Three Mile Island , nuclear power

In the past only two nuclear accidents (Three Mile Island and Chernobyl) were widely reported, while over 100 went unreported. These other accident were not caused by only earthquakes, design errors or terrorist acts, but more recently also by software virus attacks through the Internet. For example, on January 25, 2003 a Slammer worm penetrated the private computer network of Ohio s Davis-Besse nuclear power plant, and stopped its control computer. The only reason a meltdown did not result is because the plant was not in operation. 

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 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. 

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

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. 

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... 

March. An accident occurs at the Three Mile Island nuclear power plant in New York. 

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. 

Aerial views of three nuclear power plants, (a) The Chernobyl nuclear power plant, site of a major nuclear accident in 1986. (b) The Three Mile Island power plant, site of a minor nuclear accident in 1979. (c) A plant in France, which has operated nuclear power plants safely for nearly 30 years. 

Three Mile Island and Chernobyl occurred more than 20 years ago and the nuclear power freeze is beginning to thaw. High priced oil and natural gas make atomic energy appear cheap by comparison. Global-warming concerns are pushing a new interest in nuclear power. After a decade where no nuclear power plants came online in the United States, 31 new reactors are planned. 

Conventional nuclear reactors and advanced breeder reactors were America s primary energy strategy since the 1950s to resolve the fossil fuel problem but when a reactor accident occurred in 1979 at Three Mile Island in Pennsylvania, public and investor confidence in nuclear fission dropped. The accident was triggered by the failure of a feedwater pump that supplied water to the steam generators. The backup feedwater pumps were not connected to the system as required, which caused the reactor to heat up. The safety valve then failed to act which allowed a radioactive water and gas leak. This was the worst nuclear power accident in the U.S., but in this accident no one was killed and no one was directly injured. At Three Mile Island faulty instrumentation gave incorrect readings for the... 

Highly publicized nuclear accidents such as those that occurred at Chernobyl and Three Mile Island must be considered anomalies. Nuclear power plants have multiple safety measures in place to prevent radiation leaks. The small amount of radioactive waste produced by nuclear reactors is controlled and usually contained in the plant facility. 

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). 

There were several root causes for the Three Mile Island Nuclear Power Plant incident that occurred in March 1979.Inadequate follow-up to... 

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. 

The process at Three Mile Island involved nuclear fission and subsequent reactor cooling using circulating water. The primary water was kept under pressure to prevent boiling. Heat was transferred to a secondary water system that supplied power to a steam generator. Upon completion of this step, steam condensate was recovered and recycled. All radioactive materials, including primary water, were enclosed in a lined concrete containment building to prevent their escape to the atmosphere. 

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 accident at unit II of the two pressurized-water nuclear power stations at Three Mile Island (located outside the town of Middletown, Pennsylvania, USA) occurred only three months after starting the commercial production of elec-... 

The devastating accidents at the Chernobyl and Three Mile Island nuclear power plants both occurred as a result of erroneous decisions made between the hours of midnight and 3 00 a.m. 

However, there are problems. The main problem associated with a nuclear power station is that the reactor produces highly radioactive waste materials. These waste materials are difficult to store and cannot be disposed of very easily. Also, leaks of radioactive material have occurred at various sites throughout the world. Accidents at a small number of nuclear power stations, such as Three Mile Island in the US (1979) and Chernobyl in the Ukraine (1986) have led to a great deal of concern about their safety. More recently, in March 2011 a major nuclear accident happened at the Fukushima nuclear power plant in northern Japan. On this occasion the accident was not caused as a result of the plant itself undergoing a problem, but as a result of an earthquake near Japan that gave rise to a tsunami. This damaged essential... 

By the 1970s, nuclear power was in widespread use, in the U S. and abroad, as a source of electricity. As of 2007, nuclear power provided about 19.3% of the electricity generated in the U.S., created by 104 licensed nuclear reactors. Nonetheless, the potential for accidents, meltdowns and other disasters has never been far from the minds of many consumers (after all, for many of us the first image that comes to mind upon hearing the word nuclear is a nuclear bomb). The 1979 Three Mile Island nuclear power plant accident in the U.S. led to the cancellation of scores of nuclear projects across the nation. This trend was later reinforced by the disaster at... 

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... 

Politicians in our parliamentary democracies who wish to please public opinion feel the urge to take into account demands that are more emotional than scientific, and advocate restrictions even when these go against the best interests of the citizens. The Three Mile Island nuclear power plant accident in the United States which resulted in no fatalities, the more recent Chernobyl explosion which, as of 1988 had directly caused two deaths, have, with no good reason, prevented any resumption of the U.S. nuclear program and have aroused fears in European countries in people least likely to give way to mass hysteria. 

---