Nuclear Energy

Nuclear power is not renewable, but some view it as an alternative to fossil fuels. The big advantage of nuclear power is the large amount of energy released from a small amount of material. One kilogram of enriched nuclear fuel contains more than 2 million times the energy in 1 kilogram of coal. However, nuclear power presents serious challenges.

Distribution of Nuclear Power

Nuclear power supplies 14 percent of the world’s electricity. Two-thirds of the world’s nuclear power is generated in developed countries, with Europe and North America responsible for generating one-third each. Only 30 of the world’s nearly 200 countries make some use of nuclear power, including 19 developed countries and only 11 developing countries. The countries most highly dependent on nuclear power are clustered in Europe (Figure 11-45), where it supplies 80 percent of all electricity in France and more than 50 percent in Belgium, Slovakia, and Ukraine.

Electricity from Nuclear Power

Dependency on nuclear power varies widely among U.S. states. Nuclear power accounts for more than 70 percent of electricity in Vermont and more than one-half in Connecticut, New Jersey, and South Carolina. At the other extreme, 20 states and the District of Columbia have no nuclear power plants.

Nuclear Power by U.S. State

Potential Accidents

A nuclear power plant produces electricity from energy released by splitting uranium atoms in a controlled environment, a process called fission. One product of all nuclear reactions is radioactive waste, certain types of which are lethal to people exposed to it. Elaborate safety precautions are taken to prevent the leaking of nuclear fuel from a power plant.

Nuclear power plants cannot explode, like a nuclear bomb, because the quantities of uranium are too small and cannot be brought together fast enough. However, it is possible to have a runaway reaction, which overheats the reactor, causing a meltdown, possible steam explosions, and scattering of radioactive material into the atmosphere. This happened in 1986 at Chernobyl, then in the Soviet Union and now in the north of Ukraine, near the Belarus border. The accident caused 56 deaths due to exposure to high radiation doses and an estimated 4,000 cancer-related deaths to people who lived near the plant.

Following an earthquake and tsunami in 2011, three of the six reactors at Japan’s Fukushima Daiichi nuclear power plant experienced full meltdown, resulting in release of radioactive materials. Three workers died; the death toll among nearby residents exposed to high levels of radioactivity won’t be known for years.

Radioactive Waste

The waste from nuclear fission is highly radioactive and lethal, and it remains so for many years. Plutonium for making nuclear weapons can be harvested from this waste. Pipes, concrete, and water near the fissioning fuel also become “hot” with radioactivity. No one has yet devised permanent storage for radioactive waste. The waste cannot be burned or chemically treated, and it must be isolated for several thousand years until it loses its radioactivity.

The United States is Earth’s third-largest country in land area, yet it has failed to find a suitable underground storage site because of political opposition and worry about groundwater contamination. The U.S. Department of Energy approved a plan to store the waste in Nevada’s Yucca Mountains in 2002, but federal funding for the project ended in 2011, following intense public opposition. In the meantime, most U.S. nuclear power plants are storing radioactive waste in “temporary” steel and concrete casks. Some waste is being stored at the Waste Isolation Pilot Plant 660 meters (2,150 feet) below the surface in New Mexico.

Bomb Material

The world has eight acknowledged nuclear powers, as discussed in Chapter 8. The diffusion of nuclear programs to countries sympathetic to terrorists has been particularly worrying to the rest of the world and has been a major factor in long-time tensions between Iran and other countries that do not want Iran to gain the capability of building a nuclear weapon.

Limited Reserves

Like fossil fuels, uranium is a nonrenewable resource. Proven uranium reserves will last about 124 years at current rates of use. And they are not distributed uniformly around the world: Australia has 29 percent of the world’s proven uranium reserves, Kazakhstan 13 percent, and Canada and Russia 9 percent each.

World Uranium Reserves

The chemical composition of natural uranium further aggravates the scarcity problem. Uranium ore naturally contains only 0.7 percent U-235; a greater concentration is needed for power generation. A breeder reactor turns uranium into a renewable resource by generating plutonium, also a nuclear fuel. However, plutonium is more lethal than uranium and could cause more deaths and injuries in an accident. It is also easier to fashion into a bomb. Because of these risks, few breeder reactors have been built, and none are in the United States.

High Cost

Nuclear power plants cost several billion dollars to build, primarily because of the elaborate safety measures required. Without double and triple backup systems at nuclear power plants, nuclear energy would be too dangerous to use. Uranium is mined in one place, refined in another, and used in still another. As with coal, mining uranium can pollute land and water and damage miners’ health. The complexities of safe transportation add to the cost. As a result, generating electricity from nuclear plants is much more expensive than from coal-burning plants. The future of nuclear power has been seriously hurt by the high costs associated with reducing risks.

Nuclear Power Plant

Indian Point Energy Center, Buchanan, New York, is slated for closure because of environmental concerns.

Some nuclear power issues might be addressed through nuclear fusion, which is the fusing of hydrogen atoms to form helium. Fusion can occur only at very high temperatures (millions of degrees) that cannot be generated on a sustained basis in a power-plant reactor with current technology.

Pause & Reflect 11.2.5

Should dependency on nuclear energy be increased or decreased? Why?