Indian Point tested its emergency siren system Wednesday morning.

The Buchanan nuclear power plant's test sounded successfully across Westchester, Rockland, Putnam and Orange counties.

The goal of the 172 siren test was to make sure the system would work if there ever is an emergency.

Plant officials stress that the sirens are not a signal to evacuate. In an actual emergency, the sirens would sound to alert the public to tune in to a local EAS radio or television station for important information and direction.

The plant generates as much as 30 percent of the electricity used in New York City and Westchester County. The plant is scheduled to be taken completely offline by 2021 after an agreement between Gov. Andrew Cuomo's office and Entergy, the company that owns Indian Point. Westchester County Executive Rob Astorino has sued the state to keep the plant open.