7 November 2007 — American Electric Power’s Cook 1,107 MW nuclear plant Unit 2 completed a refueling outage that included replacing the reactor vessel head and other major component and system improvements. Total project costs of the upgrades were more than $70 million.
The reactor vessel head replacement was six years in planning and development. The replacement head incorporates corrosion resistant material that will improve safety and reduce expensive inspection requirements. The old head will be temporarily housed at the site before being shipped later for burial at a low-level radioactive waste disposal facility. The reactor head on the 1,048 MW Unit 1 was replaced in 2006.
Other major projects will improve turbine generator reliability and stability, decrease worker radiation exposure in future outages and support the plant’s extended operation. 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.
Upgrading to a digital turbine control system will improve the reliability and ease of operation of the turbine generator Additionally, more than 500 feet of piping and 40 valves that were used to monitor reactor coolant temperature were removed and new in-line temperature detection equipment was installed. Both of these projects were completed on Unit 1 in 2006.
Other modifications and upgrades were performed to improve safety and reliability such as expanding the containment building sump and replacing a reactor coolant pump motor.
AEP said that prior to the refueling outage, Unit 2 operated continuously during the entire 18-month fuel cycle for a site record run of 497 days. The unit operated at 100.6 percent capacity factor, a record for Unit 2 and equal to Unit 1’s best performance.