A reactor at Pennsylvania’s Susquehanna nuclear plant went offline Tuesday to fix a small coolant leak.
The plant described leakage into the drywell as caused by a leak at a “welded joint on the ‘A’ reactor recirculation piping where a 4 inch blank-flanged pipe for chemical decontamination connects to the 28 inch pipe,” officials said in a report to the Nuclear Regulatory Commission (NRC).
Unit 2 remains online. Both units are General Electric Type 4 boiling water reactors. A subsidiary of PPL operates the plant northeast of Harrisburg, PA.
In a statement, PPL Chief Nuclear Officer Timothy Rausch said the condition did not affect public safety.
“We made the prudent decision to shut down the unit while the leak is small and will return it to service after we make the needed repairs,” he said.
The plant has suffered incidents over the past year as Unit 1’s main turbine had cracks in blades that are similar to, but less extensive than, damage discovered and repaired in 2011.
PPL replaced one row of blades on the Unit 1 turbine during a refueling and maintenance outage.
In addition, last September, Unit 1 ended up with a safety downgrade from the NRC.
The downgrade was the result of a performance review in August 2011 because PPL had to manually shut down the reactor in January and March due to steam leaks, which came on the heels of a July 2010 flooding incident that required a manual shutdown, NRC officials said.