Urgent Alert

Nuclear safety

Be prepared for a nuclear emergency

Emergency preparedness


Diablo Canyon Power Plant is a safe, reliable and clean energy resource for PG&E's customers. Our well-trained and dedicated team of professionals focus every day on the continued safe operation of the facility. While the facility's robust design and built-in redundancies make an emergency event unlikely, it is important to PG&E that we provide this emergency planning information to our neighboring communities so they are prepared if ever needed. This emergency planning information was prepared in conjunction with San Luis Obispo County Office of Emergency Services.


Discover emergency levels


Find out how emergencies are classified

Nuclear power plant emergencies are classified into one of four classifications described below. At each level, DCPP would notify local, state and federal officials. These agencies would take action as outlined in their emergency plans.


  • Unusual Event. A minor, unplanned event has taken place, or a security threat may have occurred. No risk to public health and safety.
  • Alert. A plant safety system has been damaged or may have been damaged, or a security event may have taken place that involves risk to site personnel or damage to site equipment.
  • Site Area Emergency. A radiological release may be expected to occur or has occurred, or a security event may have taken place that damaged plant equipment. The release would not be expected to exceed federal exposure limits beyond the plant site boundary, an area about 1,000 yards from the reactor.
  • General Emergency. A significant release of radioactivity has occurred or may occur, or a security event may have taken place that results in loss of physical control of the plant. Protective actions may be directed in several of the Protective Action Zones.

PG&E notifies local, state, and federal officials during each alert level. The officials take the steps that are included in their emergency plans. Learn more about the NRC.


Understand what each notification means

Find out about notifications of nuclear emergencies through sirens, local radio and television stations, emergency responders and other sources. Learn what each notification means and how to act.

What to do when you hear a siren


San Luis Obispo County's Early Warning System Sirens

The sirens sound to alert you about an emergency taking place in the county. Area residents and visitors can tune in to a local radio or television station for information. The sirens can also mean an emergency is taking place at Diablo Canyon Power Plant (DCPP).


Protective Action Zones (PAZ)

One through 12 have 131 sirens. The locations of these sirens stretch from Cayucos in the North to Nipomo Mesa in the South.

You can also be alerted by sirens and loud speakers used by police and fire agencies when an early warning siren fails to sound.


Follow safety guidelines

In an emergency, you can hear a loud, steady siren that lasts three to five minutes. Use the following steps to stay safe when you hear an early warning siren:


  • Go indoors and tune to a local radio or television station. Stay tuned and listen for important information and instructions.
  • Check in with your neighbors to ensure they are aware of the emergency, if you are able. Inform them of current warnings and related emergency actions.
  • Tune to Marine Channel 16 for emergency information if you’re at sea.
  • Call 805-543-2444 if you urgently need information or assistance during an evacuation. Only call this number if it’s absolutely necessary. The County Office of Emergency Services activates this phone line only when there’s an emergency that affects a large number of people in the area.

Find out more from local radio and television


The Emergency Notification System (ENS) informs you about the nature of the emergency and the steps you must take. All local radio and television stations are part of the ENS. The duty of the ENS stations is to broadcast and repeat official information about major emergencies.

Use reverse 9-1-1 to supplement information


Reverse 9-1-1 is used by public safety organizations to communicate emergency information. The program is designed to inform groups of people in a defined area about emergencies. Reverse 9-1-1 can be used as backup to the warning sirens and ENS.


Landline telephones are automatically included in the Reverse 9-1-1 system. Voice over IP and mobile phones must be registered. Learn more about Reverse 9-1-1 and how to register by viewing the San Luis Obispo County website.


Visit Office of Emergency Services. You can also call 805-781-5011.



important notice icon Note: 9-1-1 is an emergency line for people who need urgent medical, fire or police help. Use the following guidelines before deciding to call 9-1-1.


  • Do not call 9-1-1 to gain information about the emergency. Calling 9-1-1 when there isn’t an emergency ties up the system. The high phone traffic may delay help for someone who needs it.
  • Do not use your telephone unless you must call for help.
  • Do not leave your area unless you’re advised to do so by the ENS.

What to know about an evacuation

Find out what parents with children in school can expect, disability resources and how to make a family disaster plan.

More on nuclear safety

Evacuation tips

Here are some tips in the event of an evacuation.

Shelter in place

Find out what you need to do to if directed by the San Luis Obispo County Office of Emergency Services to remain indoors.

Planning for the agricultural community

Find out about the impact to agriculture and actions that might be required.