What Happened at Three Mile Island?

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This research paper discusses the Three Mile Island incident to include what started it, the results in the aftermath, and how it could have been prevented. The Three Mile Island Unit 2 (TMI-2) reactor, near Middletown, Pa., partially melted down on March 28, 1979. This was the most serious accident in U.S. commercial nuclear power plant operating history, although its small radioactive releases had no detectable health effects on plant workers or the public. Its aftermath brought about sweeping changes involving emergency response planning, reactor operator training, human factors engineering, radiation protection, and many other areas of nuclear power plant operations. It also caused the NRC (Nuclear Regulatory Commission) to tighten and heighten its regulatory oversight. All of these changes significantly enhanced U.S. reactor safety. A combination of equipment malfunctions, design-related problems and worker errors led to TMI-2's partial meltdown and very small off-site releases of radioactivity.

What Happened at Three Mile Island?
There are three primary reasons that were directly responsible for what happened at Three Mile Island. Equipment design, mechanical malfunctions, and human error were the key contributors to the Three mile Island Unit 2 reactor melt down. The accident began about 4 a.m. on Wednesday, March 28, 1979. Either a mechanical or electrical problem stopped the water pumps from cooling the reactor core. This made the reactor overheat to the point of rupturing the long tubes that hold nuclear fuel pellets.
Instantly, the pressure in the primary system (the portion of the plant that is nuclear) started to rise. As a means to manage that pressure, the pilot-operated relief valve (the top valve of the pressur...

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...to what actually happened at Three Mile Island. These organizations reported what they know to be true to the best of their accounting of the incident. With the newly implemented safety standards in place, power plant operators may not see another accident like Three Mile Island’s Unit 2 reactor due to adequate training, and regulated policies holding them to standard.

Works Cited

ND. (2014, April 25). Backgrounder on the Three Mile Island Accident. Retrieved from U.S.N.R.C: http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/3mile-isle.htm

ND. (2010, August). NEI. Retrieved from Nuclear Energy Institute: http://www.nei.org/Master-Document-Folder/Backgrounders/Fact-Sheets/The-Tmi-2-Accident-Its-Impact-Its-Lessons

Keebler, J. R. (2013, March 04). kmuw. Retrieved from kmuw: http://kmuw.org/post/human-factor-how-three-mile-island-could-have-been-prevented
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