Three Mile Island

Three Mile Island in Harrisburg, Pennsylvania, contained the most serious commercial nuclear accident in U.S. history. The events that followed taught the U.S. a lesson learned about nuclear power and the damage it can cause. The Three Mile accident paved the way for reforms in the way nuclear power plants were operated and regulated. The location of the island, the accident, the meltdown, the aftermath, and the media circus were all critical points in the lessons learned.

The location of Three Mile Island is in the Susquehanna River, ten miles southeast of Harrisburg, Pennsylvania. The station is located on eight hundred and fourteen acres on an island surrounded by farmland. The Three Mile Island Nuclear Generating Station consists of four separate generators. The second generator, also known as TMI-2, is the one that failed during the accident. Even though the accident occurred, the island still created plentiful amounts of energy for Pennsylvania. The island is concreted now, but produced 6.2 billion kWh of electricity in 1999. The island was hardly known to anyone until the accident occurred which brought up many concerns of health and safety problems. Many people today still do not know where the island was and what its purpose was. Three Mile Island produced a significant source of energy for Pennsylvania and surrounding areas whenever it was running.

On an early morning of March 28, 1979, around 4:00 a.m., there was nothing unusual going on at the Three Mile Nuclear Generating station. Everything suddenly changed when during a maintenance routine, an automatically operated valve in the Unit 2 reactor closed when it shouldn't have due to either a mechanical or electrical failure. The generator became really hot because the water supply that cools down the generator was shut off. This caused pressure in the primary system to increase and in order for the pressure not to get too excessive, the pilot-operated relief valve opened up. After some of the pressure was let out the relief valve was supposed to close once it went down to a certain amount, but it didn't.

The electrical failure caused the operator to not know that the valve was still open, which led to cooling water pouring out of the valve and caused the reactor core to overheat. As a result of all of these things, the instruments that the operators read to know what was happening provided confusing information. The operators could not tell how much coolant was in the reactor core because they didn't have an instrument to show that, but instead had to guess on how much coolant there was. As the alarms and warning lights went off, the operators didn't realize that the plant was having an accident with the coolant level. The tubes holding the nuclear fuel began to melt since they became over heated which also caused fuel pellets to melt. Even though this was the most dangerous kind of nuclear accident, the radiation did not reach outside of the containment building nor did it release out into the environment. There were no immediate injuries or deaths reported from the radiation to the faculty workers.

There was a report that got out to the news that there was a meltdown of one of the reactor cores. According to the U.S. Nuclear Regulatory Commissions independent Rogovin Commission Report, the reactor was about half an hour away from an irreversible meltdown as it was described in the movie The China Syndrome. This movie came out just days before the near meltdown happened and was about the same things that happened on Three Mile Island. Reports indicate that ninety percent of the reactor core was damaged and fifty-two percent of it had melted down. The containment building and several other locations around the plant were contaminated. Officials were able to save the reactor from a complete meltdown by restoring enough coolant to the