Accident at Three Mile Island

Analysis of a sample of primary coolant taken on 30 March reported by English (1979) in The Kemeny Report, showed that about 10% of the inventory of rare gas, I and Cs fission products had been liberated from the fuel, but only about 0.1% of Te and less than 0.01 of alkaline and rare earths fission products (Table 2.6). Further samples of coolant taken 12 d later showed that leaching of refractory fission products had increased their concentrations by an order of magnitude. However, 

Nuclide Reactor inventory (EBq) to coolant or containment to atmosphere Activity to atmosphere (TBq) 

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Nuclear power has achieved an excellent safety record. Exceptions are the accidents at Three Mile Island in 1979 and at Chernobyl in 1986. In the United States, safety can be attributed in part to the strict regulation provided by the Nuclear Regulatory Commission, which reviews proposed reactor designs, processes appHcations forUcenses to constmct and operate plants, and provides surveillance of all safety-related activities of a utiUty. The utiUties seek continued improvement in capabiUty, use procedures extensively, and analy2e any plant incidents for their root causes. Similar programs intended to ensure reactor safety are in place in other countries. 

The accident at Three Mile Island unfortunately tlircatened the future of nuclear power in tlie United States and called into question the safety systems... 

Nuclear accidents at Three Mile Island, Pennsylvania, in 1979 and Chernobyl, Russia, in... 

Since this is a book on control and instrumentation, we might also mention that a high-level alarm and/or an interlock (a device to shut off the feed if the level gets too high) should be installed to guarantee that the tank would not spiU over. The tragic accidents at Three Mile Island, Chernobyl, and Bhopal illustrate the need for well-designed and well-instrumented plants. 

The world use of nuclear power to supply a nation s electricity varies widely by country. France, for example, gets around 75% of its electricity from nuclear power, and several other European countries get over half of their energy from this source. Approximately 20% of the electricity in the United States comes from 103 operating nuclear power plants. Nuclear is second only to coal, 50%, and ahead of natural gas, 15%, hydropower, 8%, and oil, 3%, as a source of electrical energy. Although once hailed by President Eisenhower in the 1950s as a safe, clean, and economical source of power, the US. nuclear industry has fallen on hard times in the last twenty-five years. Nuclear accidents at Three Mile Island, Pennsylvania,... 

The hardest part of engineering risk assessment has turned out to be the prediction of the modes of failure. Serious accidents at nuclear installations, such as those at Three Mile Island or at Chernobyl, have been caused by modes of failure that had not been analysed at all. For example, the report of the Presidents Commission on the Accident at Three Mile Island (Presidents Commission, 1979, p9) highlighted that the concentration of the assessment process on more obvious large break scenarios meant that the eventual mode of failure, which was a result of a chain of a number of more minor events, was not even considered. Despite the use of significant resources in the design process, the risk assessment had been unable to characterize the complex system adequately, a system that was totally human-made and defined. In particular, the risk assessment process had not been able to identify modes of failure caused by humans involved in the operations of the reactor behaving in unexpected ways. 

Table 2.6. Release of fission products in accident at Three Mile Island...

Campbell, D.O. (1979) Behaviour of iodine under accident conditions at Three Mile Island. The Accident at Three Mile Island (Kemeny Report). Reports of the technical assessment task force, Vol II, Appendix F. U.S. Govt. Printing Office, Washington D.C. 

Although the duration of construction was influenced by various factors, including the accident at Three Mile Island, economic conditions and power needs, the history and trend of extended times to obtain operating licenses was a motivation for the development of an alternate licensing process, which is defined in 10 CFR Part 52. The licensing process in 10 CFR Part 52 involves the possible submittal of a nuclear power plant design for certification and the approval of specific sites via an... 

It is normal for people to fear what they cannot detect. An experienced war correspondent said of the accident at Three Mile Island, At least in a war you know you haven t been hit yet Similarly, risks that may take years to show up are more likely to be feared. [26]... 

The Accident at Three Mile Island, Staff Report to the President s Commission, Nuclear Regulatory Commission, Washington DC, 1979. 

A particular aspect of water treatment is the rehabilitation of accidentally contaminated soils by radionuclides. This is well illustrated by the works carried out after the Cernobyl catastrophe. The incorporation of clinoptilolite into contaminated soils reduced the transport of heavy metals and radionuclides from soils into ground water and biomass (7). Union Carbide s IONSIV EE-95 (CHA) and A-51 zeolites (LTA) with excellent Cs+/Na+ and Sr2+/Na+ selectivities, respectively, have also been employed for decontamination of high activity level water in the reactor containment building from Cs+ and Sr2+ after the accident at Three Miles Island (5). The radioisotope loaded zeolites were then transformed into glasses for ultimate disposal. 

A wealth of new information about radiation exposure over the past decade prompted the revision of the BSS. First and foremost, a study of the biological effects of radiation doses received by the survivors of the atomic bombing of Hiroshima and Nagasaki suggested that exposure to low-level radiation was more likely to cause harm than previously estimated. Other developments—notably the nuclear accident at Three Mile Island in 1979 and that at Chernobyl in 1986, with its unprecedented transboundary contamination—had a profound effect on the public perception of the potential danger from radiation exposure. There were serious accidents with radiation sources used in medicine and industry in Mexico, Brazil, El Salvador and other countries. In addition, more has been discovered about natural radiation—such as household radon—as a cause of concern for health. Finally, natural radiation exposures of workers such as miners, who were not thought of as radiation workers, were discovered to be much higher than had been realised. 

Dohrenwend BP, Dohrenwend BS, Warheit GJ, et al Stress in the community a report to the president s commission on the accident at Three Mile Island. Ann N Y Acad Sci 365 159-174,1981... 

Fabrikant JI The effects of the accident at Three Mile Island on the mental health and behavioral responses of the general population and nuclear workers. Health Phys 45 579-586, 1983... 

Brookes, Malcolm J. 1982. Human factors in the design and operation of reactor safety systems. In Accident at Three Mile Island The Human Dimensions, ed. David L. Sills, C. P. Wolf, and Vivien B. Shelanski, 155-160. Boulder, Colo. Westview Press. 

Kemeny, J.G. (chairman) (1979) Report of the President s Conunission on the accident at Three Mile Island The need for change the legacy of TMP, President s Conunission on the accident at Three Mile Island, 2100 M Street, NW Washington, DC 20037. 

ABSTRACT The analysis of events during the accident at Three Mile Island concluded that the accident was due to confused control room operators with inadequate instrumentation and inaccurate procedures. Therefore, the United States Nuclear Regulatory Commission (USNRC) called for improved nuclear reactor operator training and Emergency Operating Procedures (EOPs). 

During the nuclear reactor accident at Three Mile Island in 1979, an unknown mass of fuel pellets melted, and the molten fuel fell into water at the bottom of the reactor. Assume that the melting fuel pellets were pure UO2 and were initially at 900 C. Further assume that the water was initially at 8°C and that sensors indicated the final temperature of the water was 85°C. 

The potential dangers of nuclear power were tragically demonstrated by the accidents at Three Mile Island, Pennsylvania (1979), and Chernobyl in the former U.S.S.R. (1986). Both accidents resulted from the loss of coolant to the reactor core. The reactors at Three Mile Island were covered by concrete containment buildings and therefore released a relatively small amount of radioactive material into the atmosphere. But because the Soviet Union did not require containment structures on nuclear power plants, the Chernobyl accident resulted in 31 deaths and the resettlement of 135,000 people. The release of large quantities of 1-131, Cs-134, and Cs-137 appears to be causing long-term health problems in that exposed population. 

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