Arizona nuclear plant sealed off due to pipe bomb

PHOENIX (Reuters) - The Palo Verde nuclear power plant, the largest in the United States, was sealed off on Friday after security guards found a pipe bomb in a worker's pickup truck as he tried to enter the facility, officials said.

The Maricopa County Sheriff's Department said the small bomb was found in "plain view" in the bed of a pickup truck of a contract worker around 6 a.m. local time (1300 GMT).

The FBI and the sheriff's department are investigating but have yet to say whether the worker intended to explode the bomb, or how big an explosion could have been caused.

A man driving the pickup, an engineer with access to sensitive areas of the plant, was detained and questioned by lawmen, including the FBI. And his apartment in Phoenix was searched on Friday afternoon after he gave his consent, said Capt. Paul Chagolla of the sheriff's department.

The result of the search was not yet known.

There was "no indication at this point if he intended" to do harm to anyone, said Chagolla.

The pipe bomb was removed from Palo Verde, which is located about 50 miles west of Phoenix.

"There is no threat to the plant," said Jim McDonald, spokesman for Arizona Public Service, which operates Palo Verde. He added that the public was not in danger.

Chagolla said, "Our examination and preliminary testing shows it is a viable improvised explosive device," commonly known as a pipe bomb.

The plant, which has three nuclear reactors, continued to operate, APS said.

McDonald said the engineer has worked at Palo Verde for about a year and has mainly worked in the administrative portion of the plant. The last time he worked in the "protected area" of the plant was October 17.

Victor Dricks, spokesman for the U.S. Nuclear Regulatory Commission, said the NRC was "monitoring the response of the operator" but did not see any threat of danger to the public.

APS chief nuclear officer Randy Edington said, "Our security personnel acted cautiously and appropriately and demonstrated that our security processes worked as designed."

McDonald added that every time a person enters the plant, the person and vehicle undergo an "extensive" inspection.

"It's not an accident they found it," said McDonald. "It's not like an inspection you go through at the airport. The security is highly trained and they are damned good at what they do and they did it today."

The closest homes are less than a mile from the reactors, and have been built in the past several years. Palo Verde has been operating for more than two decades.

Two of the three reactors at Palo Verde were not in operation Friday morning. One is in a refueling that will continue until the second half of December, and another was to return to the power grid as early as later today, an APS spokeswoman said. The third reactor is fully operating, she said.