1. Nonrenewable Energy
Chapter 15

2. Core Case Study: How Long Will Supplies of Conventional Oil Last?
Oil: energy supplier
How much is left? When will we run out?
Three options
Look for more
Reduce oil use and waste
Use other energy sources
No easy solutions

3. Thunder Horse Offshore Floating Oil Production Platform in the Gulf of Mexico

4. 15-1 What Major Sources of Energy Do We Use?
Concept 15-1A About three-quarters of the world’s commercial energy comes from nonrenewable fossil fuels and the rest comes from nonrenewable nuclear fuel and renewable sources.
Concept 15-1B Net energy is the amount of high-quality usable energy available from a resource after the amount of energy needed to make it available is subtracted.

5. Fossil Fuels Supply Most of Our Commercial Energy
Solar energy
Indirect solar energy
Wind
Hydropower
Biomass
Commercial energy
Nonrenewable energy resources, e.g. fossil fuels
Renewable energy resources

6. Natural Capital: Important Nonrenewable Energy Resources

7. Geothermal energy Underground coal mine
Oil and natural gas
Oil storage
Coal
Contour strip mining
Geothermal energy
Oil drilling platform
Hot water storage
Geothermal power plant
Oil well
Pipeline
Gas well
Mined coal
Pipeline
Pump
Area strip mining
Drilling tower
Underground coal mine
Impervious rock
Water
Oil
Natural gas
Figure 15.2
Natural capital: important nonrenewable energy resources that can be removed from the earth’s crust are coal, oil, natural gas, and some forms of geothermal energy (Concept 15-1A). Nonrenewable uranium ore is also extracted from the earth’s crust and processed to increase its concentration of uranium-235, which serves as a fuel in nuclear reactors that produce electricity. Question: During a typical day, which of these resources do you use directly or indirectly?
Water is heated and brought up as dry steam or wet steam
Water
Coal seam
Hot rock
Water penetrates down through the rock
Magma
Fig. 15-2, p. 372

8. Commercial Energy Use by Source for the World and the United States

9. Geothermal, solar, wind 2.5% Nuclear power 8%
Hydropower 4.5%
Hydropower, 3%
Natural gas 23%
Natural gas 21%
RENEWABLE 18%
Biomass 11%
Coal 23%
Biomass 3%
RENEWABLE 7%
Coal 22%
Oil 39%
Oil 33%
NONRENEWABLE 82%
NONRENEWABLE 93%
Figure 15.3
Commercial energy use by source for the world (left) and the United States (right) Question: Why do you think the world as a whole relies more on renewable energy than the United States does? (Data from U.S. Department of Energy, British Petroleum, Worldwatch Institute, and International Energy Agency)
World
United States
Fig. 15-3, p. 373

10. Case Study: A Brief History of Human Energy Use
Muscle power: early humans
Discovery of fire
Agriculture
Use of wind and flowing water
Machines powered by wood, then coal
Internal combustion engine
Nuclear energy
Energy crisis

11. How Should We Evaluate Energy Resources?
Supplies
Environmental impact
How much useful energy is provided?

12. Science Focus: Net Energy Is the Only Energy That Really Counts
It takes energy to get energy
Second Law of Thermodynamics
Net energy expressed as net energy ratio
Conventional oil: high net energy ratio
Electricity produced by the nuclear power fuel cycle: low net energy ratio

13. Net Energy Ratios for Various Energy Systems over Their Estimated Lifetimes

14. Figure 15.A
Science: Net energy ratios for various energy systems over their estimated lifetimes: the higher the net energy ratio, the greater the net energy available (Concept 15-1B). A useful rule of thumb is that any energy resource with a low net energy will need government (taxpayer) subsidies to compete in the marketplace with high net energy resources. In other words, subsidies and tax breaks must be used to keep its price artificially low. Question: Based on these data, which two resources in each category should we be using? Compare this with the major resources we are actually using as shown in Figure (Data from U.S. Department of Energy, U.S. Department of Agriculture, Colorado Energy Research Institute, Net Energy Analysis, 1976; and Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981)
Fig. 15-A (1), p. 374

15. Electric heating (coal-fired plant) 0.4
Space Heating
Passive solar
5.8
Natural gas
4.9
Oil
4.5
Active solar
1.9
Coal gasification
1.5
Electric heating (coal-fired plant)
0.4
Figure 15.A
Science: Net energy ratios for various energy systems over their estimated lifetimes: the higher the net energy ratio, the greater the net energy available (Concept 15-1B). A useful rule of thumb is that any energy resource with a low net energy will need government (taxpayer) subsidies to compete in the marketplace with high net energy resources. In other words, subsidies and tax breaks must be used to keep its price artificially low. Question: Based on these data, which two resources in each category should we be using? Compare this with the major resources we are actually using as shown in Figure (Data from U.S. Department of Energy, U.S. Department of Agriculture, Colorado Energy Research Institute, Net Energy Analysis, 1976; and Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981)
Electric heating
(natural-gas-fired plant)
0.4
Electric heating (nuclear plant)
0.3
Fig. 15-A (1), p. 374

16. Figure 15.A
Science: Net energy ratios for various energy systems over their estimated lifetimes: the higher the net energy ratio, the greater the net energy available (Concept 15-1B). A useful rule of thumb is that any energy resource with a low net energy will need government (taxpayer) subsidies to compete in the marketplace with high net energy resources. In other words, subsidies and tax breaks must be used to keep its price artificially low. Question: Based on these data, which two resources in each category should we be using? Compare this with the major resources we are actually using as shown in Figure (Data from U.S. Department of Energy, U.S. Department of Agriculture, Colorado Energy Research Institute, Net Energy Analysis, 1976; and Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981)
Fig. 15-A (2), p. 374

17. High-Temperature Industrial Heat
Surface-mined coal
28.2
Underground-mined coal
25.8
Natural gas
4.9
Oil
4.7
Coal gasification
1.5
Direct solar (concentrated)
0.9
Figure 15.A
Science: Net energy ratios for various energy systems over their estimated lifetimes: the higher the net energy ratio, the greater the net energy available (Concept 15-1B). A useful rule of thumb is that any energy resource with a low net energy will need government (taxpayer) subsidies to compete in the marketplace with high net energy resources. In other words, subsidies and tax breaks must be used to keep its price artificially low. Question: Based on these data, which two resources in each category should we be using? Compare this with the major resources we are actually using as shown in Figure (Data from U.S. Department of Energy, U.S. Department of Agriculture, Colorado Energy Research Institute, Net Energy Analysis, 1976; and Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981)
Fig. 15-A (2), p. 374

18. Figure 15.A
Science: Net energy ratios for various energy systems over their estimated lifetimes: the higher the net energy ratio, the greater the net energy available (Concept 15-1B). A useful rule of thumb is that any energy resource with a low net energy will need government (taxpayer) subsidies to compete in the marketplace with high net energy resources. In other words, subsidies and tax breaks must be used to keep its price artificially low. Question: Based on these data, which two resources in each category should we be using? Compare this with the major resources we are actually using as shown in Figure (Data from U.S. Department of Energy, U.S. Department of Agriculture, Colorado Energy Research Institute, Net Energy Analysis, 1976; and Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981)
Fig. 15-A (3), p. 374

19. Ethanol from sugarcane residue 8.0
Transportation
Ethanol from sugarcane residue
8.0
Ethanol from switchgrass
5.4
Natural gas
4.9
Gasoline (refined crude oil)
4.1
Coal liquefaction
1.4
Figure 15.A
Science: Net energy ratios for various energy systems over their estimated lifetimes: the higher the net energy ratio, the greater the net energy available (Concept 15-1B). A useful rule of thumb is that any energy resource with a low net energy will need government (taxpayer) subsidies to compete in the marketplace with high net energy resources. In other words, subsidies and tax breaks must be used to keep its price artificially low. Question: Based on these data, which two resources in each category should we be using? Compare this with the major resources we are actually using as shown in Figure (Data from U.S. Department of Energy, U.S. Department of Agriculture, Colorado Energy Research Institute, Net Energy Analysis, 1976; and Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981)
Oil shale
1.2
Ethanol from corn
1.1 (but can reach 1.5)
Fig. 15-A (3), p. 374

20. Electric heating (coal-fired plant) 0.4
Space Heating
Passive solar
5.8
Natural gas
4.9
Oil
4.5
Active solar
1.9
Coal gasification
1.5
Electric heating (coal-fired plant)
0.4
Electric heating (natural-gas-fired plant)
Electric heating (nuclear plant)
0.3
High-Temperature Industrial Heat
Surface-mined coal
28.2
Underground-mined coal
25.8
Natural gas
4.9
Oil
4.7
Coal gasification
1.5
Direct solar (concentrated)
0.9
Figure 15.A
Science: Net energy ratios for various energy systems over their estimated lifetimes: the higher the net energy ratio, the greater the net energy available (Concept 15-1B). A useful rule of thumb is that any energy resource with a low net energy will need government (taxpayer) subsidies to compete in the marketplace with high net energy resources. In other words, subsidies and tax breaks must be used to keep its price artificially low. Question: Based on these data, which two resources in each category should we be using? Compare this with the major resources we are actually using as shown in Figure (Data from U.S. Department of Energy, U.S. Department of Agriculture, Colorado Energy Research Institute, Net Energy Analysis, 1976; and Howard T. Odum and Elisabeth C. Odum, Energy Basis for Man and Nature, 3rd ed., New York: McGraw-Hill, 1981)
Transportation
Ethanol from sugarcane residue
8.0
Ethanol from switchgrass
5.4
Natural gas
4.9
Gasoline (refined crude oil)
4.1
Coal liquefaction
1.4
Oil shale
1.2
Ethanol from corn
1.1 (but can reach 1.5)
Stepped Art
Fig. 15-A, p. 374

21. Animation: Energy use

22. 15-2 What Are the Advantages and Disadvantages of Oil?
Concept 15-2A Conventional oil is currently abundant, has a high net energy yield, and is relatively inexpensive, but using it causes air and water pollution and releases greenhouse gases to the atmosphere.
Concept 15-2B Heavy oils from oil sand and oil shale exist in potentially large supplies but have low net energy yields and higher environmental impacts than conventional oil has.

23. We Depend Heavily on Oil
Petroleum, or crude oil = conventional, or light oil
Fossil fuels: crude oil and natural gas
Oil extraction and refining
Petrochemicals: products of oil distillation
World oil consumption

24. Science: Refining Crude Oil

25. Figure 15.4
Science: refining crude oil. Components of petroleum are removed at various levels, depending on their boiling points, in a giant distillation column. The most volatile components with the lowest boiling points are removed at the top of the column. The photo shows an oil refinery in the U.S. state of Texas.
Fig. 15-4a, p. 375

26. Lowest Boiling Point Gases Gasoline Aviation fuel Heating oil
Diesel oil
Naphtha
Figure 15.4
Science: refining crude oil. Components of petroleum are removed at various levels, depending on their boiling points, in a giant distillation column. The most volatile components with the lowest boiling points are removed at the top of the column. The photo shows an oil refinery in the U.S. state of Texas.
Grease and wax
Heated crude oil
Asphalt
Furnace
Highest Boiling Point
Fig. 15-4a, p. 375

27. Figure 15.4
Science: refining crude oil. Components of petroleum are removed at various levels, depending on their boiling points, in a giant distillation column. The most volatile components with the lowest boiling points are removed at the top of the column. The photo shows an oil refinery in the U.S. state of Texas.
Fig. 15-4b, p. 375

28. OPEC Controls Most of the World’s Oil Supplies (1)
13 countries have at least 60% of the world’s crude oil reserves
Saudi Arabia: 25%
Canada: 15%
Oil production peaks and flow rates to consumers

29. OPEC Controls Most of the World’s Oil Supplies (2)
Possible effects of steeply rising oil prices
Reduce energy waste
Shift to non-carbon energy sources
Higher prices for products made with petrochemicals
Higher food prices; buy locally-produced food
Airfares higher
Smaller more fuel-efficient vehicles
Upgrade of public transportation

30. The United States Uses Much More Oil Than It Produces (1)
Produces 9% of the world’s oil
Imports 60% of its oil
About One-fourth of the world’s conventional oil is controlled by countries that sponsor or condone terrorism

31. The United States Uses Much More Oil Than It Produces (2)
Should we look for more oil reserves?
Extremely difficult
Expensive and financially risky
A new role for bacteria in the oil industry 31

32. Case Study: Oil and the U.S. Arctic National Wildlife Refuge
The Arctic National Wildlife Refuge (ANWR)
Not open to oil and gas development
Fragile tundra biome
Oil companies lobbying since 1980 to begin exploratory drilling
Pros
Cons

33. The Amount of Oil That Might Be Found in the ANWR

34. Projected U.S. oil consumption14 13 12 11 10
Projected U.S. oil consumption 9
Barrels of oil per year (billions) 8 7 6 5 4
Figure 15.5
The amount of oil that might be found in the Arctic National Wildlife Refuge, if developed and extracted over 50 years, is only a tiny fraction of projected U.S. oil consumption. (Data from U.S. Department of Energy, U.S. Geological Survey, and Natural Resources Defense Council) 3
Arctic refuge oil output over 50 years 2 1
2000
2010
2020
2030
2040
2050
Year
Fig. 15-5, p. 378

35. Conventional Oil Has Advantages and Disadvantages
Extraction, processing, and burning of nonrenewable oil and other fossil fuels
Advantages
Disadvantages

36. Trade-Offs: Conventional Oil, Advantages and Disadvantages

37. TRADE-OFFS Conventional Oil Advantages Disadvantages
Ample supply for 42–93 years
Need to find substitutes within 50 years
Low cost
Large government subsidies
High net energy yield
Environmental costs not included in market price
Easily transported within and between countries
Artificially low price encourages waste and discourages search for alternatives
Figure 15.6
Advantages and disadvantages of using conventional crude oil as an energy resource (Concept 15-2A). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Low land use
Pollutes air when produced and burned
Technology is well developed
Releases CO2 when burned
Efficient distribution system
Can cause water pollution
Fig. 15-6, p. 379

38. Bird Covered with Oil from an Oil Spill in Brazilian Waters

39. Will Heavy Oil Spills from Oil Sand Be a Viable Option?
Oil sand, tar sand contains bitumen
Canada and Venezuela: oil sand have more oil than in Saudi Arabia
Extraction
Serious environmental impact before strip-mining
Low net energy yield: Is it cost effective?

40. Will Oil Shales Be a Useable Resource?
Oil shales contain kerogen
After distillation: shale oil
72% of the world’s reserve is in arid areas of western United States; there is a catch!
Locked up in rock
Lack of water needed for extraction and processing
Low net energy yield

41. Oil Shale Rock and the Shale Oil Extracted from It

42. Trade-Offs: Heavy Oils from Oil Shale and Oil Sand

43. TRADE-OFFS Heavy Oils from Oil Shale and Oil Sand Advantages
Disadvantages
Moderate cost (oil sand)
High cost (oil shale)
Low net energy yield
Large potential supplies, especially oil sands in Canada
Environmental costs not included in market price
Easily transported within and between countries
Large amounts of water needed for processing
Figure 15.9
Advantages and disadvantages of using heavy oils from oil sand and oil shale as energy resources (Concept 15-2B). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Severe land disruption
Efficient distribution system in place
Severe water pollution
Technology well-developed (oil sand)
Air pollution and CO2 emissions when produced and burned
Fig. 15-9, p. 380

44. 15-3 What Are the Advantages and Disadvantages of Natural Gas?
Concept Conventional natural gas is more plentiful than oil, has a high net energy yield and a fairly low cost, and has the lowest environmental impact of all fossil fuels.

45. Natural Gas Is a Useful and Clean-Burning Fossil Fuel (1)
Natural gas: mixture of gases
More than half is CH4
Conventional natural gas
Pipelines
Liquefied petroleum gas (LPG)
Liquefied natural gas (LNG) – low net energy yield

46. Natural Gas Is a Useful and Clean-Burning Fossil Fuel (2)
Unconventional natural gas
Coal bed methane gas
Methane hydrate

47. Natural Gas Has More Advantages Than Disadvantages
Will natural gas be the bridge fuel helping us make the transition to a more sustainable energy future?

48. Trade-Offs: Conventional Natural Gas

49. TRADE-OFFS Conventional Natural Gas Advantages Disadvantages
Ample supplies
Nonrenewable resource
High net energy yield
Releases CO2 when burned
Low cost
Gas turbine
Government subsidies
Less air pollution than other fossil fuels
Environmental costs not included in market price
Lower CO2 emissions than other fossil fuels
Methane (a greenhouse gas) can leak from pipelines
Figure 15.10
Advantages and disadvantages of using conventional natural gas as an energy resource (Concept 15-3). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Easily transported by pipeline
Difficult to transfer from one country to another
Low land use
Good fuel for fuel cells, gas turbines, and motor vehicles
Can be shipped across ocean only as highly explosive LNG
Fig , p. 382

50. 15-4 What Are the Advantages and Disadvantages of Coal?
Concept 15-4A Conventional coal is very plentiful and has a high net energy yield and low cost, but it has a very high environmental impact.
Concept 15-4B Gaseous and liquid fuels produced from coal could be plentiful, but they have lower net energy yields and higher environmental impacts than conventional coal has.

51. Coal Comes in Several Forms and Is Burned Mostly to Produce Electricity
Coal: solid fossil fuel
Burned in 2100 power plants, generates 40% of the world’s electricity
Inefficient
Three largest coal-burning countries
China
United States
Canada

52. Stages in Coal Formation over Millions of Years

53. Increasing heat and carbon content Increasing moisture content Peat
(not a coal)
Lignite
(brown coal)
Bituminous
(soft coal)
Anthracite
(hard coal)
Heat
Heat
Heat
Pressure
Pressure
Pressure
Partially decayed plant matter in swamps and bogs; low heat content
Low heat content; low sulfur content; limited supplies in most areas
Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content
Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas
Figure 15.11
Stages in coal formation over millions of years. Peat is a soil material made of moist, partially decomposed organic matter and is not classified as a coal, although it too is used as a fuel. The different major types of coal vary in the amounts of heat, carbon dioxide, and sulfur dioxide released per unit of mass when they are burned.
Fig , p. 383

54. Increasing moisture content Increasing heat and carbon content
Peat
(not a coal)
Lignite
(brown coal)
Bituminous
(soft coal)
Anthracite
(hard coal)
Heat
Pressure
Partially decayed plant matter in swamps and bogs; low heat content
Low heat content; low sulfur content; limited supplies in most areas
Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content
Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas
Figure 15.11
Stages in coal formation over millions of years. Peat is a soil material made of moist, partially decomposed organic matter and is not classified as a coal, although it too is used as a fuel. The different major types of coal vary in the amounts of heat, carbon dioxide, and sulfur dioxide released per unit of mass when they are burned.
Stepped Art
Fig , p. 383

55. Science: Coal-Burning Power Plant

56. Cooling tower transfers waste heat to atmosphere
Coal bunker
Turbine
Cooling tower transfers waste heat to atmosphere
Generator
Cooling loop
Stack
Figure 15.12
Science: coal-burning power plant. Heat produced by burning pulverized coal in a furnace boils water to produce steam that spins a turbine to produce electricity. The steam is cooled, condensed, and returned to the boiler for reuse. Waste heat can be transferred to the atmosphere or to a nearby source of water. Water is pumped through a condenser and back to the water source to remove the waste heat. The largest coal-burning power plant in the United States is in Indiana. It burns 23 metric tons (25 tons) of coal per minute, or three 100-car trainloads of coal per day. The photo shows a coal-burning power plant in Soto de Ribera, Spain. Question: Does the electricity that you use come from a coal-burning power plant?
Pulverizing mill
Condenser
Filter
Boiler
Toxic ash disposal
Fig , p. 383

57. Coal Is a Plentiful but Dirty Fuel (1)
World’s most abundant fossil fuel
U.S. has 25%
Environmental costs of burning coal
Severe air pollution
Sulfur released as SO2
Large amount of soot
CO2
Trace amounts of Hg and radioactive materials

58. Coal Is a Plentiful but Dirty Fuel (2)
Environmentalists call for
Taxation on CO2 production by power plants
Cleaner coal-burning plants

59. Air Pollution from a Coal-Burning Industrial Plant in India

60. CO2 Emissions Per Unit of Electrical Energy Produced for Energy Sources

61. Coal-fired electricity 286%
Synthetic oil and gas produced from coal
150%
Coal
100%
Oil sand
92%
Oil
86%
Figure 15.14
CO2 emissions per unit of electrical energy produced for various energy resources, expressed as percentages of emissions released by burning coal directly. These emissions can enhance the earth’s natural greenhouse effect (Figure 3-8, p. 56) and promote climate change (Concept 15-4A). Question: Which produces more CO2 emissions: burning coal to heat a house, or heating with electricity generated by coal? (Data from U.S. Department of Energy)
Natural gas
58%
Nuclear power fuel cycle
17%
Geothermal
10%
Fig , p. 384

62. Coal-fired electricity 286%
Synthetic oil and gas produced from coal
150%
Coal
100%
Oil sand
92%
Oil
86%
Natural gas
58%
Figure 15.14
CO2 emissions per unit of electrical energy produced for various energy resources, expressed as percentages of emissions released by burning coal directly. These emissions can enhance the earth’s natural greenhouse effect (Figure 3-8, p. 56) and promote climate change (Concept 15-4A). Question: Which produces more CO2 emissions: burning coal to heat a house, or heating with electricity generated by coal? (Data from U.S. Department of Energy)
Nuclear power fuel cycle
17%
Geothermal
10%
Stepped Art
Fig , p. 384

63. Case Study: Coal Consumption in China
Burns more coal than the United States, Europe, and Japan combined
Coal–burning plants: Inefficient or non-existent pollution controls
Leading area for SO2 pollution: health hazard
Acid rain due to coal burning
Hg showing up in salmon off the western coast of the United States
Air quality of Korea and Japan impacted

64. Coal Has Advantages and Disadvantages
Single biggest air polluter in coal-burning countries
One-fourth of the annul CO2 emissions
Many opposed to new coal-burning power plants
Advantages
Disadvantages

65. Trade-Offs: Coal, Advantages and Disadvantages as an Energy Resource

66. TRADE-OFFS Coal Advantages Disadvantages
Ample supplies (225–900 years)
Severe land disturbance, air pollution, and water pollution
High net energy yield
Severe threat to human health when burned
Environmental costs not included in market price
Low cost
Large government subsidies
Figure 15.15
Advantages and disadvantages of using coal as an energy resource (Concept 15-4A). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Well-developed technology
High CO2 emissions when produced and burned
Air pollution can be reduced with improved technology
Radioactive particle and toxic mercury emissions
Fig , p. 385

67. We Can Convert Coal into Gaseous and Liquid Fuels
Conversion of solid coal to
Synthetic natural gas (SNG) by coal gasification
Methanol or synthetic gasoline by coal liquefaction
Are there benefits to using these synthetic fuels?

68. Trade-Offs: Synthetic Fuels

69. TRADE-OFFS Synthetic fuels Advantages Disadvantages
Large potential supply
Low to moderate net energy yield
Higher cost than coal
Requires mining 50% more coal
Vehicle fuel
Environmental costs not included in market price
Figure 15.16
Advantages and disadvantages of using synthetic natural gas (SNG) and liquid synfuels produced from coal (Concept 15-4B). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Moderate cost
High environmental impact
Large government subsidies
High water use
Lower air pollution than coal when burned
Higher CO2 emissions than coal
Fig , p. 386

70. 15-5 What Are the Advantages and Disadvantages of Nuclear Energy?
Concept Nuclear power has a low environmental impact and a very low accident risk, but high costs, a low net energy yield, long-lived radioactive wastes, vulnerability to sabotage, and the potential for spreading nuclear weapons technology have limited its use.

71. How Does a Nuclear Fission Reactor Work? (1)
Controlled nuclear fission reaction in a reactor
Light-water reactors
Fueled by uranium ore and packed as pellets in fuel rods and fuel assemblies
Control rods absorb neutrons

72. How Does a Nuclear Fission Reactor Work? (2)
Water is the usual coolant
Containment shell around the core for protection
Water-filled pools or dry casks for storage of radioactive spent fuel rod assemblies 72

73. Light-Water-Moderated and -Cooled Nuclear Power Plant with Water Reactor

74. Small amounts of radioactive gases Control rods Containment shell
Heat exchanger
Waste heat
Turbine
Generator
Steam
Uranium
fuel input
(reactor core)
Hot coolant
Useful electrical energy
25%–30%
Hot water output
Pump
Pump
Figure 15.17
Science: light-water–moderated and –cooled nuclear power plant with a pressurized water reactor. Some nuclear plants withdraw water for cooling from a nearby source of water and return the heated water to such a source, as shown here. Other nuclear plants that do not have access to a source of cooling water transfer the waste heat to the atmosphere by using one or more gigantic cooling towers, as shown in the insert photo of the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania (USA). Question: How does this plant differ from the coal-burning plant in Figure 15-12?
Shielding
Coolant
Pump
Pump
Waste heat
Cool water input
Pressure vessel
Moderator
Coolant passage
Water
Condenser
Water source (river, lake, ocean)
Periodic removal and storage of radioactive wastes and spent fuel assemblies
Periodic removal and storage of radioactive liquid wastes
Fig , p. 387

75. After 3 or 4 Years in a Reactor, Spent Fuel Rods Are Removed and Stored in Water

76. What Is the Nuclear Fuel Cycle?
Mine the uranium
Process the uranium to make the fuel
Use it in the reactor
Safely store the radioactive waste
Decommission the reactor

77. Science: The Nuclear Fuel Cycle

78. Uranium-235 as UF6 Plutonium-239 as PuO2
Decommissioning of reactor
Fuel assemblies
Enrichment of UF6
Reactor
Fuel fabrication
(conversion of enriched UF6 to UO to UO2 and fabrication of fuel assemblies)
Temporary storage of spent fuel assemblies underwater or in dry casks
Conversion of U3O8
to UF6
Uranium-235 as UF6 Plutonium-239 as PuO2
Spent fuel reprocessing
Low-level radiation with long half-life
Figure 15.19
Science: the nuclear fuel cycle (Concept 15-5). As long as a plant is operating safely, this fuel cycle has a fairly low environmental impact and a very low risk of an accident. But costs are high, radioactive wastes must be stored safely for thousands of years, and facilities are vulnerable to terrorist attack. Also, the technology can be used to produce material for use in nuclear weapons, and an amount equal to about 92% of the energy content of the nuclear fuel is wasted in producing nuclear power. Questions: Do you think the market price of nuclear-generated electricity should include all the costs of the fuel cycle? Explain. If so, how would this affect the use of nuclear power to produce electricity?
Geologic disposal of moderate- and high-level radioactive wastes
Open fuel cycle today
Recycling of nuclear fuel
Fig , p. 389

79. What Happened to Nuclear Power?
Slowest-growing energy source and expected to decline more
Why?
Economics
Poor management
Low net yield of energy of the nuclear fuel cycle
Safety concerns
Need for greater government subsidies
Concerns of transporting uranium

80. Case Study: Worst Commercial Nuclear Power Plant Accident in the U.S.
Three Mile Island
March 29, 1979
Near Harrisburg, PA, U.S.
Nuclear reactor lost its coolant
Led to a partial uncovering and melting of the radioactive core
Unknown amounts of radioactivity escaped
People fled the area
Increased public concerns for safety
Led to improved safety regulations in the U.S.

81. Case Study: Worst Nuclear Power Plant Accident in the World
Chernobyl
April 26, 1986
In Chernobyl, Ukraine
Series of explosions caused the roof of a reactor building to blow off
Partial meltdown and fire for 10 days
Huge radioactive cloud spread over many countries and eventually the world
350,000 people left their homes
Effects on human health, water supply, and agriculture

82. Remains of a Nuclear Reactor at the Chernobyl Nuclear Power Plant

83. Nuclear Power Has Advantages and Disadvantages

84. Trade-Offs: Conventional Nuclear Fuel Cycle, Advantages and Disadvantages

85. TRADE-OFFS Conventional Nuclear Fuel Cycle Advantages Disadvantages
Large fuel supply
Cannot compete economically without huge government subsidies
Low environmental impact (without accidents)
Low net energy yield
High environmental impact (with major accidents)
Emits 1/6 as much CO2 as coal
Moderate land disruption and water pollution (without accidents)
Environmental costs not included in market price
Risk of catastrophic accidents
Figure 15.21
Advantages and disadvantages of using the nuclear power fuel cycle (Figure 15-19) to produce electricity (Concept 15-5). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Moderate land use
No widely acceptable solution for long-term storage of radioactive wastes
Low risk of accidents because of multiple safety systems (except for Chernobyl-type reactors)
Subject to terrorist attacks
Spreads knowledge and technology for building nuclear weapons
Fig , p. 391

86. Trade-Offs: Coal versus Nuclear to Produce Electricity

87. TRADE-OFFS Coal vs. Nuclear Coal Nuclear Ample supply
Ample supply of uranium
High net energy yield
Low net energy yield
Very high air pollution
Low air pollution
High CO2 emissions
Low CO2 emissions
Much lower land disruption from surface mining
Figure 15.22
Comparison of the risks of using the nuclear power fuel cycle and coal-burning plants to produce electricity. A 1,000-megawatt nuclear plant is refueled once a year, whereas a coal plant of the same size requires 80 rail cars of coal a day. Question: If you had to choose, would you rather live next door to a coal-fired power plant or a nuclear power plant? Explain.
High land disruption from surface mining
Moderate land use
High land use
Low cost (with huge subsidies)
High cost (even with huge subsidies)
Fig , p. 392

88. Nuclear Power Plants Are Vulnerable to Terrorists Acts
Explosions or meltdowns possible at the power plants
Storage pools and casks are more vulnerable to attack
60 countries have or have the ability to build nuclear weapons

89. Dealing with Radioactive Wastes Produced by Nuclear Power Is a Difficult Problem
High-level radioactive wastes
Must be stored safely for 10,000–240,000 years
Where to store it
Deep burial: safest and cheapest option
Would any method of burial last long enough?
There is still no facility
Can the harmful isotopes be changed into harmless isotopes?

90. Case Study: Experts Disagree about What to Do with Radioactive Wastes in the U.S.
1985: plans in the U.S. to build a repository for high-level radioactive wastes in the Yucca Mountain desert region (Nevada)
Problems
Cost: $58–100 billion
Large number of shipments to the site: protection from attack?
Rock fractures
Earthquake zone
Decrease national security

91. What Do We Do with Worn-Out Nuclear Power Plants?
Decommission or retire the power plant
Some options
Dismantle the plant and safely store the radioactive materials
Enclose the plant behind a physical barrier with full-time security until a storage facility has been built
Enclose the plant in a tomb
Monitor this for thousands of years

92. Can Nuclear Power Lessen Dependence on Imported Oil, Reduce Global Warming?
Nuclear power plants: no CO2 emission
Nuclear fuel cycle: emits CO2
Opposing views on nuclear power and global warming
Nuclear power advocates
2003 study by MIT researchers
2007: Oxford Research Group

93. Will Nuclear Fusion Save Us?
“Nuclear fusion is the power of the future and always will be”
Still in the laboratory phase after 50 years of research and $34 billion dollars
2006: U.S., China, Russia, Japan, South Korea, and European Union
Will build a large-scale experimental nuclear fusion reactor by 2040

94. Experts Disagree about the Future of Nuclear Power
Proponents of nuclear power
Fund more research and development
Pilot-plant testing of potentially cheaper and safer reactors
Test breeder fission and nuclear fusion
Opponents of nuclear power
Fund rapid development of energy efficient and renewable energy resources

95. Science Focus: Are New and Safer Nuclear Reactors the Answer? (1)
Advanced light-water reactors (ALWR)
Built-in passive safety features
High-temperature-gas-cooled reactors (HTGC)
Pebble bed modular reactor (PBMR)
Pros: no need to shut down for refueling
Cons
Breeder nuclear fission reactors

96. Science Focus: Are New and Safer Nuclear Reactors the Answer? (2)
New Generation nuclear reactors must satisfy these five criteria
Safe-runaway chain reaction is impossible
Fuel can not be used for nuclear weapons
Easily disposed of fuel
Nuclear fuel cycle must generate a higher net energy yield than other alternative fuels, without huge government subsidies
Emit fewer greenhouse gases than other fuels

97. Animation: Chernobyl fallout

98. Video: Nuclear energy