More than four decades ago, the United States witnessed the most serious accident at a commercial nuclear power plant in its history.
At 4 a.m. on March 28, 1979, a unit at the Three Mile Island facility near Harrisburg, Pennsylvania, partially melted down, releasing a small amount of radiation and spurring thousands of people to evacuate the surrounding area. Although it had no detectable health effects on plant workers or the public, the accident’s aftermath resulted in sweeping changes in how the nation handled nuclear emergencies, according to the U.S. Nuclear Regulatory Commission.
“Three Mile Island was obviously the seminal moment in nuclear power,” Scott Odom, the program manager for emergency preparedness at the Tennessee Valley Authority, said in an interview. “A great deal was learned from that. There was a whole suite of regulations that came out at that time, and it completely changed the entire framework of how you prepared for it and responded to emergencies.”
Today, TVA runs regular drills at its three nuclear power plants, including Sequoyah in Hamilton County and Watts Bar in Rhea County. On Dec. 11, the agency participated in a test at Sequoyah, during which federal inspectors examined TVA’s ability to distribute timely information to the public. About 42% of the power TVA delivered to customers in its 2023 budget year was nuclear energy.