Three Mile Island nuclear power plant, Pennsylvania

Public opposition to commercial nuclear power plants began with the misperception that the plants could explode like nuclear weapons. The nuclear industi-y made progress in dispelling this misperception, but suffered major setbacks when an accident occurred at the Three-Mile Island nuclear power plant in Pennsylvania and at the Chernobyl nuclear power plant in the USSR. 

On March 28, 1979, a loss of containment incident occurred at the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania. An overheated reactor released radioactive steam and water to the atmosphere resulting in a mass evacuation of the surrounding community. Although no direct injuries were attributed to the incident, environmental effects were later observed and public outcry resulted in a slowdown in the growth of the nuclear power industry. 

At the Three Mile Island Nuclear Power Plant in Pennsylvania on March 28, 1979. a hose contributed to the front-page event. In short, a nuclear reactor overheated, a small amount of radioactivity escaped, and the public confidence about the safety of nuclear power was shattered. It is believed by the technical community that no one was likely to be harmed by this release, but it led to a slowdown in the growth of nuclear power in the United States. [9]... 

The gas that you see coming from the towers of the Three Mile Island nuclear power plant in Pennsylvania is all water vapor. Few chemical pollutants are released during the normal operation of a nuclear plant. Both equipment failure and human error resulted in overheating of the reaction chamber and a partial meltdown of fuel rods at this power plant in 1979. As a result, the building surrounding the reactor became flooded with water contaminated with radioactive material, and radioactive gas was released into the atmosphere. ... 

The 1970s were hard times for the nuclear industiy. The decade opened with the first Earth Day (April 22), which featured thousands of teaching events, many of them aimed at halting further nuclear power development, and ended with the accident at the Three-Mile Island nuclear plant in Pennsylvania. In... 

Although nuclear processes offer the potential for an abundant source of energy, no nuclear power plants have been built in the United States for some time. In addition to the fear of a malfunction in such a plant (as happened at the Three Mile Island nuclear plant in Pennsylvania) or the threat of a terrorist attack against such a plant, there is the very practical problem of the regular disposal of the waste material from a nuclear power plant. Discuss some of the problems associated with nuclear waste and some of the proposals that have been put forth for its disposal. 

There have been three notorious accidents at nuclear power stations. The first occurred at the Three Mile Island (TMl) generating plant near Middleton, Pennsylvania, in 1979. The TMI reactor is of the light-water type, in which water is used as the moderator and coolant. In this accident, some coolant (also the moderator) was lost the chain reaction in the reactor stopped because there were too few slow neutrons. However, radioactive decay of the fission fragments continued, causing the fuel rods to get very hot. A partial meltdown resulted and, in turn, caused a fracture in one of the reactors. The fracture permitted the venting of a small amount of radioactive steam into the atmosphere. The reactor is now sealed, but electronic robots have discovered substantial damage to the fuel rods. 

The accident at the Three Mile Island (TMI) plant in Pennsylvania in 1979 led to many safety and environmental improvements (4—6). No harm from radiation resulted to TMI workers, to the pubHc, or to the environment (7,8), although the accident caused the loss of a 2 x 10 investment. The accident at the Chernobyl plant in the Ukraine in 1986, on the other hand, caused the deaths of 31 workers from high doses of radiation, increased the chance of cancer later in life for thousands of people, and led to radioactive contamination of large areas. This latter accident was unique to Soviet-sponsored nuclear power. The Soviet-designed Chemobyl-type reactors did not have the intrinsic protection against a mnaway power excursion that is requited in the test of the world, not was there a containment building (9—11). 

Releases of radioactive materials from nuclear power plants have occurred, as at Three-Mile Island, Pennsylvania. In such situations, releases may be sufficient to require evacuation of residents. 

Nuclear power plants in the United States are supposed to be designed well enough to prevent accidents as serious as the one at Chernobyl. Nevertheless, the Three Mile Island plant in Pennsylvania, an aerial view of which is shown in Figure 22-14Z). experienced a partial meltdown in 1979. This accident was caused by a malfunctioning coolant system. A small amount of radioactivity was released into the environment, but because there was no explosion, the extent of contamination was minimal. 

Two accidents of vastly differing severity have occurred at nuclear power plants. On 28 March 1979, an accident occurred in the nuclear power plant at Three Mile Island, Pennsylvania, USA. The radiation was contained and the small amount released had negligible effects on the health of individuals at the plant. On 26 April 1986 an accident occurred in the nuclear power plant 10 miles from the city of Chernobyl, then part of the Soviet Union. The chain reaction in the radioactive core of one of the four reactors became uncontrolled. Steam pressure rose to dangerous levels there were several explosions and a subsequent fire took several hours to extinguish. Large amounts of radioactive material were scattered over a wide area and into the atmosphere (later descending in a dilute form in rain all over the world). 

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,... 

Even if terrorists succeeded in detonating an explosive at a reactor site, the health consequences would be limited. The reactor accident at the Three Mile Island, Pennsylvania nuclear power plant caused a small release of radiation, insufficient to cause any radiation injuries. Bypassing several safety systems caused the Chernobyl reactor incident, involving two explosions, fires and reactor core meltdown. This accident caused the following early phase health effects (1) ... 

The worst nuclear power accident in the U.S. occurred at the Three Mile Island plant in Pennsylvania. In this accident no one was killed and no one was directly injured. The event at Three Mile Island occurred from faulty instrumentation that gave erroneous readings for the reactor vessel environment. A series of equipment failures and human errors along with inadequate instrumentation allowed the reactor core to be compromised and go into a partial melt. The radioactive water that was released from the core was confined within the containment building and very little radiation was released. In the Three Mile Island incident, the safety devices worked as planned and prevented any serious injury. This accident resulted in improved procedures, instrumentation, and safety systems being implemented. 

Some major accidents at nuclear power plants, such as the leak of radioactivity from the Three-Mile Island facility in Pennsylvania in 1979 and the far more serious one from the Chernobyl plant in Ukraine in 1986, have resulted in high levels of mistrust and fear in many people. Yet, despite these problems, nuclear energy remains an important source of electricity. In the late 1990s, nearly every European country employed nuclear fission in power plants, and such plants provide the majority of electricity in Sweden and France. Today, the United States obtains about 20% of its electricity from nuclear power plants, and Canada slightly less. 

A great deal of controversy now exists about the efficiency of the safety systems in nuclear power plants. Accidents such as the one at the Three Mile Island facility in Pennsylvania in 1979 and the one at Chernobyl in the Soviet Union in 1986 have led many people to question the wisdom of continuing to build fission-based power plants. 

Nuclear power plant accidents at Three Mile Island, Pennsylvania, and Chernobyl, Ukraine, focus world attention on the dangers associated with nuclear power. 

Although nuclear power reactors really do have a good safety record, the distrust and fear associated with radiation make most people sensitive to safety issues and accidents. The most serious accident to occur in the United States happened in 1979 at the Three Mile Island Plant in Pennsylvania. A combination of operator error and equipment failure caused a loss of reactor core coolant. The loss of coolant led to a partial meltdown and the release of a small amount of radioactive gas. There was no loss of life or injury to plant personnel or the general population. 

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. 

The development of nuclear power was in full swing in the 1970s when the accident occurred at the Three Mile Island Unit 2 nuclear power plant near Harrisburg, Pennsylvania, in 1979. The reactor was a PWR supplied by Babcock Wilcox Corporation. As a result of this accident, reactor construction came to a standstill as the cause of the accident was analyzed, and the design of reactors under construction was modified to meet new licensing requirements. Costs increased dramatically and many orders for reactors were canceled. The impact of this accident was felt primarily in the United States. 

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