A fire in one of the Indian Point nuclear plant main electrical transformers resulted in the forced shutdown of Unit 3 at the facility on May 9.

The fire started at 5:50 p.m. local time on Saturday and it was quickly extinguished by an automated sprinkler system, along with the action of trained onsite personnel. There were no injuries reported and there was no release of radioactivity or threat to the safety of workers or the public, according to Entergy Corp., owner of the plant.

New York Gov. Andrew Cuomo (D), who received a briefing on the plant’s status following the incident, said the fire reignited after it was initially extinguished and was put out for a second time.

“Anything that happens at this plant obviously raises concerns,” Cuomo said during a press conference after the briefing. “This plant is the nuclear plant that is closest to the most densely populated area on the globe. If something goes wrong here, it can go very wrong for a lot of people, so it’s always been a priority for us.”

The event resulted in a secondary problem as well, because the oil-filled transformer ruptured and discharged oil onto the ground. Cuomo said that although the transformer had a containment holding tank, the water and oil exceeded the capacity of the tank and overflowed into the drainage system, which discharges into the Hudson River.

“There is no doubt but that oil did escape from the transformer, there is no doubt that oil did go into the holding tank and exceeded the capacity of the holding tank, and there is no doubt that oil was discharged into the Hudson River. Exactly how much, we don’t know,” Cuomo said.

The New York State Department of Environmental Conservation (DEC) dispatched representatives to the site soon after the incident was reported. Plant workers placed sandbags around drains and release paths. Booms were placed in the water around the discharge pipe to contain any oil that escaped via that route and the situation continues to be monitored.

In March, Indian Point Unit 3—a 1,051-MW pressurized water reactor—underwent a 23-day planned shutdown to renew components and replace fuel in the reactor. The outage was said to have cost $50 million. Work included the overhaul and inspection of one of three low-pressure turbines and one of two main boiler feed pumps, the replacement of one of four reactor coolant pump motors, and the testing and inspection of the Unit 3 reactor containment area.

On May 7, Entergy Corp. reported that control room operators would remove Unit 3 from service to repair a steam leak from a pipe on the non-nuclear side of the plant. Operators began reducing power around 7:00 a.m. that morning, but according to the Nuclear Regulatory Commission Event Notification Report, the plant was online at full power when the transformer incident occurred at 5:50 p.m. on May 9.

The cause of the transformer failure is still under investigation. It is unclear at this point how long the unit will be offline for repairs. Unit 2—a 1,032-MW reactor—remains in operation at 100% power.

Aaron Larson, associate editor (@AaronL_Power, @POWERmagazine)