Nuclear plant sirens fail

Breakdown is 3rd since October

Emergency sirens that warn the public of accidents at the Shearon Harris nuclear plant failed last month, federal nuclear regulators reported Thursday.

The Jan. 30 failure of all 81 sirens at the Harris plant in southwestern Wake County is the third time all the sirens have simultaneously failed in the past 18 months. Progress Energy reported the latest malfunction to the Nuclear Regulatory Commission on Monday, two weeks after the incident.

The sirens, mounted on 50-foot poles in the nuclear plant's 10-mile emergency planning zone, are the most conspicuous reminder of the nearby nuclear plant. Their purpose is not only to warn residents of an accident at the plant but also to foster public confidence in the nuclear plant's emergency preparedness system.

About 74,000 people now live within 10 miles of the Shearon Harris plant in a growing area that includes the towns of Apex, Holly Springs, Fuquay-Varina, Moncure and New Hill. The population within the emergency zone has grown by 25 percent since 2000.

The cause of the malfunction was loss of power at the plant's radio transmitter, which would activate the sirens during an emergency.

"The offsite emergency sirens were not capable of being activated," the company said in its notification to the NRC. "It is reasonable to conclude that the sirens had been lost for a period of time between 70 and 80 minutes."

The previous systemwide failures took place in October 2006 -- once for four hours and the next day for three hours.

Progress Energy installed 83 new sirens last year at a cost of $2.5 million. They are equipped with backup batteries to avoid failures during power outages. But the new sirens are still being tested and not yet operating. The failure affected the old sirens that have been used at the plant for two decades.

Testing of the new sirens is expected to conclude in March.

All nuclear power plants in the United States are required to have emergency sirens or some other emergency notification system to alert residents living within 10 miles. Residents within 5 miles of Shearon Harris are also given emergency radios.