Arizona Nuclear Plant on Lockdown

Water vapors rise into the air from some of the nine cooling towers at Palo Verde Nuclear Generating Station, seen in this Tuesday, Dec. 7, 1999, file photo near Wintersburg, Ariz. Security officials at the Palo Verde Nuclear Generating Station detained a contract worker with an explosive device in the back of his truck Friday, Nov. 2, 2007 and the plant was put on lockdown. (AP Photo/Jason Wise)

by CHRIS KAHN - Nov 2, 2007

Security officials at the nation's largest nuclear power plant detained a contract worker with a small explosive device in the back of his pickup truck Friday, authorities said.

The worker was stopped and detained at the entrance of the Palo Verde Nuclear Generating Station, said U.S. Nuclear Regulatory Commission spokesman Victor Dricks. Security officials then put the nuclear station on lockdown, prohibiting anyone from entering or leaving the facility.

Authorities described the device as a small capped pipe that contained suspicious residue.

Capt. Paul Chagolla with the Maricopa County Sheriff's Office said sheriff's officials rendered the device safe and that investigators were interviewing the worker.

"Our Security personnel acted cautiously and appropriately, demonstrating that our security process and procedures work as designed," said Randy Edington, the chief nuclear officer for plant operator Arizona Public Service Co., in a statement.

The incident was considered an "unusual event" - the lowest of four emergencies the plant can declare, said Jim Melfi, an inspector with the U.S. Nuclear Regulatory Commission.

There was no threat to the public and the station was operating normally, said Palo Verde spokesman Jim McDonald.

Palo Verde, operated by Arizona Public Service Co., is the nation's largest nuclear power plant both in size and capacity. Located in Wintersburg about 50 miles west of downtown Phoenix, the plant supplies electricity to about 4 million customers in Arizona, New Mexico, Texas and California.