Entergy Corp. shut its 1,020-megawatt Indian Point 2 reactor in New York after a transformer explosion, according to a report from the U.S. Nuclear Regulatory Commission.
“We will be investigating the explosion to try to determine the cause,” Jim Steets, a spokesman for Entergy, said in a telephone interview. The incident yesterday at 6:39 p.m. caused the reactor to automatically shut down.
Jerry Nappi, a spokesman for the plant, said there was a replacement unit on site, which could lessen downtime for repairs. The failed unit was installed in 2006, contained PCB-free oil and was designed to last at least 30 years, Nappi said in a telephone interview.
“Clearly there is an issue that needs to be looked at with what happened to this one because obviously it didn’t reach anywhere near that length,” Nappi said.
Siemens AG, Europe’s largest engineering company, built the transformers for Unit 2, Nappi said. “It could be something external to the transformer that caused it to fail,” he said.
The plant is in “cold” shutdown, meaning it will take longer for the unit to return power to the electricity grid because it is not at operating pressure and temperature. Sometimes a reactor can be taken offline to “hot” standby, where it is quicker to restart power generation.
A transformer exploded at the plant’s Unit 3 in 2007, Neil Sheehan, a spokesman for the NRC, said in a telephone interview. Each reactor has two main transformers that boost current before it reaches the electrical grid.
“They monitor these transformers and they can tell when they’re starting to degrade but sometimes they can fail suddenly,” Sheehan said.
The plant’s Unit 3 reactor was not affected by yesterday’s explosion and is operating at full capacity at the plant 24 miles (39 kilometers) north of New York City, Steets said.
The plant’s Unit 1 reactor was shut in 1974 because the emergency core cooling system did not meet regulatory requirements, the NRC said. It began service in 1962.