Siren sounds false alarm for Pa. nuke plant

FILE - This file photo from March 30, 1979 shows a cooling tower of the Three Mile Island nuclear power plant near Harrisburg, Pa., as it looms behind an abandoned playground. The partial meltdown at Three Mile Island nuclear plant in 1979 routed more than 180,000 people living within 50 miles of the plant. (AP Photo/Barry Thumma, File)

July 14, 2011 7:12:10 PM PDT
People living in the central Pennsylvania borough of Hummelstown got a scare when a Three Mile Island warning siren briefly sounded but officials say it was a false alarm.

The siren is one of 96 located in the 10-mile radius around the nuclear power plant. It sounded for about 30 seconds shortly after 1 p.m.Thursday.

Dauphin County Emergency Management Agency officials were notified through an automated monitoring network that the alarm went off. They're working with Exelon, the operator of Three Mile Island, to determine the cause of the false alarm.

Exelon plans to replace all 96 sirens later this year with newer, louder sirens, each with battery backup power. They say the control and monitoring systems for the sirens will also be replaced.