Three Mile Island History
Three Mile Island Generation Station (TMI) was commissioned in the 1970s to meet the region's growing energy demand with reliable, efficient, carbon-free energy.
Initially a dual-reactor site developed by General Public Utilities (GPU), construction of TMI Unit 1 began in 1968 and construction of Unit 2 began a year later. Unit 1 began producing electricity in 1974 followed by Unit 2, which went into operation in 1978. Unit 2 shutdown permanently in 1979 and will not be reopening.
Following the incident, GPU continued safe operations of Unit 1 until Constellation Energy purchased the unit in 1999. Constellation operated Unit1 for nearly 20 years - shutting it down for economic reasons in 2019. Prior to the closure, the unit’s decades-long safety record was exemplary, and it was among the safest and most reliable power generators in the nation.
During the time Constellation operated TMI, Unit 1 produced enough carbon-free electricity - 800 megawatts - to power the equivalent of 800,000 homes annually. The unit also offset more than 95 million metric tons of carbon emissions over the same period - the equivalent of nearly 20 million cars taken off the road for 1 year.
The unit also supported thousands of jobs across Pennsylvania prior to its 2019 closure, including more than 600 Pennsylvanians employed directly by the plant, 1,500 refueling outage workers who worked at the plant every two years.
The economic and environmental effects of Unit 1’s closure are still being felt. In a February 2024 report, the Joint State Government Commission, a nonpartisan state commission housed within Pennsylvania’s General Assembly, called the 2019 closure of Unit 1 “a preventable and potentially wasteful use of energy infrastructure.” The report also found that Pennsylvania’s air became dirtier when the plant closed, because its clean energy generation was replaced by fossil sources, primarily natural gas.
The commission’s investigation revealed that “The main reason TMI closed was that it could not economically compete in the energy market due to a surplus of cheap natural gas following the Marcellus shale boom. Renewable energy sources were insulated from this market disruption due to State policy choices, but nuclear was not.”
Now, we have an opportunity to correct this mistake. Constellation Energy has announced that it will restart Unit 1 as the Crane Clean Energy Center with operations anticipated to resume in 2028.
This decision represents a pivotal opportunity for Pennsylvania to restore its leadership in clean, reliable nuclear power. Crane will not only bring carbon-free energy back to the region but also deliver significant economic and environmental benefits.
- Reliable Clean Energy: Once operational in 2028, Crane Clean Energy Center will provide 835 megawatts of consistent, carbon-free energy.
- Economic Growth and Job Creation: The center will create 3,400 direct and indirect jobs and contribute approximately $3.6 billion in tax revenue, boosting Pennsylvania’s economy with a projected $16 billion increase to the state’s GDP over its lifespan.
- Environmental Impact: By avoiding 61 million tons of CO₂ emissions over the next 20 years, Crane Clean Energy Center will help clean up Pennsylvania’s air and support broader climate goals, equivalent to removing millions of cars from the road.
- Support for Our Local Communities: The plant’s owner has committed $1 million over five years to philanthropic initiatives supporting workforce development and other regional needs. The company is committed to ensuring that nearby communities directly benefit from the plant’s revival.
The reopening of Crane Clean Energy Center is an investment in Pennsylvania. The facility will not only provide reliable, 24/7 clean energy production but it will also establish economic stability in local communities, support job growth, and foster a cleaner environment.
