The Three Mile Island Nuclear Accident and Its Impact on U.S. Energy

How the Accident Helped Kill the U.S. Nuclear Power Industry

3 mile island nuclear power plant

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The Three Mile Island accident was a meltdown at a nuclear power plant in Middletown, Pennsylvania. It occurred on March 28, 1979. Officially, it caused no deaths. But unofficial investigations and lawsuits claimed there were above-average rates of cancer and birth defects in the surrounding area.

The accident halted the development of the U.S. nuclear power industry for 30 years. During that time, no new nuclear power plants were approved. Several that were under construction at the time of the accident were completed. 

As a result, the United States lost its competitive edge in nuclear engineering ability. It also relied more heavily on coal and natural gas to power electric generation. That added a lot of greenhouse gases to the atmosphere than nuclear energy would have. As a result, global warming has caused more extreme weather events, rising sea levels, and many other climate change effects.

Key Takeaways

  • The Three-Mile Island Incident was a nuclear power plant that melted down in Middletown, PA in 1979.
  • The accident changed the perception of nuclear energy in the United States, stopping future projects.
  • Nuclear plant projects began to reappear in 2007, with the hope to reduce the U.S.'s dependence on oil.

What Happened

The Three Mile Island plant was located in Middletown, Pa. It had two pressurized water reactors. TMI-1 entered service in 1974 and still operates safely. TMI-2 was brand new when the accident occurred.

At 4 a.m. on March 28, a cooling circuit malfunctioned, allowing the primary coolant to overheat. The reactor shut down immediately, and the release valve opened for 10 seconds, which allowed enough coolant to escape to reduce pressure and heat. But the valve got stuck in the open position, and as a result, all the coolant was released. Unfortunately, there wasn't an instrument that could have alerted engineers that this had happened.

New coolant rushed into the tank, but the engineers now thought that there was too much, so they reduced the flow. The remaining coolant turned to steam. The fuel rods overheated, melting the protective coating, which released radioactive material into the coolant. When the steam was released, the radioactive contaminant was released into the surrounding area.

Fortunately, the amount of radioactive material released was not enough to harm local food supplies, animals, or people.

The TMI-2 reactor was shut down. It took 12 years and cost $973 million to decontaminate to low levels of radiation. There were 10.6 megalitres of radioactive coolant that were processed, stored, and safely evaporated. About 100 tons of damaged radioactive fuel was put into 342 canisters. They were shipped to the Idaho National Laboratory and stored in concrete containers.

Three Mile Island Today

According to the World Nuclear Association, no verifiable health effects were found. Still, the following occurred:

  • The Pennsylvania Department of Health followed the health of the 30,000 people who lived within five miles of Three Mile Island. It was discontinued after 18 years when no evidence of unusual health effects was shown.
  • The Harrisburg U.S. District Court dismissed a 17-year class action lawsuit in June 1996. Judge Sylvia Rambo said there was no proof to substantiate the plaintiffs' claims of health damages from the accident. The appeal is before the U.S. Third Circuit Court of Appeals.
  • At least a dozen studies assessed the release of radiation and possible effects. None found adverse health effects. 

On the other hand, several documents allege that there was damage. They claim that the government is not being completely honest. For example:

  • "Three Mile Island: The People's Testament," a book based on interviews with 250 residents, says that many people reported diseases that were consistent with exposure to nuclear radiation contamination. Another book, “The People of Three Mile Island,” documented similar reports.
  • A local survey of 450 residents in the area found nine cancer deaths between 1980 and 1984. That's more than seven times the normal rate.
  • Hundreds of lawsuits were settled out-of-court. Millions of dollars compensated parents of children born with birth defects in the area. 

A 2009 article, “Startling Revelations About the Three Mile Island Nuclear Disaster,” reveals many contradictions to the government’s claim that the Three Mile Island tragedy did not pose any public threat.

Economic Impact 

Construction of new nuclear plants was halted for 30 years after the accident. Today, there are 96 reactors in use, supplying 20% of the nation's electricity. The Department of Energy supports more nuclear plants as a way to decrease U.S. reliance on foreign oil and to cut greenhouse gas emissions.

In 2007, companies once again applied to the U.S. Nuclear Regulatory Commission to build new plants. Since then, five have begun construction, and 12 more companies are looking into it.

The application process takes around five years and construction taking another four years.

The DOE asked Japan to assist in developing new nuclear power plants. Japan has more expertise in advanced, fast reactors that produce less radioactive waste while producing more energy. Former U.S. Energy Secretary Samuel Bodman admitted that Japan has the best scientists and engineers for these new types of reactors.

Comparison With Other Disasters

The economic cost of the Three Mile Island disaster is nowhere near the expense of other nuclear power plant accidents. Japan's nuclear meltdown could cost $200 billion. The Chernobyl nuclear disaster cost several hundreds of billions of dollars.

In the United States, Hurricane Katrina was the most expensive U.S. disaster. It cost between $125 billion to $250 billion. It reduced gross domestic product growth to 1.3% in the fourth quarter of 2005. It affected 19% of U.S. oil production and briefly spiked gas prices to $5 a gallon.