Who Owns Seabrook Station?

Seabrook Station's history spans several decades of planning, construction, and operation, reflecting the complex evolution of nuclear power in the United States. The plant was proposed in 1969 by the Public Service Company of New Hampshire (PSNH) as a two-unit nuclear power station to meet growing electricity demand in New England. Construction began in 1976, with the original plan calling for two 1,150-megawatt reactors at a projected cost of approximately $850 million.

The construction of Seabrook Station became one of the most controversial infrastructure projects in New England history. Opposition to the plant began in the 1970s, driven by concerns about nuclear safety, environmental impact on the coastal marine ecosystem, and the plant's proximity to populated areas. The Clamshell Alliance, an anti-nuclear organization formed in 1976, conducted protests and civil disobedience actions at the construction site, including a mass arrest of approximately 1,400 protesters in 1977. The protests at Seabrook became a national symbol of the anti-nuclear movement.

Construction delays and cost overruns plagued the project throughout the 1970s and 1980s. The Three Mile Island accident in 1979 led to increased regulatory scrutiny and additional safety requirements, further delaying construction. The original $850 million budget ballooned to approximately $5.3 billion by the time Unit 1 was completed. The cost overruns contributed to the financial distress of PSNH, which filed for bankruptcy in 1988, becoming the first U.S. utility to file for bankruptcy protection since the Great Depression.

Unit 2 was never completed. Construction on the second reactor was halted in 1986, and the project was eventually abandoned. The partially constructed Unit 2 structure remains on the site but has never been operated.

Seabrook Station Unit 1 received its operating license from the NRC on March 15, 1990, and began commercial operation on June 1, 1990. The reactor is a Westinghouse pressurized water reactor with a rated capacity of approximately 1,250 megawatts, making it one of the largest single-unit nuclear reactors in the United States. The plant uses cooling water from the Atlantic Ocean, with a once-through cooling system that draws seawater and discharges it back at a slightly elevated temperature.

In 2002, NextEra Energy Resources (then known as FPL Energy) acquired a majority ownership stake in Seabrook Station from PSNH (which had been reorganized as part of Northeast Utilities, now Eversource Energy). The acquisition gave NextEra Energy operational control of the plant, while minority ownership stakes were retained by several New England municipal and cooperative utilities.

In 2010, the NRC granted Seabrook Station a 20-year license renewal, extending its operating license from 2030 to 2050. The license renewal process included reviews of the plant's aging management programs, environmental impact, and safety systems. The license renewal was supported by NextEra Energy's investment in plant upgrades and safety improvements.

In 2012, Seabrook Station identified concrete degradation in several plant structures caused by alkali-silica reaction (ASR), a chemical reaction between alkalis in cement and reactive silica in aggregate that can cause concrete cracking and expansion. The NRC issued a confirmatory action letter requiring NextEra Energy to implement a long-term monitoring and mitigation program for ASR-affected structures. The company has implemented a comprehensive ASR management program, including structural evaluations, periodic inspections, and reinforcement of affected areas. The NRC has continued to monitor the ASR issue and has determined that the plant can be operated safely through its license period with the implemented management program.

As of 2026, Seabrook Station continues to operate at high capacity factors, typically exceeding 90 percent, providing approximately 1,250 megawatts of carbon-free electricity to the New England power grid. The plant is a significant contributor to New England's clean energy supply, avoiding approximately 4 million tonnes of CO2 emissions annually that would otherwise be generated by fossil fuel power plants.