Three Mile Island Accident Study

The basic causes of the meltdown were the damages to backup generators on reactors 1 through 3 by the sea water. This forced the emergency lights and cooling system to shutdown (which resulted in an overheating of the reactors). What made the situation worse is that Japanese officials were in a state of panic after the disaster. This is because they did not realize that the cooling systems were shut off and that the problem was compounded from the lack of response. ("Fukushima Utility")

The Three Mile Island TMI-2 incident had a large impact on world history. It showed America their first glimpse of what can happen with nuclear power, it foreshadowed the Chernobyl incident eight years later, it decreased public opinion of nuclear power, and it increased safety standards for nuclear reactors across the world. Three Mile Island is a nuclear power plant in Southeastern Pennsylvania with two nuclear fission reactors. On March 28, 1979, reactor two suffered a partial core meltdown that caused a widespread radiation scare. Although negligible amounts of radiation actually escaped into the atmosphere, nearby towns were left deserted for a couple days until the media finally got the story straight and the government released an official

On May 28, 1979, around 4 a.m. in Harrisburg, Pennsylvania at Three Mile Island nuclear power plant, the worst nuclear accident in United States history occurred (Backgrounder…). The Metropolitan Edison Company was operating Reactor 2 as normal but then it suddenly shutdown due to a rise in the temperature of the coolant feed. When functioning properly, the reactor is cooled by a steady stream of a coolant water that flows into and then out of the reactor which is the cooled and recycled back to the reactor. However, the temperature of the inlet, coolant feed increased and caused the reactor to

Carl Michelson, a science-fiction writer with adept expertise in nuclear engineering and a respected advisor in the world of nuclear reactors also brings to attention a fault in the Babcock and Wilcox pressurizer. He notes that a U-shaped pipe between the pressurizer and coolant loop could prevent water from flowing, thus filling the pressurizer beyond a safe limit while draining the reactor. Yet again, this warning was halted by the choking grip of bureaucratic

On the 11th of March, 2011, a 9.0-magnitude earthquake struck near the eastern coast of Japan. Emergency shutdown procedures went into effect when the earthquake was spotted, but this was not the main cause of the destruction of the nuclear reactor. The first line of defense was to immediately stop the nuclear fission within the reactor by inserting neutron absorbing rods to stop the reaction. After the engineers successfully stopped the nuclear fission reaction, immense heat and pressure was still prominent and needed to be relieved as soon as possible. Fresh water was brought in and dumped onto the rods but a tsunami inevitably followed as soon as the earthquake was felt as the source of the natural disaster was on the ocean floor. The tidal wave severely damaged the power supply system that was meant to maintain the flow was cold water. On March 12, 2011, diesel powered generators were initiated in an attempt to alleviate the failure of the generators that were powering the entire plant. Unfortunately, the diesel powered generator was insufficient enough to cool the large reactor as the heat building up within was accumulating in large amounts; more than what nuclear engineers originally presumed. Water continued to evaporate causing a hydrogen gas to form when the fuel rods underwent a chemical reaction with the steam. Hydrogen gas is an important element to take into consideration as too much of this element can cause an explosion within the reactor. Workers quickly

An author from Engineering.com named, The Engineer wrote a fairly descriptive article on the events that took place at Three Mile Island in October of 2006. The Three Mile Island incident occurred on March 27, 1979. Two men were cleaning a clog in an ion-exchange tank using compressed air from a general-purpose air system. There was a water line and another compressed air system that controlled valves in the plant. The Engineer (2006), points out that the 3 systems have similar fittings and a hose was connected between the instrument air system and the water line. This led to a loss of feed water to the steam generators and no way to cool down the reactor. With no way to be cooled, the system

Figure 1 shows normal operation of a reactor along with the meltdown process to put in to perspective the summary of Fukushima Daiichi disaster events. In Short it does something like this: The Tohoku earthquake, March 11 2011, triggered a tsunami both of which caused damage to the 4 power plants at Fukushima. The damage caused equipment failures and a loss-of coolant accident due to the in ability to supply the reactors with cooling

On Saturday, April 26, one of the reactors at the Chernobyl nuclear plant became very unstable as a routine shutdown was taking place. This was not the first time when reactor number four was shut down. There was a previous time when the turbine of the reactor was not functioning as fast due to the voltage regulators. The

The crew unintentionally let steam voids form in the reactor's cooling water as it passed through the core. One of the flaws of the reactor design was its tendency to generate a sudden and uncontrollable burst of power if large steam voids are allowed to form in the reactor core, as happened during the test (Gillette 1986). In addition to the documented problem of the steam voids inherent in the design, poor manual operation of the reactor had caused the reactor to be in an even more unstable state than usual.

The time schedule for the experimental operation suffered an unexpected delay. The Kiev power grid suffered a shortage of electricity in the grid. The control grid operator requested the Chernobyl facility to delay the operation in order to assist in the electricity demand of the peak hour. The Chernobyl director agreed to the request and officially postponed the operation until their energy output was no longer necessary. Despite the delay, the staff of reactor four proceeded in necessary preparation for experiment. The crew disabled non-energy affecting routines and the passive cooling system responsible for maintaining the reactor four's core; the system supplied emergency

The earthquake made the nuclear leak, and the nuclear leak not only affected the human activities, but also affected the environment as well. The nuclear radiation affects the soil and the sea around the station. Many fish died and the sea was polluted.

This happened due to a flaw in the RBMK design (Smith and Beresford, 2005). In most reactors, a pending disaster would lead to the machine reducing its power, and avoiding this type of disaster (Smith and Beresford, 2005). However, in this design of reactor, when water or steam is lost, power levels rise, steam is created, and toxins can be released (Smith and Beresford, 2005). Thus, the radiation from this explosion was spread in the air.

For 83 minutes, reactor number 4 exploded, sparking the first disaster of its kind in the history of mankind (Rybar). The blaze would last for ten days, making it essentially impossible for anyone to enter the plant in order to slow or stop the amount of radioactive materials the were leaking into the

On April 26th, 1986, operators at the Chernobyl Power Plant in Chernobyl, Ukraine, ran what they thought to be a routine safety test. But fate was not on the side of these operators. Without warning, reactor #4 became unstable, as it had been operating at a low power for a possible shutdown and the reactor’s design caused it to be unsafe at this level of power. Internal temperatures rose. Attempts to cool the system produced the opposite effect. Instantly, the nuclear core surged with power. At 1:23 p.m., the reactor exploded. The first blast ripped off the reactor's steel roof. The second blast released a large plume of radiation into the sky. Flames engulfed the building. For ten long days,

On March 28, 1979, near Middletown, Pennsylvania, a Unit 2 (TMI-2) reactor partially melted down. The reactor released small amounts of radioactivity, but none of it had any detectable health effects on employees or workers at the plant. Then, from the years of 1980 to 1993, workers helped to clean up the accident. This accident created a need for better safety precautions and work operations. It changed emergency response planning, reactor operator training, human factors engineering, and radiation protection, which are only a few nuclear power plant operations that demanded to be fixed (“Backgrounder on the Three Mile Island accident”, 2014). As stated by Columbia Electronic Encyclopedia in the article “Three Mile Island” (2013), “The accident also increased public concern over the dangers of nuclear power and slowed construction of other reactors; no new reactors were approved for construction following the accident until 2012.” There were two nuclear reactors located at the plant, both owned by General Public Utilities, however only one of the two failed to work (Bowen, Robert M., 1983). This accident had a large impact on how stable mechanisms in nuclear situations need to be as well as how situations such as this one are handled.