Utilities build large thermal electric generating stations next to lakes or rivers. These water sources provide needed cooling for plant systems that generate electricity with turbine generators.
Duke Energy built Oconee Nuclear Station on Lake Keowee, McGuire Nuclear station on Lake Norman and Catawba Nuclear Station on Lake Wylie to ensure a reliable source of cooling water for the closed-loop steam supply systems used in these plant designs. The company places a significant emphasis on nuclear plant safety, dam safety, and the integrity of its lake system.
“Our lakes play a critical role in energy production from our hydro, fossil and nuclear fleet. The safety of these impoundments is critical for our neighbors and the safe operation of our generating stations,” said Brad Keaton, chief dam safety engineer for Duke Energy’s hydro fleet.
For more than 100 years, Duke Energy has designed, built, inspected and safely managed lakes and dams in its service area. While built primarily for generation, these lakes are used for recreation, municipal drinking water and industrial activities.
The Federal Energy Regulatory Commission (FERC) regulates these lakes and requires a stringent dam safety program to ensure the public’s safety.
There are 52 dams operated and maintained in Duke’s hydro fleet. Trained personnel inspect the earthen dams at least every two weeks and the concrete dams at least quarterly. Dam inspections are also performed after a lake receives two inches of rain in a 24-hour period or after a seismic event.
FERC and Duke Energy engineers perform detailed dam inspections annually. Regulators also require dam safety inspections by an approved independent engineering consultant every five years. Divers inspect the underwater portions of spillways and structures at five-year intervals.
Instruments installed in and around the dam structures provide information related to the overall “health” of the dam. These instruments measure critical parameters such as water pressure inside a dam, dam settlement and seepage rate through an earthen dam, which is expected. A report containing the data and engineering assessments is generated annually and reviewed by FERC.
While dams are exceptionally stable structures, Duke Energy has in place detailed emergency action plans and procedures that define our response to a potentially hazardous situation. Appropriate county and state emergency management agencies responsible for notification and evacuation of downstream residents are included in the plan and participate in annual training and drills.
“We are proud of our safety program. We work with our regulators and other industry professionals to continuously improve it. Public safety is of utmost importance to us,” said Keaton.