Visit the Three Mile Island Nuclear Accident Site in Pennsylvania!

Three Mile Island Accident Site Reactor #2 silos

☢️ The 2 water cooling silos on the left fed Nuclear Reactor #2, seen to the right with the domed top.  Radiation contamination spewed out with the steam from these silos during the 1979 accident.  This nuclear reactor experienced a partial core meltdown, the most dreaded disaster a nuclear facility can have.  

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Perfect Storm- Era of Crises & Fear

In 1979, Three Mile Island (TMI) was the site of the worst nuclear power plant accident in US history, still to this day.  Two million people were exposed to radiation contamination.  The uranium core experienced a (partial) meltdown, the worst possible scenario.  America held her breath as Pennsylvanians went through 5 confusing days of terror.  The Three Mile Island Nuclear Accident Site captivated the attention of the nation & world.  Only 10 miles from the state capital of Harrisburg, in the small town of Middletown, was the start of a nightmare that everyone feared. 


The United States was gripped in the Cold War with the Soviet Union (Russia, today) where both sides feared a nuclear attack that could lead to the end of the world.  Kids, like Bill and I, practiced ‘Duck & Cover’ drills at school in case of nuclear attack.  Some bought fallout shelters and buried them in their backyards like tornado shelters.  People had been living 30 years with this continuous nuclear threat & fear.  The WWII atomic bombings of Hiroshima & Nagasaki happened just over 30 years before.  Hollywood pumped out movies that played out nuclear war fears.  The images and dangers of a nuclear explosion were fresh in the public’s mind.  On the other hand, we were stuck in the Energy Crisis of the 1970s where an oil shortage created sky-high prices (around $3.50/ gallon in today’s dollars) for inefficient, gas guzzling cars.  People stood in gas lines for hours, until the station sold out of fuel.  We worried how we would heat our homes in winter.  Nuclear power was seen as the New Hope and a positive use for immensely powerful atomic energy.  Nuclear power plants were a relatively new technology and had only been around since the mid 1950s.  We had only landed a man on the moon less than 10 years before.  Modern advances in Science and Technology were fast-moving and not widely understood by the public, at the time.   


To top off this perfect storm, 12 days before the nuclear accident at Three Mile Island in Pennsylvania, the movie ‘The China Syndrome‘ was released.  Starring a young Michael Douglas, Jack Lemmon & Jane Fonda, it was the 1st movie to address the dangers of a nuclear power plant disaster.  The term ‘China Syndrome’ is a, perhaps, exaggerated theory that the meltdown of a nuclear core would be an unstoppable, radioactive magma that would burn right through the earth, all the way to China.  In a chilling, foreshadowing coincidence, the film’s nuclear engineer says that an accident would ‘render an area the size of Pennsylvania permanently uninhabitable.’  Less than 2 weeks later, Pennsylvania would be living out the nightmare of that line.  

Three Mile Island electricity

The remaining TMI Nuclear Reactor #1 generated enough power to continuously fuel 800,000 homes with clean energy.  This field of transmission towers is across the street, near the Training building where the crisis press conferences took place.

Through a series of mishaps, compounded by operator error and flaws in the design & procedures, TMI would experience the start of the worst case scenario for a nuclear plant disaster.  The nuclear core containing Uranium 235 is highly radioactive, highly unstable, with crazy amounts of energy.  They control (& aid) the nuclear fission process that creates the heat and steam they need to produce electricity by keeping that nuclear reactor core cool.  Through missteps and mistakes, they would unknowingly starve the core of cooling water and fail to remove the heat.  That would lead to a dangerous buildup of heat and pressure, and a radiation contamination leak to the surrounding community.  It would also cause a meltdown of 1/2 of the nuclear core with temps of over 5,000º F.  This partial meltdown came dangerously close to melting through the containment (8 inches of steel & 4 feet of concrete) and burning into the water and ground.  Contaminating them permanently.  The start of the China Syndrome catastrophe that nuclear physicists fear.  For more info and explanation of the accident and those frantic 5 days of terror (and our visit), watch my Three Mile Island travel video.

The surrounding communities learned of ‘an incident’ at the TMI plant 4 1/2 hours later, but were told it was under control and of no danger to the public.  They went to school, work and around town.  They didn’t learn they were living under a radiation leak for 2 days, while still stuck in the middle of the lingering crisis.  A limited evacuation order was issued, but people panicked and 144,000 fled, some never to return.  A 3rd crisis was realized when experts found a hydrogen bubble building in the core.  The public’s understanding of a hydrogen explosion was of experimental hydrogen (fusion) bombs.  Kind of the big daddy of bombs, 1,000 times more powerful than the terrifying force of atomic bombs.  A hydrogen explosion in the core would blow uranium and radioactive bits into the air and land for miles, as happened to some degree in the Chernobyl & Fukushima disasters.  Many would be killed or die from radiation poisoning, and parts of Pennsylvania would become uninhabitable.  Concerned US President Jimmy Carter & 1st Lady, Rosalynn, visited to calm the growing panic.  After 5 long, terrifying days, experts realized they had time to vent the hydrogen and the crisis was over.  Most people returned within 3 weeks.  Some never at all.  Those who came back lived in the shadow of the Three Mile Island Nuclear Power Plant wondering, ‘will it happen, again?’ 


Many studies were conducted, including ones from colleges and independent groups not tied to a government agency.  All were looking for evidence, but no significant dangers or illnesses were ever found due to the very low levels and type of radiation contamination released, and the very fast decay rate of those.  Only small trace amounts of radiation have been shown to have leaked, only radioactive iodine, not the scarier possibilities, and it dissipated very quickly.  The highest dosage was equal to 1/6 of what you would get having a chest xray.  We receive small doses of background radiation every day from our granite countertops, to sunlight & cosmic radiation, radon or other sources in soil and drinking water or absorbed by plants we ingest, and medical testing.  However when someone is diagnosed with cancer or an illness in the TMI area, some still wonder if it’s the accident’s fault.  You can’t blame them.  The accident was traumatic and the jumble of conflicting info in a pre-digital world created a lot of distrust.        

Three Mile Island Nuclear Power plant

TMI Nuclear Reactor 2 on the left was shut down after the accident.  Reactor 1 operated for years before Reactor 2 began and functioned for over 40 years after, with no problem.  Steam like you see from Reactor 1, here, poured out of Reactor 2 in 1979 with radioactive iodine 131 gases, unknown for 2 days.  

Visiting The Three Mile Island Nuclear Accident Site, Today:

What’s left to see-

We couldn’t go through Pennsylvania without seeing the site of the infamous nuclear event.  If you lived during the Cold War, especially as a kid, it had a big effect and reminds you of fear and nightmares.  Going through the small town of Middletown, Pennsylvania, down the main street that leads past the plant, you’ll recognize it from news footage.  I imagined the people going about their day in town for 2 days before learning of the radiation leak.  Of 144,000 fleeing when the governor declared a state of emergency and gave a limited evacuation order.  I thought of the people who took their money from the bank, here,  before they fled.  Of the ominous fear for those who stayed.  The unease for 40 more years when they returned. 


Just past town, we passed the bridge that takes you out to the island.  You’ll recognize it from news footage when US President Jimmy Carter crossed it for his nerve-wracking visit of the plant.  (Jimmy Carter has an interesting nuclear past that had him urinating radioactive urine for 6 months! ☢️ I tell you about it & share other pix and details in my Three Mile Island video).  Nice, little houses and small farm fields sit right across the road from Three Mile Island.  Through the breaks in trees, we saw the iconic nuclear cooling water silos out on the river island.  In 2014, when we were there, the plant’s 1st reactor was still operating.  Its silos still poured out steam while the 2nd reactor sat contaminated & still next to it.  35 years before our visit, the silos from the 2nd reactor spewed radiation contaminated steam & gasses for days.  It was an eerie feeling knowing that this steam could be doing the same thing that day and I wouldn’t have known.  Between the 2 sets of cooling silos are the nuclear reactors, column-shaped with a dome roof and their containment buildings.  Nuclear Reactor #2 from the accident is on the left and the Nuclear Reactor #1 on the right.  Down the road, on the left was the former Visitor Center and Viewing Station that you can recognize from the tense news conferences during the crisis.  In 2014, it was a TMI plant training center.  Nearby is the Historic Landmark Marker about the disaster.  

Three Mile Island nuclear reactors

The 2 Nuclear Reactors.  #2 with the accident on left and #1 on right.  It took 14 years and 1 billion dollars to clean-up #2, some which can’t be completed until 2041 due to radioactive levels within the containment area still being unsafe for humans.  Chilling to think about and see.    

Is the Three Mile Island Nuclear Accident Site Safe Today?

It is completely safe to visit (or live) in the area, today.  In 1979, the plant leaked radioactive iodine 131 gases.  The half life of iodine 131, the time it takes to decay and reduce to half of the radiation levels, is 8 days at full strength exposure.  This leakage was diluted into the atmosphere with air and water.  In 16 days, it would have been at levels of a 1/4 of the original, which were very minimal to start with.  Even the 50 some employees working openly, on site at the plant for hours before knowledge of the leak did not receive enough contamination to suffer radiation poisoning.  Within just a few weeks, none was detectable at all, so any radioactive contamination is long ago decayed and of no harm, whatsoever, today. 

The plant had no leakage of the other more dangerous radioactive gases, such as caesium 137, which made Chernobyl much more deadly.  Caesium 137 has a half life of over 30 years, before it decays to half levels.  The worst case scenario would have been an explosion or full meltdown that could have released Uranium 235 from the nuclear reactor core.  It has a half life of nearly 704 million years!!!  😲 


The 1st Reactor at TMI operated fine for years before #2’s accident and continued, without problem, for the next 40.  The 40th anniversary of the Three Mile Island accident was in March 2019.  The entire plant closed in September 2019 due to financial difficulty.  I’m so glad we had the chance to visit the area and see it for ourselves.  Most of the historic places we visit don’t have any lingering dangers.  The war is over, the dictator dead, the people long gone.  But, the Three Mile Island disaster was unique because it reminds us that this could still pop up, again, today.  There are 58 nuclear plants with 97 reactors, and growing, in the United States.  No new plants were built for over 30 years after the TMI accident, but some are under construction, today.  Plants in the US (including TMI Reactor 1) and others all over the world have operated safely for decades.  Practices, regulations, training, licensing and safety procedures have had vast improvements because of and since the TMI disaster.  It taught the world much and the entire industry and governnment emergency response is safer, as a result.   

NRC nuclear power reactors in US

NRC File Photo, May 10, 2018.  Wondering if you’re close?  Nuclear Reactors & power plants in the US.  Interesting.  If you split the United States in 1/2, all but 3 are East of central Kansas.  Pennsylvania is still the state with the 2nd highest amount of nuclear reactors.  

What the Wheats think of the Three Mile Island Nuclear Accident Site:

Is it worth the drive?  To me, absolutely yes.  It’s not far out of the way, super close to Harrisburg & Hershey, just over an hour from Gettysburg and less than 2 from Philly.  As you’re visiting the rest of the cool stuff Pennsylvania offers (like our Eastern State Penitentiary visit/ guide), it’s an easy side trip on your travels.  Aside from Pennsylvanians, who can say they’ve been to Three Mile Island?!! 


Three Mile Island has become legendary in American history.  I like visiting sites of any historic event that I find interesting or moving or powerful and this was all 3.  I love to do a 360* view, see what’s close, walk the ground, examine the area, talk to people sometimes, and take it all in.  There isn’t a lot to see here, but it’s very cool to go where the disaster happened.  A dark event within my lifetime, it had an effect on me and everyone alive, then.  Movies, tv shows, books, and people still frequently refer to it.  There’s hardly a conversation on nuclear power that TMI doesn’t come up.  You can watch news footage and still get a chill, especially if you’re a Cold War era kid.  I like visiting shocking sites from history and TMI is one.  If you’d like to check it out and get some pics of the plant and area that was almost no more, check it out.  If you like dark history spots, it’s cool to get the pics and say you’ve been.  For kids & adults, going where history happened makes it all the more real.  The site of the worst nuclear power plant accident in the US.  One that was headed down a road and came very close to much, much worse.  I pray this is the only nuclear disaster site you’re ever able to visit in this country and that no more are created in the world.  



Three Mile Island Nuclear Power Plant Accident Site


  • TMI is a few miles South of Middletown, Pennsylvania.  It’s on a small island in the middle of the Susquehanna River on the West side of River Road/ PA Hwy 441. 
  • It’s 14 miles from Harrisburg, 12 from Hershey, less than 2 hours West of Philadelphia & 1 from Gettysburg.  

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Famed movies dealing with nuclear radiation contamination or nuclear war did a really good job at generating fear.  As kids, they scared us to death and I’m sure it made parents especially uneasy during those Cold War times from the late ’40s to 1991.  A few of the many that stick out in my mind as memorable include:



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Visit the Three Mile Island Nuclear Accident Site in Pennsylvania!