The Salem 2 reactor originally went offline June 28 at PSEG Nuclear's Artificial Island generating complex in Lower Alloways Creek Township.
LOWER ALLOWAYS CREEK TWP. -- The Salem 2 nuclear reactor was back in service briefly Monday before a protection system in its generator indicated there might be a problem and shut down the plant again.
The plant had begun sending out electricity to the regional power grid at 6:35 a.m., according to Joe Delmar, spokesman for the plant's operator, PSEG Nuclear.
The plant automatically shut down again at 1:50 p.m. Monday.
The cause of this shutdown was under investigation, Delmar said.
The Salem 2 reactor automatically tripped off-line on June 28 after its generator shut down because of an alarm indicating some sort of problem.
After extensive troubleshooting, it was determined that rainwater had leaked through gaskets on the electrical system for the generator. The area where the problem was found is located on the plant site between the generator and the main transformer.
Operators installed an enhanced monitoring system to detect any future problems before they cause the plant to shut down.
Operators initially brought the plant back on July 4 for about eight hours, but when there was an indication there still might be a problem in the generator, the plant was shut down and new inspections conducted, according to Delmar.
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Outside nuclear industry experts were also brought in to to help.
With the new inspections complete, no issues were found and the reactor was restarted Monday.
What caused the latest shutdown was not clear.
The generator is on the non-nuclear side of the plant.
Salem 2 is one of three reactors operated by PSEG Nuclear at its Artificial Island generating station in Lower Alloways Creek Township, Salem County.
Salem Unit 1 remains out of service as operators continue repairs on bolts in the reactor core.
The third unit at the Island, Hope Creek, remains operating at full power.
The three plants comprise the second-largest commercial nuclear generating complex in the U.S.
Bill Gallo Jr. may be reached at bgallo@njadvancemedia.com. Follow Bill Gallo Jr. on Twitter @bgallojr. Find NJ.com on Facebook.