America’s nuclear energy facilities are designed and built to safely withstand a wide variety of natural and other severe events and staffed by highly trained, federally licensed operators with a five-decade history of safe operations in the United States. The operators who staff these facilities are capable of taking the actions necessary to mitigate and control adverse events. An emergency plan provides multiple layers of protection by specifying additional measures that may be taken in the event of a severe accident.
An effective emergency response is the product of mutually supportive planning and preparedness among several parties: companies that operate the facilities; local, state and federal agencies; and private and nonprofit groups that provide emergency services.
Federal law requires nuclear operating companies to develop emergency response plans for their nuclear energy facilities and to ensure that emergency preparedness plans are in place to protect the public. The independent U.S. Nuclear Regulatory Commission approves each facility’s plan, while approval of companion state and local plans is coordinated between the NRC and the Federal Emergency Management Agency (FEMA). The plans must be approved in order for a facility to obtain and retain an operating license from the NRC.
Emergency Planning Zones
Emergency plans continually evolve. Changes have included incorporating lessons learned from the terrorist attacks of Sept. 11, 2001, and other major events. The plans can be implemented during a wide range of severe natural events or security-related events.
The U.S. Nuclear Regulatory Commission and the U.S. Environmental Protection Agency jointly published a report
(NUREG-0396/EPA 520/1-78-106) detailing the planning basis for the development of state and local government radiological emergency response plans for nuclear power plants that found that the most significant impacts of a nuclear energy facility accident would be experienced in the immediate vicinity. At greater distance from the facility—beyond a 10-mile radius—the principal health concern in the event of an accident would be consumption of contaminated water, milk or food.
The task force recommended two planning zones:
a 10-mile emergency planning zone (EPZ) to protect communities near the facility from radiation exposure in the event of an accident
a 50-mile zone within which food products, livestock and water would be monitored to protect the public from radiological exposure through consumption of contaminated foodstuffs.
Within the 10-mile EPZ, the immediate protective actions for the public would include instructions for sheltering in place or evacuation. The pace at which an event may unfold—over several hours or days—would provide sufficient time for sheltering or evacuation, if necessary. Supplemental protective actions within this zone might include the distribution of potassium iodide tablets to protect the thyroid gland from radioactive iodine. Within the 50-mile zone, the federal and state governments may monitor and test all food and water supplies that potentially could become contaminated and, if necessary, remove any that are found to be unsafe from public consumption.
While both zones were established for planning and preparedness purposes, state government response directors have the authority to expand specific protective actions beyond these zones.
Regulations and Guidance
Before the accident at the Three Mile Island (TMI) nuclear energy facility in Pennsylvania in 1979, specific requirements for off-site emergency planning and preparedness had not been established. One of the major lessons learned from TMI was the need for a standard and comprehensive framework for responding to a significant nuclear energy accident. It was recognized that there must be integrated response plans developed by the industry and local, state and federal governmental agencies.
FEMA is the principal agency responsible for directing and assessing off-site emergency preparedness standards. It provides emergency preparedness recommendations and findings to the NRC, which is responsible for overseeing emergency preparedness programs established by the industry and plays a leading role in ensuring continued safe operation of commercial reactors.
Four Emergency Classification Levels
An emergency at a nuclear energy facility is classified at one of four levels as defined by NRC regulations. These four levels are, from least to most serious: unusual event, alert, site area emergency and general emergency.
Coordinated Emergency Planning and Response
An unusual event is an occurrence that has the potential to impact plant safety. No releases of radioactive material requiring off-site response or monitoring are expected unless further degradation of safety systems occurs. Nuclear energy facilities declared 31 unusual events in 2013.
An alert indicates that there has been a substantial decrease in the level of plant safety. If there is any release of radioactive material, the off-site doses would be limited to small fractions of the EPA public exposure levels. Three alerts were declared in 2013.
During a site area emergency, major failures of plant functions needed for protection of the public have occurred or are likely to occur. Should there be a radiological release, the off-site doses are not expected to exceed EPA protective action guideline exposure levels except near the site boundary. There has only been one site area emergency, which occurred in 2006.
In a general emergency, there is substantial damage to the nuclear fuel, with a potential for loss of containment integrity and a radiation release. Any radiological release could exceed EPA public exposure levels off site for more than the immediate plant area. There have been no general emergencies since the criteria were established after the accident at TMI.
Emergency preparedness programs for nuclear energy facilities are highly coordinated and tested, involving the operating companies and local, state and federal agencies. Each entity has specific responsibilities.
Companies that operate the reactors are committed to operating the facility safely and having an on-site emergency plan and trained personnel capable of implementing diverse and redundant methods to keep the reactor in a safe condition. During an event, the company’s trained personnel will immediately implement procedures to respond, classify the emergency, activate the nuclear energy facility’s emergency response organization, and notify state, local and federal authorities. The state and local authorities will make the determination of what actions, if any, should be directed to the public. The company also continuously monitors radiation levels and provides this and updated technical information to off-site authorities throughout the event.
The NRC is responsible for ensuring that the commercial use of nuclear materials is conducted safely. As part of the regulatory process, four regional offices conduct inspections, provide enforcement and review emergency response programs. NRC resident inspectors are on duty at each nuclear facility and have unfettered access to the facility. The NRC is the lead agency for coordinating federal actions in response to an accident at a commercial nuclear energy facility. The agency maintains a headquarters incident response center, where operations officers are on duty around the clock.
FEMA is responsible for setting standards for off-site emergency preparedness programs and assessing their effectiveness. FEMA’s Radiological Emergency Preparedness Program provides assistance to state and local governments in developing emergency plans for nuclear energy facilities and coordinating with other federal agencies to carry out federal planning and response functions.
As part of emergency preparedness for nuclear energy facilities, state and local agencies develop detailed evacuation plans for populations within the 10-mile EPZ. These plans typically include several scenarios to reflect such variables as time of day, season, weather conditions and population group (general, transient and special facilities, such as schools and hospitals). The EPZ is subdivided into emergency response planning areas, and population estimates are provided for each area. These plans and evacuation time estimates
are updated periodically to reflect population shifts and changes in the transportation network.
Should officials decide to evacuate some areas near the facility, they will map the evacuation areas based on weather conditions and wind direction.
“Evacuation does not always call for completely emptying the 10-mile zone around a nuclear power plant. In most cases, the release of radioactive material from a plant during a major incident would move with the wind, not in all directions surrounding the plant,” according to the NRC. “The release also would … become less concentrated as it travels away from a plant.”
Responder Training, Practice and Evaluation
Plant personnel assigned to the facility’s emergency response team must participate in initial and periodic requalification training. Energy companies also offer specialized training to off-site personnel who may be first-responders to a plant emergency (for example, local ambulance or firefighting crews). Off-site agencies also conduct training.
All nuclear energy facilities must participate in federally evaluated, full-scale emergency response exercises every two years. The NRC also requires nuclear plants to conduct training drills in alternate years to test and maintain their emergency response capabilities. State and local emergency management officials participate in these drills.
Following each exercise or drill, the company and participating federal, state and local emergency response personnel conduct an in-depth critique of their performance to identify areas needing improvements. Significant issues are placed in the company’s corrective action tracking system to ensure proper evaluation and resolution, which is subject to inspection by the NRC.
Experience With Emergency Plans
Emergency plans for U.S. nuclear energy facilities have been activated in response to relatively minor events. More frequently, however, local officials have used emergency response plans developed in conjunction with the nuclear industry to respond effectively to natural disasters. In 2007, wildfires ravaged 380,000 acres of California and prompted the evacuation of 300,000 people. During the evacuation of areas around the San Onofre nuclear energy facility (which has since shut down permanently), state and local emergency responders drew upon the relationships and communications links established through their experience with nuclear energy facility emergency preparedness.
Industry Committed to Preparedness
Emergency preparedness at U.S. nuclear energy facilities is an integral part of daily operations. The industry demonstrates its continuing commitment to emergency preparedness by constantly exercising emergency plans and procedures, upgrading emergency response facilities and equipment, and by conducting responder training and drill programs to maintain proficiency. Each company works with its state and local public safety partners to ensure that the response capability is comprehensive and well integrated to ensure public health and safety.