On 28 March 1979, one of the two nuclear reactors on Three Mile Island in Pennsylvania experienced a partial meltdown. It was the worst commercial nuclear power plant accident in United States history. The meltdown started with a pressure relief valve that was left open and a loss of coolant accident that wasnt noticed. Nuclear reactors generate internal heat and this heat is converted to usable electrical energy through the use of a coolant system. Due to the stuck valve, coolant leaked. Employees on duty believed their instrument panels were registering correctly, but they were actually all jacked up. When the leak was eventually discovered, it was repaired but a hydrogen gas bubble formed, which leaked radiation into the air. Tests were performed in the surrounding cities and did indicate a higher rate of thyroid cancer but no causal link could be found. Environmental activists would use the accident to lobby the government for better safety regulations, which leads to the development of the Institute of Nuclear Power Operations. The site closed because it was too contaminated and damaged. Clean up began in 1979 and ended 14 years later. It was an economic nightmare and cost $1 billion for clean up alone.
