Nearly 40 years ago, a nuclear meltdown in Pennsylvania changed how power plants in the United States are regulated. The Three Mile Island accident on March 28, 1979, occurred in reactor number 2 of the nuclear generating station in Dauphin County.
It is the worst accident in the history of U.S. nuclear power plants.
Failures in the non-nuclear secondary system, along with a stuck-open pilot-operated relief valve in the primary system, allowed large amounts of nuclear reactor coolant to release. Unknown amounts of radioactive gases and radioactive iodine escaped into the environment.
Cleanup at the plant spanned 14-plus years and cost about $1 billion. The accident triggered instant reaction from other states.
The California Governor’s Office of Emergency Services (Cal OES) joined together with the California Department of Public Health (CDPH) and affected counties to investigate the consequences of a serious nuclear power plant accident. Based on site-specific studies in 1980, Emergency Planning Zones (EPZ) around the plant sites were established in detail and integrated plans were developed.
The Nuclear Power Plant (NPP) Program was developed post-Three Mile Island nuclear meltdown and covers emergency planning issues related to the state’s one operating nuclear power plant – Diablo Canyon Power Plant – and one decommissioning nuclear power plant – San Onofre Nuclear Generating Station (SONGS). The NPP program also continues coordination with two retired nuclear power plants – Humboldt Bay and Rancho Seco.
The Rancho Seco plant in Sacramento County was shut down in 1989 while Humboldt Bay, the first commercial power plant built in the state, has been shut down since the early 1980s.
“The nuclear power preparedness program is the nation’s bedrock for professional emergency management,” said Bill Potter, Senior Emergency Services Coordinator for the Radiological Preparedness Unit at Cal OES. “After the 1979 Three Mile Island nuclear accident, standards were issued by the Nuclear Regulatory Commission (NRC) to prevent an accident from occurring again. Those standards, which our state embraced, were the first standards established that required states with nuclear power plants to have EOCs, communication systems for emergencies, Emergency News Centers (JICs), and organized response agencies to deal with emergencies.”
The NPP program works with federal, state, local and utility officials in emergency planning, training and exercises to test emergency readiness. Together, through these combined preparedness efforts, the State of California provides reasonable assurance that appropriate measures can be taken to protect the health and safety of the public in the event of a radiological emergency at a nuclear power plant.
Legislation mandating the NPP program has been continuous since the Three Mile Island accident, enacted as Government Code and Health and Safety Code sections, called the Radiation Protection Act.
Read here for additional information about the NPP.
Today, Cal OES participated in a five-hour drill at DCPP in San Luis Obispo County. The focus of the drill, which is performed four times per year, is to train staff, evaluate procedures and identify areas that need improvement.
PG&E exercised one of their control room teams and their internal emergency response organization to ensure they are ready to respond to any emergency that could occur at a nuclear power plant. The local and state agencies also participated in the Unified Dose Assessment Center to calculate public protective measures.
About 250 people participated.
“These reoccurring drills are very important to the operating utility at Diablo Canyon Power Plant,” said Potter. “They give each of the operating teams and the response organization the opportunity to respond to an emergency, develop a response, implement the solution, explain to the public what has happened, and to perform an analysis of their performance for the NRC.”
DCPP has two operating units (Units 1 & 2) that are licensed until 2024 and 2025, respectively. The two units produce a total of 18,000 gigawatt hours of electricity annually. DCPP also has an Independent Spent Fuel Storage Installation with spent fuel in dry storage.
“Any items identified as lacking are reported to the NRC and corrective measures are implemented,” Potter said. “The NRC then evaluates the plant’s performance and report and institutes enhanced monitoring of the plant if additional corrective actions are necessary. No other industry is required to perform at this level or to involve the locals and the state in their activities.”
The Nuclear Emergency Response Program (NERP), in the Environmental Management Branch of the Department of Public Health, is responsible for preparing an emergency response plan and training program, and conducting training programs for local, state, and federal officials for implementation in the event of a nuclear power plant accident.
More on NERP can be found here.