“THREE MILE ISLAND” Accident

From the day, when nuclear power was introduced to the world, although “Super Power Nations” want to establish and develop the technology of nuclear power, most of the countries refuse it because of it’s nature of being more disadvantages. But the super power nations such as U.S.A, Russia, North Korea, Iran and etc, still want to prove their power to the entire world. As a result of it, we have to come across lots of accidents and incidents, in the process and development of nuclear power every day.

In the whole history, the most dangerous and most significant accident in the American commercial nuclear power generating industry is the “Three Mile Island” which was owned and operated by General Public Utilities and the Metropolitan Edison Co. which is situated near Harrisburg, Pennsylvania. It may be the most significant in the world also.

THE ACCIDENT

At approximately 4:00 a.m. on March 28, 1979 the main feed water pumps in the non-nuclear cooling system of reactor 2 of the Three Mile Island nuclear power plant failed. This caused cooling water to drain away from the reactor resulting in partial melting of the reactor core. Operator errors, a stuck valve, faulty sensors and design errors together resulted in a release of approximately one thousandth as much radiation as during the Chernobyl explosion.

Fortunately about 18 billion curies of radiation that could have been released were held by the containment structure around the reactor. This caused some advocates to think that serious nuclear accidents will not occur in the United States. However, many experts have claimed that only luck kept the accident from being worse. The reactor core, according to them, was only just short of becoming hot enough to totally melt down. Complete melt-down was only prevented by immediate implementation of safety measures.

OUTCOMES

• It is very uncertain how much radiation was exactly released at the nuclear accident. It is estimated that this was about 2.5 million curies.

• A few days after the accident had occurred all children and pregnant women were evacuated from an 8 km radius of Three Mile Island as a safety precaution.

• Radiation from the Three Mile Island reactor has contributed to the premature deaths of some elderly people that lived in the region.

• Dairy farmers reported that many animals have died consequential to the accident and local residents have developed cancers. Some studies suggested that premature deaths and birth defects also resulted from the nuclear melt-down.

• The reactor cleanup started in August 1979 and officially ended in December 1993 at a cost of around 975 million dollars.

• From 1985 to 1990 almost 100 tonnes of radioactive fuel were removed from the site. Reactor 2 had been online only three months, but now had a ruined reactor vessel and was unsafe to walk in; therefore it has been permanently closed. Reactor 1 was restarted in 1985, but many plans for building new reactors of the same type were dismissed later.

Let’s move on to the relevant topic, the investigations and legal activities for the case. “Three Mile Island” will be typed as “TMI” later

INVESTIGATIONS

• Several state and federal government agencies mounted investigations into the crisis, the most prominent of which was the President's Commission on the Accident at Three Mile Island, created by Jimmy Carter in April 1979.

• The commission consisted of a panel of twelve people, specifically chosen for their lack of strong pro- or antinuclear views, and headed by Chairman, John G. Kemeny, president of Dartmouth College. It was instructed to produce a final report within six months, and after public hearings, depositions, and document collection, released a completed study on October 31, 1979.

• The heaviest criticism from the Kemeny Commission concluded that "fundamental changes were necessary in the organization, procedures, and practices’and above all - in the attitudes' of the NRC [and the nuclear industry.]" Kemeny said that the actions taken by the operators were "inappropriate"

• But that the workers "were operating under procedures that they were required to follow, and our review and study of those indicates that the procedures were inadequate" and that the control room "was greatly inadequate for managing an accident

• The Kemeny Commission noted that Babcock and Wilcox's PORV valve had previously failed on 11 occasions, 9 of them in the open position, allowing coolant to escape.

LEGAL ACTIONS

• The TMI accident enhanced the credibility of anti-nuclear groups, who had predicted an accident,^] and triggered protests around the world.

• The American public were concerned about the release of radioactive gas from the TMI accident and many mass anti-nuclear demonstrations took place across the country in the following months.

• The largest one was held in New York City in September 1979 and involved two hundred thousand people

• In 1981 citizens' groups succeeded in a class action suit against TMI, winning $25 milllion in an out-of-court settlement. Part of this money was used to found the TMI Public Health Fund.

• In 1983, a federal grand jury indicted Metropolitan Edison on criminal charges for the falsification of safety test results prior to the accident.

• Under a plea-bargaining agreement, Met Ed pleaded guilty to one count of falsifying records and no contest to six other charges, four of which were dropped, and agreed to pay a $45,000 fine and set up a $1 million account to help with emergency planning in the area surrounding the plant.

• According to Eric Epstein, chair of TMI Alert, the TMI plant operator and its insurers paid at least $82 million in publicly documented compensation to residents for "loss of business revenue, evacuation expenses and health claims".

• Also according to Harvey Wasserman, hundreds of out –of-court settlements have been reached with alleged victims of the fallout, with a total of $15m paid out to parents of children born with birth defects.

Continuously we will look on the topic of the reasons for the accident and lessons learned from the incident. All these will be from my point of view.

FACTS REVIELED AFTER THE ACCIDENTS

• From the Kemeny Commission’s report its said that PORV valve had previously failed on 11 occasions, 9 of them in the open position, allowing coolant to escape. Though it was happened by the hands of workers, workers just do what the management feels. This fact tells us how much the management got care of it and their negligence.

• The entire sequence of events at TMI had been duplicated 18 months earlier at another Babcock and Wilcox reactor, owned by David-Besse. The only difference was that the operators at Davis-Besse identified the valve failure after 20 minutes, where at TMI it took 2 hours and 20 minutes; and the Davis-Besse facility was operating at 9% power, against TMI's 97%.

• The engineers warned the management about the problem of the valve several times, the management refused the appeal by showing their priority in the company. They didn’t mind the problem clearly and they just saw that problem in their way; they try to show the engineers, that they were managers because of knowing everything.

• From the early days the company structure was created, there is being a conflict between the engineers and the management; it’s become a usual fact in the company level. In my view this is because of the misunderstanding of both the party, mostly in the side of management level.

• It’s not good for the development of the company also, because such similar occurrence

have occurred not only in this case, but in many times such as in the “Columbia” space shuttle. My opinion is the management should hear to the engineer’s side’s aspects in order to avoid such accidents.

LESSONS LEARNED BY THE INCIDENT

• Three Mile Island has been of interest to human factors engineers as an example of how groups of people react to and make decisions under stress.

• There is now a general consensus that the accident was exacerbated by wrong decisions made because the operators were overwhelmed with information, much of it irrelevant, misleading or incorrect.

• As a result of the TMI-2 incident, nuclear reactor operator training has been improved. Before the incident it focused on diagnosing the underlying problem; afterward, it focused on reacting to the emergency by going through a standardized checklist to ensure that the core is receiving enough coolant under sufficient pressure

• Improvements in quality assurance, engineering, operational surveillance and emergency planning have been instituted.

• It was criticized Pennsylvania's preparedness, in the event of a nuclear accident, at the time for not having potassium iodide in stock, which protects the thyroid gland in the event of exposure to radioactive iodine, as well as for not having any physicians on Pennsylvania's equivalent to the Nuclear Regulatory Commission.

CONCLUSION

By studying the stuffs it’s clear, this accident was happened by the misunderstand between the two parties; the managers and the engineers. It’s not only the misunderstanding, but it’s a kind of being an one man show. That is the managers always try to show their ability of making decisions. But in most of the technical cases it goes wrong. They have to change their mind in order to develop their company and their nations. So by considering everyone’s thoughts, we should conclude or we should make decisions especially in the case of managers.