BRIDGMAN, Mich., October 3, 2016 – Indiana Michigan Power’s Cook Nuclear Plant Unit 2 will begin its twenty-second refueling outage Tuesday at midnight. Power was reduced to 50 percent Sunday evening for equipment testing prior to the outage. During the 18-month fuel cycle, the unit is projected to have generated 13.5 million megawatthours of electricity at a capacity factor of 99.4 percent. Unit 2 has operated at effective full power for the last five fuel cycles dating back to May of 2009. Cook Unit 1 remains at 100 percent power.
In addition to refueling the reactor and performing regular maintenance and testing work, the outage will be extended due to the replacement of the main turbine and the inspection and replacement of baffle bolts, which support internal components of the reactor vessel. Specific outage duration is considered proprietary information, but the outage is expected to be completed in the fourth quarter of this year.
Replacement of the high-pressure turbine and all three low-pressure turbines is the largest of Cook’s Life Cycle Management (LCM) projects. The $250 million turbine replacement has been in the planning for more than five years and it was known that it would extend this outage. LCM includes 117 upgrade and replacement projects as part of the 20-year operating license extension granted by the Nuclear Regulatory Commission in 2005.
AEP will accelerate baffle bolt inspections previously planned for 2019 based on industry initiatives that commenced following the discovery of degraded baffle bolts at two plants this spring. Any degraded bolts will be replaced and it’s likely that additional bolts will be proactively replaced this outage.
“Extension of this outage is the right thing for us to do at this time.” said Joel Gebbie, AEP Senior Vice President and Chief Nuclear Officer. “The new turbine will provide reliable generation for decades to come, and taking action now on the baffle bolt issue will begin the overall resolution of this important matter.”
The baffle bolts hold the baffle plates in place which direct water flow through the fuel assemblies in the reactor. Similar bolt failures have occurred previously in the industry and specialized repair tools and existing safety analyses are used to resolve the issue. The identified causes of the failed bolts were considered in the replacement bolt design and repair. Additional baffle bolt inspections and replacements, and a potential design change to minimize stress on baffle bolts, may also take place in subsequent outages for both Cook units.
Another of the LCM projects this outage is replacement of two 40-ton safety-related heat exchangers. Other major projects include emergency power cable and battery replacements, pump and valve overhauls and improvements to the nuclear fuel handling equipment
About 2,500 contracted workers will supplement the regular 1,200-person plant staff leading up to and during the outage. About 500 of those workers will be dedicated to the turbine replacements alone. More than 15,500 maintenance, inspection and equipment modification job activities totaling almost 400,000 work-hours are scheduled for two daily 12-hour work shifts.
At full capacity, the 1,030-net MW Unit 1 and 1,077-net MW Unit 2 combined produce enough electricity for more than one and one half million average homes.
Indiana Michigan Power is a wholly owned subsidiary of American Electric Power (NYSE:AEP).