Nuclear power plants Chernobyl accident

Nuclear activities such as electricity production by nuclear power plants, or accidents such as occurred at Chernobyl, release radionulides, including caesium, into the environment. The caesium concentrations in these matrices is very low, so that in addition to a sensitive analytical method, it is necessary to make use of an enrichment technique to bring the caesium concentration within the scope of the analytical method. 

Experience from the 1986 Chernobyl reactor accident in the Ukraine shows the potential magnitude and impact of a terrorist attack on a nuclear power plant. The accident involved an explosion in a reactor that releases very high levels of radiation for miles surrounding the reactor site. Low levels of radiation were spread by wind currents throughout Europe and the rest of the world. According to Caldicott 2002,... 

Eisler, R. 2003. The Chernobyl nuclear power plant reactor accident ecotoxicological update. Pages 703-736 in D.J. Hoffman, B.A. Rattner, C.A. Burton, Jr., and J. Cairns, Jr., eds. Handbook of Ecotoxicology, Second Edition. I.ewis I ublishers, Boca Raton, Horida. 

Chernobyl may represent the upper limit that is possible in a nuclear power plant accident. 

Advances in teclmology liai e brought about new problems. Nuclear power plant accidents (Tliree Mile Island and Chernobyl) have been the most frightening, perliaps because no one really knows what to expect from them. 

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 fear of accidents like Chernobyl, and the high cost of nuclear waste disposal, halted nuclear power plant construction in the United States m the 1980s, and in most ol the rest ol the world by the 1990s. Because nuclear fusion does not present the waste disposal problem of fission reactors, there is hope that fusion will be the primary energy source late in the twenty-first centuiy as the supplies of natural gas and petroleum dwindle. 

Half-lives span a very wide range (Table 17.5). Consider strontium-90, for which the half-life is 28 a. This nuclide is present in nuclear fallout, the fine dust that settles from clouds of airborne particles after the explosion of a nuclear bomb, and may also be present in the accidental release of radioactive materials into the air. Because it is chemically very similar to calcium, strontium may accompany that element through the environment and become incorporated into bones once there, it continues to emit radiation for many years. About 10 half-lives (for strontium-90, 280 a) must pass before the activity of a sample has fallen to 1/1000 of its initial value. Iodine-131, which was released in the accidental fire at the Chernobyl nuclear power plant, has a half-life of only 8.05 d, but it accumulates in the thyroid gland. Several cases of thyroid cancer have been linked to iodine-131 exposure from the accident. Plutonium-239 has a half-life of 24 ka (24000 years). Consequently, very long term storage facilities are required for plutonium waste, and land contaminated with plutonium cannot be inhabited again for thousands of years without expensive remediation efforts. 

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. 

The nuclear explosions that devastated Hiroshima and Nagasaki killed 100,000 to 200,000 people instantaneously. Probably an equal number died later, victims of the radiation released in those explosions. Millions of people were exposed to the radioactivity released by the accident at the Chernobyl nuclear power plant. The full health effects of that accident may never be known, but 31 people died of radiation sickness within a few weeks of the accident, and more than 2000 people have developed thyroid cancer through exposure to radioactive iodine released in the accident. Even low levels of radiation can cause health problems. For this reason, workers in facilities that use radioisotopes monitor their exposure to radiation continually, and they must be rotated to other duties if their total exposure exceeds prescribed levels. 

The nuclear power plant accident at Chernobyl in April 1986 (IAEA Technical Report 1991) proved to be a much more potent source of environmental contamination in many surrounding countries, over distances up to several thousands of kilometers, and was a cause of worldwide problems in international trade in food products contaminated (or possibly contaminated) with radionuclides. The resulting requirement by many countries to establish systems for monitoring radionuclides in foodstuffs and in the environment led to a large worldwide increase in the demand for suitable reference materials. 

Although the Chernobyl accident was very serious, the defects in design and operating procedures that led to it were so egregious that the accident has tittle relevance to current reactors outside the former Soviet Union. However, it serves as a reminder of the need for rigorous care in the design, construction, and operation of nuclear power plants. 

Military weapons tests conducted at the Pacific Proving Grounds in the 1940s and 1950s resulted in greatly elevated local concentrations of radionuclides, and an accident at the Chernobyl nuclear power plant in the former Soviet Union in 1986 resulted in comparatively low concentrations of radionuclides dispersed over a wide geographical area. Both cases are briefly reviewed. 

Makeyeva, A.P., N.G. Yemel yanova, N.V. Belova, and I.N. Ryabov. 1995. Radiobiological analysis of silver carp, Hypophthalmichthys molitrix, from the cooling pond of the Chernobyl nuclear power plant since the time of the accident. 2. Development of the reproductive system in the first generation of offspring. Jour. Ichthyol. 35 40-64. 

Environmentally hazardous projects are those where the risk of accidents is very high, which can result in a major and sometimes even catastrophic chemical pollution of the environment. Frequently, these disasters take casualties among the plant personnel, as well as among the nearby settlements population, which were the cases with the Chernobyl Nuclear Power Plant disaster in Ukraine, or with the pesticide plant accident in Bhopal, India. 

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). 

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. 

The 1986 accident at Chernobyl, in which dozens of people died and thousands more were exposed to radiation that might lead to cancer in the future, caused fear and outrage worldwide and led some people to call for the closing of all nuclear plants. Yet many people choose to smoke cigarettes in spite of the fact that 2 million people die every year from smoking-related diseases. The risks posed by nuclear power plants are involuntary, risks we must all share like it or not,... 

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... 

Radioactive substances The principal sources of radionuclides released into the environment include nuclear weapon testing fallout from accidents such as the Chernobyl accident in 1986 or from foundering of nuclear submarines from the dumping of nuclear waste into the deep ocean and from discharges from nuclear power plants and nuclear reprocessing plants. 

U.S.S.R. State Committee on the Utilization of Atomic Energy (1986) The accident at the Chernobyl nuclear power plant and its consequences. Safety Series No. 75-INSAG-I. IAEA, Vienna. 

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. 

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. 

Chernobyl Nuclear Power Plant Accident-Health and Environmental Consequences, DOE/ER-0332 US Department of Energy, June 1987. 

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