Revised and reposted from June 2014
Note: Outdoor warning sirens will be tested on Wednesday, April 8, 2020 as part of regularly scheduled maintenance. No action is required by residents.
Emergency planning is a top priority in the nuclear industry. Being prepared for any event at a site ensures the safety of the public and nuclear employees. While most believe emergency planning and preparedness was born in 1979, it continues to evolve within the nuclear industry, and it is a collaborative effort between utilities, counties, states and federal agencies.
An important part of emergency preparedness in Duke Energy’s service area includes outdoor warning sirens, which are owned and installed by Duke Energy around its nuclear stations. They are pole-mounted safety sirens and extend out for a 10-mile radius in the communities surrounding the plants. The sirens are managed by the local county emergency preparedness division and can be sounded for any type of emergency where public action is needed such as a tornadoes, hurricanes or flooding.
In the unlikely event of an emergency at a nuclear plant, plant officials notify local emergency officials, including the county, and the outdoor warning sirens located in the 10-mile emergency planning zone (EPZ) can be activated to alert the public to the situation. The outdoor warning sirens sound for three-minute intervals if there is an emergency that could affect the public. If there were an emergency at a nuclear station, Duke Energy would notify county, state and federal officials who would make the decision regarding sounding the sirens and any public protective actions. The outdoor warning sirens are part of the Emergency Alert System (EAS). Hearing a siren does not mean individuals should evacuate. The siren warning system is to prompt individuals to go inside and listen to their local radio or television station for an emergency alert system message.
Outdoor warning sirens are activated from a radio-controlled system and are regularly tested to make sure they work properly. Residents within the 10-mile EPZ are provided information on siren test dates and times. There are several types of siren tests performed at different times – some weekly, monthly or quarterly. “Silent tests” confirm the radio feedback system receives a signal. A “low growl” test verifies proper operations as well as radio feedback signal receipt, and results in a momentary sound, or growl, of the siren. A full volume test results in the sirens sounding for several minutes. If sirens are heard and residents are not sure if it is a test of the system or an emergency, they should tune to a local radio station or television station. If there is an emergency, the stations will interrupt regular broadcasting to provide information to the public.
All nuclear facilities have multiple backup safety systems to ensure safe operations. Additionally, emergency exercises are conducted with plant personnel, state, county and federal agencies to ensure emergency plans are effective and participants are well trained.
Outdoor warning sirens provide another layer of protection that can be utilized to ensure public health and safety during any type of emergency at a nuclear site or in the community.