EXPLAINER | Three Mile Island
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Three Mile Island

On March 28th, 1979 the Unit 2 reactor at the The Three Mile Island nuclear power plant near Harrisburg partially melted down. It marked the most serious accident in U.S. commercial nuclear power plant operating history.

The aftermath brought about “sweeping changes involving emergency response planning, reactor operator training, human factors engineering, radiation protection, and many other areas of nuclear power plant operations,” writes the Nuclear Regulatory Commission. “A combination of equipment malfunctions, design-related problems and worker errors led to TMI-2’s partial meltdown and very small off-site releases of radioactivity.”

The plant’s still operational Unit 1 reactor is now owned by Exelon, while the mothballed Unit 2 reactor is owned by FirstEnergy.

In May 2017, Exelon announced it would prematurely shut down the plant in September 2019—15 years before its license expires. The nuclear power industry has had a hard time competing economically amid slowing demand for electricity and a glut of cheap natural gas.

Both New York and Illinois recently agreed to give billions in subsidies to the nuclear industry by essentially broadening the definition of clean power. The states created so-called zero emission credits for their nuclear plants. There’s been a years-long lobbying push to do something similar in Pennsylvania.

In March 2019, Rep. Thomas Mehaffie (R- Dauphin County) introduced HB 11 . He wants to prevent the early closure of Three Mile Island as well as FirstEnergy’s Beaver Valley plant near Pittsburgh, which is scheduled for retirement in 2021.

The bill aims to amend Pennsylvania’s Alternative Energy Portfolio Standard, a 2004 law requiring electric utilities to buy parts of their power from certain clean and alternative energy sources, like wind and solar. The bill faces major opposition from across the ideological spectrum.

 

Latest stories


TMI supporters gathered Friday to lament the plant's closure, and the loss of jobs for the area.

With TMI closed, nuclear advocates’ concern shifts to Pa.’s other plants

Those who support nuclear worry that without tax breaks, the plants will be shut out of a competitive energy market
By Katie Meyer

Three Mile Island nuclear power plant, which closed Sept. 20, 2019.

Exelon's Three Mile Island plant is scheduled to prematurely close in September 2019. The company has been lobbying for help from the state to keep it open.

Three Mile Island Unit 2, site of nation’s worst nuclear accident, to be sold, dismantled

EnergySolutions would buy the site from the reactor’s owner, First Energy. The deal does not include the still-operational Unit 1 reactor.

By Marie Cusick

Three Mile Island will close Sept. 30, as nuclear rescue legislation stalls in Harrisburg

The political, historical, and energy landscape of Pennsylvania made nuclear subsidies a tougher sell here, compared to other states.

By Marie Cusick

The Beaver Valley Power Station in Shippingport, Pa. is slated to close in 2021.

Exelon's Three Mile Island plant is scheduled to prematurely close in September 2019. The company has been lobbying for help from the state to keep it open.

Gas, nuclear lobbies butt heads as Senate takes up nuclear-rescue bill

Chamber's first hearing on bill became discussion on fairness of Pennsylvania's energy economy
By Katie Meyer

FILE - In this May 22, 2017 file photo shown is the Three Mile Island nuclear power plant in Middletown, Pa. With nuclear power plant owners seeking a rescue in Pennsylvania, a number of state lawmakers are signaling that they are willing to help, with conditions.  Giving nuclear power plants what opponents call a bailout could mean a politically risky vote to hike electric bills. (AP Photo/Matt Rourke, File)

Political fight begins over bill to rescue Pennsylvania nuclear industry

A House panel heard a litany of arguments for and against a bill that would provide a $500 million annual subsidy to Pennsylvania’s nuclear industry.

By Marie Cusick

FirstEnergy's Beaver Valley Power Station in Shippingport, Pa. is scheduled to retire early, in 2021.

FILE PHOTO: Newsmen and spectators stand in front of the main gate of the Three Mile Island Nuclear Generating Station in Middletown, Penn., April 2, 1979.

‘I remember TMI’: An oral history of the 1979 Three Mile Island accident as told by people who lived nearby

Seven residents tell their stories of uncertainty, confusion, fear and the decision they faced: Stay home amid risk of radiation, or flee.

By Scott Blanchard

In March 1979, Middletown Borough was home to approximately 11,000 residents. It was estimated at that time that 20 percent of the population packed up and temporarily left the area due to the uncertainty of what might transpire at Three Mile Island.

Forty years later, the prospect of a TMI-related evacuation remains daunting

The last several decades have brought more detailed plans and better technology, but the people responsible for TMI disaster prep say there will always be unknowns.
By Katie Meyer
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