(Reuters) - A transformer failure and fire caused a unit at Indian Point nuclear plant north of New York City to be shut down on Saturday, and people nearby reported seeing an explosion and smoke at the plant.
The plant at Buchanan in New York state was stable and there was no danger to the public or employees, said Entergy Corp, the company that operates the facility.
Several emergency calls reported a loud noise at the plant, which is located about 40 miles (65 km) north of New York City on the east bank of the Hudson River, a New York State police spokesman said.
The transformer fire was extinguished with no damage to the reactor, a spokesman for Entergy said.
The fire, which occurred at around 6 p.m. EDT (2200 GMT), triggered the closure of the plant's Unit 3 reactor, but the other Unit 2 continues to operate, spokesman Jerry Nappi said.
He said there was no information yet as to what caused the transformer failure.
The fire was put out by the sprinkler system at the transformer and on-site personnel, he said. The transformers are located around 300-400 feet (90-120 meters) away from the reactor.
Several people tweeted from near Indian Point that they saw a big explosion.
"I was a mile away from Indian Point when the transformer explosion occurred. Yikes..." said one Twitter user, Kevin Daly.
Entergy said in a Twitter message that there had been "no threat to public safety at any time."
The police spokesman said no injuries were reported at the site.
The plant has two units, Unit 2 and Unit 3.
On Friday, Entergy returned the 1,031-megawatt Unit 3 back to service after shutting it down the previous day to repair a steam leak on the non-nuclear side of the plant.
The plant has 1,050 employees, according to Entergy.
The plant, whose origin dates back to the 1960s, has long been controversial because of its proximity to the United States' largest city.
Indian Point is one of 99 nuclear power plants licensed to operate in the United States and which generate about 20 percent of U.S. electricity use, according to the U.S. Nuclear Regulatory Commission website.
Environmental groups that have called for the plant's permanent shutdown include Hudson River defender Clearwater, the New York Public Interest Research Group and clean water advocate Riverkeeper.
(Reporting by Scott DiSavino, Victoria Cavaliere, Lisa Lambert and Jonathan Oatis; Writing by Alex Dobuzinskis and Frances Kerry; Editing by Christian Plumb)