The nuclear power industry uses radioactive materials, such as uranium, as fuel for the generation of electricity. Before operation of the nuclear power plants in California, the U.S. Nuclear Regulatory Commission (NRC) conducted lengthy plant design review, location selection, operations and plant safety features in coordination with other federal, state and regional authorities to ensure that comprehensive safety standards were met.
Nuclear Power Plants in California
There are two operating nuclear power plant sites in California:
Diablo Canyon (operated by Pacific Gas & Electric) in San Luis Obispo County has two operating units.
San Onofre Nuclear Generating Station (operated by Southern California Edison) in San Diego County has two operating units. A third unit at San Onofre is in a "safe storage" mode (this means that the nuclear fuel has been removed and safely stored).
There are two retired nuclear power plants in California:
Humboldt Bay station near Eureka (owned by Pacific Gas & Electric). Humboldt Bay has been shut down since the early 1980s. Rancho Seco power plant near Sacramento (owned by the Sacramento Municipal Utility District). The Rancho Seco plant in Sacramento County was shut down in 1989 and the entire plant is in a "safe storage" mode.
Nuclear Power Plant Safeguards
Triple-safeguard features prevent the release of radiation:
1. Metal tubes or rods, which contain the fuel pellets, act as the first barrier.
2. Next, the fuel rods are contained in the reactor vessel within 8-inch thick steel walls.
3. Finally, an airtight containment building is constructed of metal and reinforced concrete walls, totaling more than four-feet thick.
Control and safety systems within the plant are designed to overlap for safety. Automatic systems have the ability to shut down the reactors within seconds if monitoring devices detect unusual conditions, such as an excessive heat build up. Should any individual safety component fail there are back-up systems that take over immediately.
The NRC has resident inspectors assigned to each plant site. The inspectors oversee plant operations and ensure compliance with regulations governing operational and occupational safety. There are automatic communications systems that contact the State Warning Center in Sacramento if certain conditions, such as an earthquake or certain plant conditions, occur. The State Warning Center will be able to contact key personnel needed in an emergency.
Nuclear Power Plant Emergency Preparedness
Planning, preparing, and training for nuclear power plant emergencies are also part of the safeguards. Federal, state, and local emergency management agencies work with the utilities to ensure that nuclear power plants are safe and that each agency and utility has an effective emergency plan describing the actions to be taken in response to an emergency. Residents and businesses near a nuclear power plant should prepare a disaster plan for all emergencies including nuclear power plant
emergencies and should become familiar with the emergency preparedness information. You can find information regarding nuclear power plant safety issues in general, at the federal NRC (Nuclear Regulatory Commission) website at: www.nrc.gov. The NRC has primary jurisdiction over nuclear facilities in the United States and it works closely with state and local emergency agencies.
A series of zones has been established around each nuclear power plant to clearly identify the required activities in the event of an accident. Although three specific zones are identified, efforts to protect public health and safety and the environment are made without regard to whether particular areas are inside or outside of these zones.
The Emergency Planning Zone is an approximate 10-mile radius around the plants. Plans for this zone are in place to protect people, property, and the environment from the effects of exposure to a radioactively contaminated plume.
The Ingestion Pathway Zone covers an approximate 50-mile radius around the plant. In this zone, plans are in place to mitigate the effects on a radioactive contamination to agriculture, and food processing and distribution.
Within Public Education Zones, including areas approximately 35 miles from the plants, educational materials are distributed to inform the public about nuclear power plant operations, what to expect in the event of an accident, and what plans are in place for public protection. The utilities that operate the power plants are required to publish and disseminate information for residents and transient populations.
If you live in the Emergency Planning Zone, you will receive materials annually about what to do if there is a radiological emergency at the nuclear power plant near you. These instructional materials are also found in the phone books in communities near a nuclear power plant. These materials contain educational information on radiation, instructions for evacuation and sheltering, special arrangements for the handicapped, and contacts for additional information.
Read the materials.
Keep them in a readily available location.
For more complete information about what to do in a nuclear power plant emergency, see the What to do in the Event of a Radiological Emergency section of this website.
During an emergency, public information will be provided using Emergency Alert System (EAS). Messages that are broadcast on radio and television stations and supplemented by media releases authorized by local and state government officials. Residents in the Emergency Planning Zone will be alerted to tune into a station carrying the EAS messages by sirens that surround each nuclear power plant.
The EAS messages and media releases will include information about the emergency, as well as detailed information on reception center locations, evacuation or sheltering instructions, and other useful information such as whether or not the County Health Officers have authorized people to take potassium iodide (KI).
More information about KI can be found on the Potassium Iodide (KI) and the Useful Links sections of this web site. In 2003, there was a one-time-only no-cost distribution of KI to people within the Emergency Planning Zone around the nuclear power plants at San Onofre and Diablo Canyon. More Information About Nuclear Power in California
San Onofre Nuclear Generating Station (SONGS) – Additional Information
Additional Nuclear Power Plant Information:
California Department of Public Health:
Nuclear Regulatory Commission:
Federal Emergency Management Agency: