean bays or to five "Gravel Gerties" – soil-topped round rooms with steel-cabled ceilings and reinforced concrete walls.

When the $100 million facility opened in 1996 after a decade in construction that began in the last years of the Cold War, scientists calculated the rooms were sturdy enough to contain highly toxic plutonium in an accidental detonation. Tests show the roof would blow off, but soil and debris would fall back into the structures, or "Gerties," named after a character from the Dick Tracy comic strip.

The incident-turned-drill Tuesday worked as planned, much to the satisfaction of the site’s acting manager, Steven J. Lawrence.

"While this event turned out to be a false alarm, it clearly demonstrated that our established emergency management processes and procedures can and do work," Lawrence said in a news release from the National Nuclear Security Administration, the branch of the Department of Energy that runs the Rhode Island-size test site, off U.S. Highway 95, about 65 miles northwest of Las Vegas.

"As with any event there will be lessons learned, but overall I am very proud of how our workforce responded," Lawrence said.

Site spokesman Darwin Morgan said the response of emergency crews and law enforcement personnel began shortly before 4 p.m. Tuesday when a guard on patrol found the black-taped item in a stretch of desert outside the facility.

"Following established safety procedures, the individual backed away and reported the suspicious item," the news release said. "A safety perimeter was established, and all occupants within the DAF (Device Assembly Facility) were ordered to shelter-in-place. As trained personnel arrived to assess the item, a determination was made to evacuate occupants."

The scare lasted more than four hours, until 8:30 p.m., when responders determined the item was harmless.

"While it is not fully certain, it is suspected that the prop was dropped during a past training exercise," the news release said.

Speaking by telephone Wednesday from the agency’s Nevada Site Office in North Las Vegas, Morgan said, "By order, when we have something that’s unidentified and suspicious, we have to follow the procedures that are in place, and that is doing the response that we had. People did exactly what they were supposed to when they were supposed to do it."

Contact reporter Keith Rogers at krogers@reviewjournal.com or 702-383-0308.