So, you’re looking at the skyline in Pennsylvania and wondering about those giant cooling towers. It’s a fair question. Pennsylvania has always been a heavy hitter in the power game, and honestly, the answer to how many nuclear plants in PA is a bit of a moving target right now.
If you just want the quick headcount: Pennsylvania has 4 operating nuclear power stations. But that number doesn't tell the whole story. Not even close. If you had asked this a few years ago, the answer was five. If you ask in another year or two, it might be back to five again. There is a massive, multi-billion-dollar "nuclear renaissance" happening right in our backyard, fueled by everything from climate goals to the sudden, insatiable hunger of AI data centers.
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The Active Fleet: Who is Still Running?
As of early 2026, the four sites keeping the lights on are Beaver Valley, Limerick, Peach Bottom, and Susquehanna. These aren't just small-town utilities. We're talking about massive industrial hubs that provide roughly a third of the state’s electricity.
Beaver Valley Power Station
Located out west in Shippingport—about 30 miles from Pittsburgh—Beaver Valley is a two-unit site. For a while there, things looked grim. Vistra, the owner, was actually planning to shut it down in 2021 because it was getting hammered by cheap natural gas prices.
That changed. Fast.
Just this month, in January 2026, Vistra and Meta (the Facebook people) announced a massive deal. Meta is basically funding an "uprate"—which is just a fancy industry word for a power boost—to add about 140 megawatts of new capacity to Beaver Valley. They need the carbon-free juice for their AI models, and Pennsylvania’s nuclear fleet is the only thing big enough to provide it.
Limerick Generating Station
If you’ve driven near Philadelphia, you’ve seen Limerick. It’s a beast. Located in Montgomery County, it has two reactors that can power nearly 2 million homes.
Limerick is currently making history for a different reason. The NRC just gave the green light for a $167 million digital overhaul. Believe it or not, most nuclear plants have been running on old-school analog dials and switches for decades. Limerick is the first in the nation to get a full-scale digital "brain transplant" while still operating. It's basically like swapping a 1980s dashboard for a Tesla screen while driving down the highway.
Peach Bottom Atomic Power Station
Sitting right on the Susquehanna River in York County, Peach Bottom is one of the oldest and most reliable workhorses in the country. It’s co-owned by Constellation and PSEG.
What’s wild about Peach Bottom is its longevity. Most of these plants were originally licensed for 40 years. Peach Bottom is already cleared to run for 80. Think about that—a machine built in the 70s that will still be humming along in the 2050s.
Susquehanna Steam Electric Station
Up in Luzerne County, Talen Energy runs the Susquehanna plant. It’s the sixth-largest nuclear facility in the United States. Like Beaver Valley, Susquehanna is caught up in the data center craze. There’s a massive Amazon (AWS) data center campus being built right next to the plant so they can plug directly into the source.
The "Zombie" Plant: Three Mile Island’s Big Comeback
You can't talk about how many nuclear plants in PA without mentioning the most famous one of all: Three Mile Island (TMI).
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For years, the answer was "TMI is dead." Unit 2 had the famous partial meltdown in 1979 and is currently being dismantled. Unit 1—the one that didn't have the accident—was shut down in 2019 because it wasn't making enough money.
But here’s the twist.
Constellation Energy renamed Unit 1 the Crane Clean Energy Center and is currently in the middle of a massive restart project. Microsoft signed a 20-year deal to buy every single megawatt the plant produces. They are aiming to have it back online by 2027.
So, while we officially have four operating plants today, the skeleton of a fifth is currently being brought back to life. It’s the first time in American history a decommissioned nuclear plant has been pulled out of retirement like this.
Why the Number Matters
Pennsylvania is the second-largest producer of nuclear power in the U.S., trailing only Illinois. That’s a huge deal for the local economy. We're talking about roughly 5,000 high-paying jobs and billions of dollars in tax revenue.
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The reason everyone is obsessed with the count right now is "grid reliability." As coal plants shut down across the state, the grid is getting squeezed. Nuclear is the only "baseload" source—meaning it runs 24/7 regardless of the weather—that doesn't pump out carbon.
The Challenges
It isn't all sunshine and rainbows. These plants are incredibly expensive to maintain. The digital upgrades at Limerick and the restart at TMI cost billions. There is also the persistent question of what to do with the spent fuel. Right now, it just sits on-site in giant concrete "dry casks."
Also, while the state government—led by Governor Shapiro—has been very supportive, there is always pushback regarding safety and the environmental impact of the cooling water taken from rivers like the Schuylkill and the Susquehanna.
What’s Next for PA Nuclear?
If you're keeping score, here is what to watch for over the next 12 to 18 months:
- TMI Unit 1 Progress: Watch for the NRC to finalize the restart permits for the Crane Clean Energy Center.
- The "Uprates": Look for construction to start at Beaver Valley to increase its power output for Meta.
- Small Modular Reactors (SMRs): There’s a lot of talk about building smaller, cheaper reactors at old coal sites in PA. No shovels are in the ground yet, but the conversations are getting serious.
Basically, Pennsylvania has doubled down on nuclear. While we have four plants today, the infrastructure is expanding through technology and restarts rather than building massive new domes from scratch.
Next Steps for You:
If you live near one of these facilities, you can actually track their daily power output through the NRC’s Power Reactor Status Reports. It’s updated every morning and shows exactly what percentage of power each unit is putting out. It's a great way to see if a plant is down for "refueling" (which happens every 18–24 months) or if it's running at a full 100% capacity.