AEP’s Cook Unit 2 refueling begins following record performance; $70 million in capital improvement projects to be completed
BRIDGMAN, Mich., Sept. 17, 2007 – American Electric Power’s (AEP:NYSE) Cook Nuclear Plant Unit 2 set several fuel cycle records as the reactor was safely shut down early Saturday to begin a refueling outage. In addition to refueling the reactor and regular outage maintenance and testing work, this outage includes replacing the reactor vessel head and other major component and system improvements. Total project costs will be more than $70 million.
Unit 2 operated continuously since the last refueling in spring of 2006 for a site record run of 497 days. This is known in the industry as a breaker-to-breaker run, as the unit’s circuit breakers remained connected to the transmission grid for the entire 18-month fuel cycle. Projected totals show the unit operated at 100.6 percent capacity factor, a record for Unit 2 and equal to Unit 1’s best performance, and generated 12,903 gigawatthours (GWH) of electricity, just shy of the Cook site record of 13,224 GWH which occurred during a longer fuel cycle.
“These record operating performances and the major capital investments that will be made during this outage demonstrate the power of commitment from AEP and Cook employees,” said Mano K. Nazar, senior vice president and chief nuclear officer. “We have the right daily focus on safety and quality, we’re doing the right work during outages to prepare our units to operate reliably and we are positioned to continue this for many, many years to come.”
More than 1,500 contracted workers will supplement the regular 1,400-person plant staff. Approximately 15,500 maintenance, inspection and equipment modification job activities and 265,000 work-hours are scheduled.
The reactor vessel head replacement has been six years in planning and development. The replacement head incorporates corrosion resistant material that will improve safety and reduce expensive inspection requirements. The Unit 1 reactor head was replaced in 2006.
Other major projects will improve turbine generator reliability and stability, significantly decrease worker radiation exposure in future outages and support the extended operation of the plant. In 2005, the U.S. Nuclear Regulatory Commission approved a 20-year extension of the plant’s operating licenses to 2034 for Unit 1 and 2037 for Unit 2.
“We completed many of these upgrades on Cook Unit 1 last year and have seen the benefits in performance and reliability,” said Nazar. “Completion of this work on Unit 2 truly positions Cook for long-term safe and reliable operation for our customers, employees and shareholders.”
The vessel head is approximately 17 feet in diameter and weighs 100 tons. It was forged in one piece in Japan and shipped to France for fabrication, which entailed complex welding operations and final machining to extremely precise tolerances. The 20-foot housings for the reactor control and shutdown equipment were also installed in France. Forging and fabrication of the new vessel head assembly took more than three years.
The head assembly was transported by ocean vessel to Milwaukee and transferred to a barge that was towed to a temporary dock on the St. Joseph River. Since the container was too large for rail shipment, it was transferred to a heavy haul vehicle and traveled public roads at walking speed for the remaining eight miles to the plant.
Installation of the vessel head will be incorporated into the refueling process. The old head will be temporarily housed at the site before being shipped later for burial at a low-level radioactive waste disposal facility.
Upgrading to a digital turbine control system will improve the reliability and ease of operation of the turbine generator. Another major project is the removal of more than 500 feet of piping and 40 valves that were used to monitor reactor coolant temperature. New in-line temperature detection equipment will be installed. This project was completed on Unit 1 in 2006 and resulted in a 50 percent reduction in radiation exposure for some post-outage jobs and is projected to reduce overall outage occupational radiation exposure by up to 25 percent.
Other modifications and upgrades include: the containment building sump, elimination of the vulnerability of safe operations to single points of equipment failure; replacement of a reactor coolant motor; and required inspections on the unit’s steam generators and one low pressure turbine rotor.
The 1,048 net megawatt (MW) Unit 1 and 1,107 net MW Unit 2 combined produce enough electricity for more than one and one half million average homes.
American Electric Power is one of the largest electric utilities in the United States, delivering electricity to more than 5 million customers in 11 states. AEP ranks among the nation’s largest generators of electricity, owning more than 38,000 megawatts of generating capacity in the U.S. AEP also owns the nation’s largest electricity transmission system, a nearly 39,000-mile network that includes more 765 kilovolt extra-high voltage transmission lines than all other U.S. transmission systems combined. AEP’s transmission system directly or indirectly serves about 10 percent of the electricity demand in the Eastern Interconnection, the interconnected transmission system that covers 38 eastern and central U.S. states and eastern Canada, and approximately 11 percent of the electricity demand in ERCOT, the transmission system that covers much of Texas. AEP’s utility units operate as AEP Ohio, AEP Texas, Appalachian Power (in Virginia and West Virginia), AEP Appalachian Power (in Tennessee), Indiana Michigan Power, Kentucky Power, Public Service Company of Oklahoma, and Southwestern Electric Power Company (in Arkansas, Louisiana and east Texas). AEP’s headquarters are in Columbus, Ohio.