Real Story. Real Stupid.
"Homer, your bravery and quick thinking have turned a potential Chernobyl into a mere Three Mile Island." -Mr. Burns
Three Mile Island is a nuclear generating station located in Dauphin County, Pennsylvania. On March 28th, 1979 there was a series of unfortunate events (compounded with human error) that lead to the biggest nuclear disaster in US history. This nuclear accident could have been avoided and is a cautionary tale that is worth telling.
The story begins in the early morning hours of that fateful day. Reactor 1 has been shut down for refueling since the previous day. Reactor 2 is running at nearly full power when a minor malfunction sets off a series of automatic responses in the coolant system. One of the automatic responses is the opening of a relief valve on top of the pressurizer. This pressure relief valve is significant in our cautionary tale. This valve was supposed to close once the pressure normalized and if that had been the case, the accident at Three Mile Island would never have happened. The valve failed to close and stuck in the open position. Operators in the control room have not been properly trained and believe coolant is being pumped into the system as it should be but it is actually being diverted due to the valve. This causes the reactor to overheat. An operator overrides the automated cooling system. Coolant is mistakenly allowed to spew out for over two hours and radiation levels rise inside the plant.
Shortly before 7am, a site emergency is declared, and half an hour later a general emergency is declared. That afternoon there is a hydrogen explosion in the containment building. It isn't until the next day that the extent of the core damage and possible release of radioactive material is realized.
Residents within a ten-mile radius are advised to stay indoors with windows closed and ventilation systems off. Then pregnant women and small children within five miles of the site are advised to evacuate. Farmers are then told to keep their animals under cover and feed them only stored feed. Next, the evacuation radius is extended to a twenty-mile radius.
Three days into the accident it is discovered that there is a hydrogen bubble trapped in the dome of the pressure vessel. There is fear that this will cause an explosion that could lead to a large scale leak of radioactive material. Instead, the hydrogen was slowly vented out into the atmosphere and the risk of explosion was averted.
The lack of coolant caused a partial meltdown of the core in reactor 2. This caused a leak of radioactive gases and iodine into the environment. Depending on which study you read or believe, this leak led to death and disease for wild animals and livestock in the area. It leads to an increase in non-specified cancer, leukemia, and thyroid cancer in people. Other studies suggest there was no impact on the health of animals or humans.
Cleanup of the radioactive contamination began in August of 1979 and was complete in December of 1993. The total cost to clean up Three Mile Island was $1 billion. The accident caused $2.5 billion in property damage to the local area.
The Three Mile Island accident could have been avoided a few ways. One problem was the poor training for the shift operators. They were not fully aware of how the auto-response systems operated and subsequently misunderstood information and turned the system off. The panel design was flawed in that it was confusing for shift operators to not see important warning lights and to misread important features. The reason the valve became stuck was due to improper work that operators did hours earlier to fix a blockage in another area of the coolant system.
My two cents: You should probably have well-trained operators when you are dealing with 150 tons of Uranium! An instrument panel that is user-friendly would also be recommended. Emergency drills anyone? There are certain jobs that require exceptional help and guidelines, I think we know that now.
Rating: I'm a little stumped on how to rate this man-made disaster. I'm going to say two out of five possible slow claps for the Three Mile Island f*ck up just because I'm sick of reading about it and I want to wrap this up. You get a gold star if you are actually still reading.
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