Last Reactor at Three Mile Island Will Shut by End of September

The remaining nuclear reactor at the Three Mile Island Generating Station (TMI) in Pennsylvania will shut down by the end of September. Exelon made that official May 8, setting the closing date for Unit 1 at the financially struggling plant that it first announced it would shutter two years ago.

Exelon in 2017 said the plant, best known as the site of an industry-changing nuclear accident in 1979, would be closed unless state lawmakers stepped in to provide financial relief to keep the 819-MW Unit 1 reactor online. Exelon then changed course, campaigning to save the plant and seeking a state subsidy to keep it operating, saying TMI should be compensated for producing carbon-free power.

Subsidies for nuclear power have been adopted in other states, including New York, New Jersey, Illinois, and Connecticut. In Pennsylvania, though, the state’s natural gas industry—Pennsylvania sits in the heart of the Marcellus Shale—waged a strong lobbying effort against help for the nuclear industry. That effort was helped by opposition to subsidies from consumer advocates and industrial gas users.

“With only three legislative session days remaining in May and no action taken to advance House Bill 11 or Senate Bill 510, it is clear a state policy solution will not be enacted before June 1,” Exelon said in a press release Wednesday that referenced the proposed nuclear subsidy bills.

Exelon had said it needed to decide TMI’s fate by June 1, since it would need to purchase fuel for the plant for its next operating cycle.

“Today is a difficult day for our employees, who were hopeful that state policymakers would support valuing carbon-free nuclear energy the same way they value other forms of clean energy in time to save TMI from a premature closure,” Bryan Hanson, Exelon senior vice president and chief nuclear officer, said in a statement Wednesday.

Lawmakers Reject ‘Rescue Bill’

Exelon said its decision to retire the plant came when it was clear a proposed $500 million “nuclear rescue” bill would not pass the legislature. TMI Unit 1 was licensed to operate for another 15 years.

State Sen. Ryan Aument, a Republican from Lancaster who is a co-chair of the state’s Nuclear Caucus and co-sponsor of the nuclear bill, in a statement said, “Unfortunately, it is clear at this point in time that there is not sufficient support to advance a proposal in time to preserve TMI.”

The plant near Harrisburg employs about 700 workers.

John Levengood, president of the Electricians Local 777 union that represents about 280 workers at the plant, told The Inquirer newspaper: “This is a tough blow, devastating. It’s a sad day for the state of Pennsylvania, honestly. Despicable. It didn’t even come up for a vote.”

Exelon said workers at TMI will be offered positions elsewhere in the company, though that would require them to relocate. The plant also has employed thousands of contract workers during its maintenance and refueling outages.

1979 Accident Changed U.S. Nuclear Industry

TMI is best known for the accident that occurred on March 28, 1979. Unit 2 at the plant suffered a partial meltdown that day after a pump stopped sending water to cool the steam generators that removed heat from the reactor core. The accident was the start of a backlash against the U.S. nuclear industry, causing many new reactor projects to be scrapped.

No new reactors broke ground in the U.S. from 1977 until 2013, when construction began on a two-unit expansion of the Vogtle plant in Georgia, which could begin commercial operation in 2021. The only new unit to come online in the past 20 years is Watts Bar 2 near Spring City, Tennessee, named POWER’s Plant of the Year in 2018. Unit 1 at Watts Bar came online in 1996; construction on Unit 2 was halted in 1985. The Tennessee Valley Authority (TVA) in 2007 said it would resume Unit 2 construction, eventually bringing the reactor online in 2016.

Supporters of nuclear power in Pennsylvania have said they will continue to seek subsidies in an effort to keep the state’s other four nuclear plants operating.

Pennsylvania Gov. Tom Wolf, a Democrat, in late April announced a plan to reduce the state’s greenhouse gas emissions. Wolf said he supports policies to keep the state’s nuclear reactors operating, noting the units produce carbon-free power.

Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).