May 15 (Reuters) - American Electric Power Company Inc's ( AEP )

Indiana Michigan Power on Wednesday said its 1,194-net

megawatts Cook Nuclear Plant Unit 2 has been manually tripped

offline after a steam leak was discovered on May 14.

The cause of the steam leak is still being determined and

the repair is underway, the company said in a press release.

At 6:00 p.m. on Tuesday, operators began to reduce power to

allow for repair of the steam leak, and removed a turbine from

service to isolate the leak, the company said.

The reactor was removed from service at 4:27 a.m. on

Wednesday, while Unit 1 of the Cook plant remains at 100% power

with no impact to customer service, it added.

The Cook Nuclear plant's Unit 1 primarily services Southwest

Michigan and Unit 2 services Northwest/Central Indiana (as far

south as Fort Wayne, IN), as per the company website.

The company has not provided return to service information,

however, it does not expect the repair to be lengthy.

In late March, the reactor went into its twenty-seventh

refueling outage after running for 12,023 hours during its last

cycle at a capacity factor of 99.4%, generating 14,094,064

megawatt-hours of (net) electricity.

The reactor's operating license is set to expire in December

of 2037, according to the Nuclear Regulatory Commission (NRC).