New Jersey's Salem 2 nuclear reactor shut down shortly after it came back in service after a generator indicated there might be a problem.
PSEG Nuclear spokesman Joe Delmar tells NJ.com the plant had begun sending electricity to the regional power grid at 6:35 a.m. Monday, but automatically shut down again at 1:50 p.m.
The cause of the shutdown at the Lower Alloways Creek plant is under investigation.
The reactor automatically tripped offline on June 28 after its generator shut down because of an alarm. It was determined that rainwater had leaked through gaskets on the electrical system for the generator.
The shutdown came a day before a planned quarterly siren test for the Salem/Hope Creek Nuclear Generating Stations, said the The Delaware Emergency Management Agency. Sirens within 10 miles of the facility will blare for about five minutes between 7 and 8 p.m.