United States nuclear power plants

Many dozens of industrialized countries now employ nuclear reactors for power generation, and some countries produce more electrical power by nuclear reaction than by fossil fuel combustion (France is an example). The United States, however, has the largest installed capacity of nuclear-powered boiler plants (in the year 2000 there are more than 120 nuclear reactor power plants in the United States). Nuclear power is also widely used for marine duty in both commercial and naval vessels. 

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. 

Nuclear power plants provide about 17% of the world s electricity. There are 400 nuclear power plants around the world, with more than 25% in the United States. France depends more than most countries on nuclear power for electricity, generating about 75% of its electricity from nuclear power. In the United States, nuclear power supplies about 15% of the electricity. 

Nucleai energy is a principal contributor to the production of the world s electricity. As shown in Table 1, many countries are strongly dependent on nuclear energy. For some countries, more than half of the electricity is generated by nuclear means (1,3). There were 424 nuclear power plants operating worldwide as of 1995. Over 100 of these plants contributed over 20% of the electricity in the United States (see also Power generation). 

If possible comparisons are focused on energy systems, nuclear power safety is also estimated to be superior to all electricity generation methods except for natural gas (30). Figure 3 is a plot of that comparison in terms of estimated total deaths to workers and the pubHc and includes deaths associated with secondary processes in the entire fuel cycle. The poorer safety record of the alternatives to nuclear power can be attributed to fataUties in transportation, where comparatively enormous amounts of fossil fuel transport are involved. Continuous or daily refueling of fossil fuel plants is required as compared to refueling a nuclear plant from a few tmckloads only once over a period of one to two years. This disadvantage appHes to solar and wind as well because of the necessary assumption that their backup power in periods of no or Httie wind or sun is from fossil-fuel generation. Now death or serious injury has resulted from radiation exposure from commercial nuclear power plants in the United States (31). 

In 1980, Congress deterrnined that each state should be responsible for ensuring the proper handling and disposal of commercial low level nuclear wastes generated in their states. Regional disposal sites have also been estabHshed at BamweU, South Carolina, and Ward Valley, California. These wastes are handled by Hcensed disposal faciHties where they are packaged, placed in burial trenches, and covered with soil. Less than half of the low level nuclear waste produced annually in the United States comes from nuclear power plants. Low level nuclear power plant wastes include contaminated equipment. 

The largest consumers of water in the United States are thermal power plants (eg, steam and nuclear power plants) and the iron and steel, pulp and paper, petroleum refining, and food-processing industries. They consume >60% of the total industrial water requirements (see also Power generation Wastes, industrial). 

Swain, A. D., and H. E. Guttmann (1983). Handbook of Human Reliability Analysis With Emphasis on Nuclear Power Plant Applications. NUREG/ CR-1278. Washington, DC United States Nuclear Regulatory Commission. 

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. 

Last new nuclear power plant ordered in the United States. 

Nuclear fission accounted for 13 percent of the electricity generated in the United States in 1985. Plants under construction in 1985 will probably raise the proportion to 20 percent by 1993. However, overexpansion of electrical generating capacity in this country, actual and imagined hazards of nuclear power plants, and negative perceptions of nuclear power by the public have combined to halt commitments to build new plants. New constmction is not expected to resume before the 1990s. 

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. 

The Electric Power Research Institute (EPRI 1981) conducted a survey of transuranic radionuclides in the terrestrial environs of nuclear power plants in the United States in 1978-1979. The plants included two pressurized water reactors (PWRs) and two BWRs that were of modem design and had been in operation at least 3 years. The 241 Am air concentrations around all of the power plants were extremely low and indistinguishable from fallout background... 

Information is available on the levels of241 Am in soil and sediment in areas affected only by global fallout, at DOE installations and other nuclear facilities, as well as sites of nuclear explosions and accidents (Alberts et al. 1989 Bennett 1979 Cooper et al. 1994 DOE 1980 Pattenden and McKay 1994 Robison et al. 1997a, 1997b Sanchez et al. 1996). 241Am levels in soil around nuclear power plants in the United States were indistinguishable from fallout background (EPRI 1981). 

An Important difference is In the use of materials which in Prance la only about 2/3 of the United States. Hven greater is the difference of the amount of labor Involved which in France is only about 1/3 of the United States. A still greater ratio exists in the number of engineers and draftsmen required. One reason for that le that a larger fraction of the design la done in the home office rather than in the field. In the United States in 1967 about 3.3 million man hours were required to build a nuclear power plant in 1983 this number had gone up to 30 million man lioura. Field services in the U.S. went from 1.3 to 22 million man hours. 

There is now a marked pause in the construction and deployment of new nuclear power plants. Although some construction of reactors continues in Asia and Eastern Europe, a de facto moratorium exists in the United States and in most of Europe, while in Sweden and Gennany the governments plan to shut down operating plants before the end of their normal lifetimes. The inhibitions on nuclear power development stem in large measure from environmental concerns, particularly concerns relating to reactor accidents and nuclear wastes. 

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. 

The current proven coal reserves of the United States are predicted to support this production level for 200 years. This liquefied coal reserve exceeds the proven oil reserves of the entire world. The reactors could also produce hydrogen or gaseous hydrocarbons from the coal as well. The excess heat from nuclear power plants could be used for central heating. 

Our exposure to man-made radioactive sources, such as from nuclear power plants, is negligible when compared to the total radiation we receive. Man-made radiation accounts for less than 3% of the total radiation we receive in the United States, but in some countries, this figure is higher. The vast majority of the 3% of man-made doses of radiation we receive in our lifetime results from medical uses, and the vast majority of the 97% of the total exposure to all radiation we receive comes from natural sources. 

The volume of nuclear wastes produced is relatively small compared with the volume of municipal solid wastes and industrial wastes and is very much less than that of agricultural and mining wastes. Each year, for example, the 104 nuclear power plants now operating in the United States generate a total of about 30,000 short tons (27,000 metric tons) of nuclear waste. That volume is about 0.001 percent the amount of hazardous wastes produced every year. In the five decades that nuclear power plants have been operating in the United States, a total of about 9,000 short tons (8,200 metric... 

As of March 2003, there were 26 spent fuel storage facilities in the United States located in 21 states. A total of about 160,000 spent fuel units containing about 45,000 short tons (41,000 metric tons) of radioactive waste were stored on-site at nuclear power plants and off-site at special storage areas. More than 97 percent of the wastes were still being held at on-site facilities the rest had been transported to off-site locations. 

---