Indian Point's Unit 2 Back in Service After Shutdown
January 13, 2010
Indian Point's unit 2 nuclear power plant automatically shut down Monday afternoon due to a problem with its main electrical generator. The generator is located on the non-radiological part of the plant. Plant equipment performed as designed during the shutdown.
Initial review indicates the generator likely shut down automatically as a result of a maintenance procedure being performed on the generator's rectifier bank system.
There are four banks of rectifiers inside the unit 2 generator. The rectifier system provides electrical current to create an electromagnetic field inside the generator. A rotor spinning inside this field generates electricity.
Maintenance was being performed over the last several days on a small leak of cooling water inside one bank of rectifiers. It is believed that a switch to isolate one bank of rectifiers from the other three didn't fully disengage during maintenance activities. This ultimately resulted in a component failure within that bank of rectifiers, which ultimately caused the generator to shut down automatically.
Workers have completed repairs and unit 2 connected to the grid generating electricity about 9:00 p.m. yesterday. The plant is currently at 41% power and ascending.
Unit 2 had been operating for 66 continuous days prior to Monday's shutdown.