BUCHANAN, N.Y. (CBSNewYork/AP) — One of the Indian Point nuclear power plant‘s reactors was shut down Saturday after several control rods lost power, the plant owner said, marking the latest in a series of mishaps at the suburban New York plant this year.

Control room operators safely shut down the Indian Point 2 reactor around 5:30 p.m., owner Entergy Corp. said in a statement, adding the reactor did what it’s intended to do if control rods lose electricity.

“All equipment at unit 2 operated as designed and the plant safely shut down,” the statement said.

The company said it’s not yet clear what caused the power problem.

Entergy reported no radiation was released into the environment, said Gov. Andrew Cuomo, who has complained that there have been too many problems at Indian Point and has called for closing down the plant. The state Department of Public Service was headed to investigate and monitor the situation at the two-reactor plant in Buchanan, about 30 miles north of midtown Manhattan.

Federal Nuclear Regulatory Commission representatives didn’t immediately responded to a request for comment on the shutdown.

The plant’s other reactor, Indian Point 3, remained running. Together, the two reactors supply about one-fourth of the power used in New York City and Westchester County.

The plant has experienced a number of unplanned shutdowns this year. Indian Point 3 was shut down for a time in July after a water pump problem, and in June because of an electrical disturbance at a switch yard outside the plant. A water-system alarm failure in January led workers to start shutting down one of the reactors, although repairs were made and the shutdown reversed.

And in May, a transformer failure and a fire on the non-nuclear side of the plant forced an automatic shutdown of Indian Point 3 that lasted 16 days. The fire was extinguished quickly and caused no safety problems at the reactor, but it spilled about 3,000 gallons of transformer fluid into the Hudson River. Federal regulators found that workers at the plant responded appropriately to the transformer fire, which was blamed on insulation failure.

Dating to the 1970s, both of Indian Point’s reactors are up for relicensing. That has sparked some objections from state and city officials, who cite worries ranging from its effect on Hudson River fish larvae to the safety implications of a nuclear plant so close to New York City.

Federal officials and New Orleans-based Entergy have said the plant is safe, and Entergy has pointed to $1 billion in safety enhancements over the last decade. The company also has noted that the plant generates more than 10 percent of the state’s energy supply, while producing little air pollution or emissions contributing to global warming.

Saturday’s shutdown came about two hours before a power outage darkened a stretch of the Hudson Valley and nearby Pennsylvania, about 45 miles away from Indian Point. But the utility involved in that outage, traced to an equipment malfunction in an electric transmission substation, said it had no relation to the power problem at Indian Point.

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