By Michael Brooks

Exelon on Wednesday announced it will permanently shut down the nearly 45-year-old Three Mile Island nuclear plant in Londonderry Township, Pa., by Sept. 30.

The company is making good on its May 2017 promise to close the plant absent the Pennsylvania General Assembly providing it subsidies before June 1 of this year, the deadline for purchasing its fuel. Each house of the legislature has been considering its own bill supporting nuclear generation, but the Senate has adjourned until June 3, and the House of Representatives will only meet three more times before the end of the month.

“Although we see strong support in Harrisburg and throughout Pennsylvania to reduce carbon emissions and maintain the environmental and economic benefits provided by nuclear energy, we don’t see a path forward for policy changes before the June 1 fuel purchasing deadline for TMI,” Kathleen Barron, Exelon senior vice president, government and regulatory affairs and public policy, said in a statement.

“While TMI will close in September as planned, the state has eight other zero-carbon nuclear units that provide around-the-clock clean energy, avoiding millions of tons of carbon emissions every year. We will continue to work with the legislature and all stakeholders to enact policies that will secure a clean energy future for all Pennsylvanians,” she said.

But at least one state legislator earlier this week predicted the plant would close regardless of what the General Assembly did. (See Pa. Lawmaker Contends TMI Rescue Unlikely.) The bills being considered would create a third tier in the state’s Alternative Energy Portfolio Standard program, from which suppliers must buy an additional 50% of their power by 2021.

“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,” said Bryan Hanson, Exelon senior vice president and chief nuclear officer. “I want to thank the hundreds of men and women who will continue to safely operate TMI through September.”

Nuclear Energy Institute CEO Maria Korsnick blamed the plant’s closure on “a flawed and distorted energy market that fails to value the attributes of nuclear power.”

“The shutdown will lead to the loss of hundreds of Pennsylvania jobs, more than $1 million in taxes annually to the community and more than 7 million MWh of carbon-free energy,” she said. “It’s in our nation’s best interest for lawmakers both in state capitals and Washington to push for market solutions and polices that value all clean energy sources, or face the economic and environmental consequences for generations to come.”

Three Mile Island is home to two reactors. Exelon has owned Unit 1 since 2000, when the company formed through the merger of Unicom and PECO Energy, the latter of which owned a 50% stake in the unit. The company purchased the other half in 2003 and began operating the plant directly in 2009. The same year, the unit was granted a license extension by the Nuclear Regulatory Commission to April 19, 2034.

Unit 1 was shut down for six years after the partial meltdown of Unit 2 in 1979, the worst commercial nuclear power plant accident in U.S. history. In 1985, over fierce opposition from nearby residents and anti-nuclear activists, NRC voted 4-1 to restart operations.

Exelon plans to begin transitioning staff within six months of the plant’s shutdown, winding down in three phases to 50 full-time employees by 2022. The company will begin to dismantle the plant in 2074.