"YORK, PA -- Roughly 50 workers at Peach Bottom Atomic Power Station were exposed to low levels of radiation early Tuesday after a discharge of contaminated steam."
"At 1 a.m. that morning, workers were loosening a two-inch vent on top of the Unit 2 reactor vessel head when a 'puff' of radioactive steam escaped from a flange, said Neil Sheehan, a spokesman for the U.S. Nuclear Regulatory Commission.
Radiation monitoring alarms sounded as workers, dressed in bright yellow radiation-protection suits, hurried to close the vent. In total, the length of the release lasted about 2 minutes.
The reactor is offline for a planned refueling outage. About 2,000 contracted or outage workers at the plant will spend the next several weeks completing maintenance work and replacing nearly one-third of the reactor's fuel."