Refueling outage complete for Cook Nuclear Plant Unit 2

After a refueling outage that spanned 67 days, Indiana Michigan Power’s Cook Nuclear Plant Unit 2 in Bridgman, Michigan, was returned to service on May 7, the company announced.

The extended outage period was planned as the reactor underwent refueling, regular maintenance, and inspection and maintenance of baffle bolts that support internal components of the reactor vessel. The unit was connected to the transmission grid after a valve in the turbine steam system malfunctioned, and it was returned to serve about three hours later.

“The completion of several major projects this outage means the bulk of the Life Cycle Management work for Unit 2 is complete and the unit is well-positioned for long-term viability,” Joel Gebbie, senior vice president and chief nuclear officer at Indiana Michigan Power, said. “The baffle bolt replacement was completed with record-low radiation dose and is now resolved for Unit 2. Now we look forward to another fuel cycle of the extremely high reliability we’ve seen for both Cook units over the past several years.”

Unit 2 operated at 97.9 percent capacity for 423 days in a row prior to the refueling outage. A new 230-ton main generator rotor, three heater drain pumps and new digital reactor control instrumentation were installed in the most recent outage. In the previous outage, four turbine rotors were installed. All original large components of the non-nuclear side of Unit 2 have now been replaced, as well as all six original heat exchangers.