Sirens will be tested at full volume for four minutes in Westchester, Rockland, Orange and Putnam counties, it said.
In an actual emergency, Entergy said, the sirens would alert the public to tune in to a local Emergency Alert System radio or television station for important information and direction.
These stations are listed in the emergency planning booklet mailed to households and businesses in a 10-mile zone around Indian Point.
For an electronic version of the booklet, click here.
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