Mrs. Sealy

1
Ch. 14 Notes Energy

• Mrs. Sealy
• APES

2
I. Mining Law of 1872 encouraged mineral
exploration and mining.

• 1. First declare your belief that minerals on the
  land. Then spend 500 in improvements, pay 100
  per year and the land is yours
• 2. Domestic and foreign companies take out 2-3
  billion/ year
• 3. Allows corporations and individuals to claim
  ownership of U.S. public lands.
• 4. Leads to exploitation of land and mineral
  resources.
•  

http//seattlepi.nwsource.com/specials/mining/2687
5_mine11.shtml
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• "This archaic, 132-year-old law permits mining
  companies to gouge billions of dollars worth of
  minerals from public lands, without paying one
  red cent to the real owners, the American
  people.  And, these same companies often leave
  the unsuspecting taxpayers with the bill for the
  billions of dollars required to clean up the
  environmental mess left behind."
• -- Senator Dale Bumpers (D-AR, retired)

4
Nature and Formation of Mineral Resources

• A. Nonrenewable Resources a concentration of
  naturally occurring material in or on the earths
  crust that can be extracted and processed at an
  affordable cost. Non-renewable resources are
  mineral and energy resources such as coal, oil,
  gold, and copper that take a long period of time
  to produce.

5
Nature and Formation of Mineral Resources

• 1. Metallic Mineral Resources iron, copper,
  aluminum
• 2. Nonmetallic Mineral Resources salt, gypsum,
  clay, sand, phosphates, water and soil.
• 3. Energy resource coal, oil, natural gas and
  uranium

6
Nature and Formation of Mineral Resources

• B.  Identified Resources deposits of a
  nonrenewable mineral resource that have a known
  location, quantity and quality based on direct
  geological evidence and measurements
• C.  Undiscovered Resources potential supplies of
  nonrenewable mineral resources that are assumed
  to exist on the basis of geologic knowledge and
  theory (specific locations, quantity and quality
  are not known)
• D.  Reserves identified resources of minerals
  that can be extracted profitably at current
  prices.
• Other Resources resources that are not
  classified as reserves.

7
Ore Formation

• 1. Magma (molten rock) magma cools and
  crystallizes into various layers of mineral
  containing igneous rock.

8
Ore Formation

• Hydrothermal Processes most common way of
  mineral formation
• A. Gaps in sea floor are formed by retreating
  tectonic plates
• B. Water enters gaps and comes in contact with
  magma
• C. Superheated water dissolves minerals from rock
  or magma
• D. Metal bearing solutions cool to form
  hydrothermal ore deposits.
• E. Black Smokers upwelling magma solidifies.
  Miniature volcanoes shoot hot, black, mineral
  rich water through vents of solidified magma on
  the seafloor. Support chemosynthetic organisms.

9
Ore Formation

• Manganese Nodules (pacific ocean) ore nodules
  crystallized from hot solutions arising from
  volcanic activity. Contain manganese, iron
  copper and nickel.

10
Ore Formation

• 3.      Sedimentary Processes sediments settle
  and form ore deposits.
• A. Placer Deposits site of sediment deposition
  near bedrock or course gravel in streams
• B. Precipitation Water evaporates in the desert
  to form evaporite mineral deposits. (salt, borax,
  sodium carbonate)
• C. Weathering water dissolves soluble metal
  ions from soil and rock near earths surface.
  Ions of insoluble compounds are left in the soil
  to form residual deposits of metal ores such as
  iron and aluminum (bauxite ore).

11
Methods For Finding Mineral Deposits

• A. Photos and Satellite Images
• B. Airplanes fly with radiation equipment and
  magnetometers
• C. Gravimeter (density)
• D. Drilling
• E. Electric Resistance Measurement
• F. Seismic Surveys
• G. Chemical analysis of water and plants

12
Mineral Extraction

• Surface Mining overburden (soil and rock on top
  of ore) is removed and becomes spoil. 
• 1. open pit mining digging holes
• 2. Dredging scraping up underwater mineral
  deposits
• 3. Area Strip Mining on a flat area an
  earthmover strips overburden
• 4. Contour Strip Mining scraping ore from hilly
  areas

13
Subsurface Mining 

• 1. dig a deep vertical shaft,  blast underground
  tunnels to get mineral deposit, remove ore or
  coal and transport to surface     
• 2. disturbs less land and produces less waste
• 3. less resource recovered, more dangerous and
  expensive
• 4. Dangers collapse, explosions (natural gas),
  and lung disease

14
Environmental Impacts of Mineral Resources

• A. Scarring and disruption of land,
• B. Collapse or subsidence
• C. Wind and water erosion of toxic laced mine
  waste
• D. Air pollution toxic chemicals
• E. Exposure of animals to toxic waste
• F. Acid mine drainage seeping rainwater carries
  sulfuric acid ( acid comes from bacteria breaking
  down iron sulfides) from the mine to local
  waterway

Google earth
15
Steps
Environmental Effects
Disturbed land mining accidents health hazards
mine waste dumping oil spills and blowouts
noise ugliness heat
Mining
exploration, extraction
Processing
Solid wastes radioactive material air, water,
and soil pollution noise safety and
health hazards ugliness heat
transportation, purification, manufacturing
Noise ugliness thermal water pollution pollution
of air, water, and soil solid and radioactive
wastes safety and health hazards heat
Use
transportation or transmission to individual
user, eventual use, and discarding
Fig. 14.6, p. 326
16
Subsurface Mine Opening
Surface Mine
Runoff of sediment
Acid drainage from reaction of mineral or ore
with water
Spoil banks
Percolation to groundwater
Leaching may carry acids into soil
and ground water supplies
Leaching of toxic metals and other compounds from
mine spoil
Fig. 14.7, p. 326
17
Smelting
Separation of ore from gangue
Melting metal
Conversion to product
Metal ore
Recycling
Discarding of product
Surface mining
Fig. 14.8, p. 327
Scattered in environment
18
A.     Life Cycle of Metal Resources (fig. 14-8)

• Mining Ore
• A. Ore has two components gangue(waste) and
  desired metal
• B. Separation of ore and gangue which leaves
  tailings
• C. Smelting (air and water pollution and
  hazardous waste which
  contaminates the
  soil around the smelter for decades)
• D. Melting Metal
• E. Conversion to product and discarding product

19
Economic Impact on Mineral Supplies

• A. Mineral prices are low because of subsidies
  depletion allowances and deduct cost of finding
  more
• B. Mineral scarcity does not raise the market
  prices
• C. Mining Low Grade Ore Some analysts say all we
  need to do is mine more low grade ores to meet
  our need
• 1. We are able to mine low grade ore due
  to improved technology
• 2. The problem is cost of mining and processing,
  availability of fresh water, environmental
  impact 

20
Mine, use, throw away no new discoveries rising
prices
A
Recycle increase reserves by improved
mining technology, higher prices, and new
discoveries
B
Production
Recycle, reuse, reduce consumption
increase reserves by improved mining
technology, higher prices, and new discoveries
C
Present
Depletion time A
Depletion time B
Depletion time C
Fig. 14.9, p. 329
Time
21
Fig. 14.10, p. 329
22
A.     Mining Oceans

• 1. Minerals are found in seawater, but occur in
  too low of a concentration
• 2. Continental shelf can be mined
• 3. Deep Ocean are extremely expensive to extract
  (not currently viable)

23
A. Substitutes for metals

• 1. Materials Revolution
• 2. Ceramics and Plastics
• 3. Some substitutes are inferior (aluminum for
  copper in wire)
• 4. Will be difficult to find substitutes for
  helium, manganese, phosphorus and copper

24
Evaluating Energy Sources

• What types of energy do we use?
• 1. 99 of our heat energy comes directly from the
  sun (renewable fusion of hydrogen atoms)
• 2. Indirect forms of solar energy (renewable)
• wind
• hydro
• biomass

25
Coal
Oil and Natural Gas
Geothermal Energy
Hot water storage
Contour strip mining
Floating oil drilling platform
Oil storage
Geothermal power plant
Oil drilling platform on legs
Area strip mining
Pipeline
Pipeline
Oil well
Drilling tower
Mined coal
Gas well
Valves
Water penetrates down through the rock
Pump
Underground coal mine
Water is heated and brought up as dry steam
or wet steam
Impervious rock
Natural gas
Oil
Hot rock
Water
Water
Magma
Fig. 14.11, p. 332
26
Society
Kilocalories per Person per Day
Modern industrial (United States)
260,000
Modern industrial (other developed nations)
130,000
Early industrial
60,000
Advanced agricultural
20,000
Early agricultural
12,000
Hunter gatherer
5,000
Primitive
2,000
Fig. 14.12, p. 333
27
Natural Gas 23
Biomass 12
Coal 22
Oil 30
Fig. 14.13a, p. 333
World
28
Natural Gas 22
Coal 22
Oil 40
Fig. 14.13b, p. 333
United States
29
20th Century Trends

• 1. Coal use decreases from 55 to 22
• 2. Oil increased from 2 to 30
• 3. Natural Gas increased from 0 to 25
• 4. Nuclear increased from 0 to 6

30
100
Wood
Coal
80
Natural gas
60
Contribution to total energy consumption (percent)
Oil
40
Hydrogen Solar
20
Nuclear
0
2100
2025
1950
1875
1800
Year
Fig. 14.14, p. 334
31
Evaluating Energy Sources

• Evaluating Energy Resources Take into
  consideration the following
• Availability
• net energy yield
• Cost
• environmental impact

32
Space Heating
Passive solar
5.8
Natural gas
4.9
Oil
4.5
Active solar
1.9
Coal gasification
1.5
Electric resistance heating (coal-fired plant)
0.4
Electric resistance heating (natural-gas-fired
plant)
0.4
Electric resistance heating (nuclear plant)
0.3
Fig. 14.15a, p. 335
33
High-Temperature Industrial Heat
28.2
Surface-mined coal
Underground-mined coal
25.8
Natural gas
4.9
Oil
4.7
Coal gasification
1.5
0.9
Direct solar (highly concentrated by mirrors,
heliostats, or other devices)
Fig. 14.15b, p. 335
34
Transportation
Natural gas
4.9
Gasoline (refined crude oil)
4.1
Biofuel (ethyl alcohol)
1.9
Coal liquefaction
1.4
Oil shale
1.2
Fig. 14.15c, p. 335
35
Net Energy

• Net Energy total amount of energy available
  from a given source minus the amount of energy
  used to get the energy to consumers (locate,
  remove, process and transport)
• G. Net Energy Ratio - ratio of useful energy
  produced to the useful energy used to produce
  it.

36
Oil

• A. Petroleum/Crude Oil thick liquid consisting
  of hundreds of combustible hydrocarbons and
  small concentrations of nitrogen, sulfur, and
  oxygen impurities.
• B. Produced by the decomposition of dead plankton
  that were buried under ancient lakes and oceans.
  It is found dispersed in rocks.

http//www.schoolscience.co.uk/content/4/chemistry
/petroleum/knowl/4/2index.htm?origin.html
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Oil Life Cycle

• 1. Primary Oil Recovery
• a. drill well
• b. pump out light crude oil

• 114

http//science.howstuffworks.com/oil-drilling3.htm
38
Secondary Oil Recovery

• a. pump water under pressure into a well to force
  heavy crude oil toward the well
• b. pump oil and water mixture to the surface
• c. separate oil and water
• d. reuse water to get more oil

39
Tertiary Oil Recovery

• a. inject detergent to dissolve the remaining
  heavy oil
• b. pump mixture to the surface
• c. separate out the oil
• d. reuse detergent

40

• Transport oil to the refinery (pipeline, truck,
  boat)

41
Oil refining

• heating and distilling based on boiling points
  of the various petrochemicals found in the crude
  oil. (fractional distillation in a cracking
  tower) 

42
Gases
Gasoline
Aviation fuel
Heating oil
Diesel oil
Naphtha
Grease and wax
Furnace
Fig. 14.16, p. 337
Asphalt
43
Conversion to product

• a. Industrial organic chemicals
• b. Pesticides
• c. Plastics
• d. Synthetic fibers
• e. Paints
• f. Medicines
• g. Fuel

44
.     Location of World Oil Supplies

• 1. 64 Middle East (67 OPEC 11 countries)
• a. Saudi Arabia (26)
• b. Iraq, Kuwait, Iran, (9-10 each)
• 2. Latin America (14) (Venezuela and Mexico)
• 3. Africa (7)
• 4. Former Soviet Union (6)
• 5. Asia (4) (China 3)
• 6. United States (2.3) we import 52 of the oil
  we use
• 7. Europe (2)

45
Arctic Ocean
Prudhoe Bay
Coal
Beaufort Sea
ALASKA
Gas
Oil
High potential areas
Gulf of Alaska
Valdez
CANADA
Grand Banks
Pacific Ocean
UNITED
STATES
Atlantic Ocean
Fig. 14.17, p. 338
MEXICO
46
70
60
50
40
Oil price per barrel ()
30
20
(1997 dollars)
10
0
1950
1960
1970
1980
1990
2000
2010
Year
Fig. 14.18, p. 339
47
40
2,000 x 109 barrels total
30
Annual production (x 109 barrels per year)
20
10
0
1900
1925
1950
1975
2000
2025
2050
2075
2100
Year
Fig. 14.19a, p. 339
World
48
4
200 x 109 barrels total
1975
3
Undiscovered 32 x 109 barrels
Proven reserves 34 x 109 barrels
Annual production (x 109 barrels per year)
2
1
0
1900
1920
1940
1960
2080
2000
2020
2040
Year
Fig. 14.19b, p. 339
United States
49
286
Coal-fired electricity
Synthetic oil and gas produced from coal
150
100
Coal
86
Oil
58
Natural gas
17
Nuclear power
Fig. 14.20, p. 339
50
Disadvantages
Advantages
Ample supply for 4293 years
Need to find substitute within 50 years
Low cost (with huge subsidies)
Artificially low price encourages waste and
discourages search for alternatives
High net energy yield
Easily transported within and between countries
Air pollution when burned
Low land use
Releases CO2 when burned
Moderate water pollution
Fig. 14.21, p. 340
51
How long will the oil last

• 1. Identified Reserve will last 53 years at
  current usage rates
• 2. Known and projected supplies are likely to be
  80 depleted within 42 to 93 years depending on
  usage rate
• US oil supplies are expected to be depleted
  within 15 to 48 years depending on the annual
  usage rate

52
Heavy Oils

• Oil Shale fine grained sedimentary rock
  containing solid organic combustible material
  called kerogenShale Oil kerogen distilled from
  oil shale.
• a. could meet U.S. crude oil demand for 40 years
  at current usage rates (Colorado, Utah and
  Wyoming public lands)
• Tar Sand mixture of clay sand and water
  containing bitumen (high sulfur heavy oil)

53
Fig. 14.22, p. 340
54
Mined oil shale
Retort
Conveyor
Spent shale
Above Ground
Conveyor
Pipeline
Impurities removed
Shale oil storage
Hydrogen added
Crude oil
Refinery
Air compressors
Sulfur and nitrogen compounds
Air injection
Shale layer
Underground
Fig. 14.23, p. 341
55
Tar sand is mined.
Tar sand is heated until bitumen floats to the
top.
Bitumen vapor Is cooled and condensed.
Pipeline
Hydrogen added
Impurities removed
Synthetic crude oil
Refinery
Fig. 14.24, p. 341
56
(No Transcript)
57
Advantages
Disadvantages
Moderate existing supplies
High costs
Low net energy yield
Large potential supplies
Large amount of water needed to process
Severe land disruption from surface mining
Water pollution from mining residues
Air pollution when burned
CO2 emissions when burned
Fig. 14.25, p. 342
58
XI. Natural Gas

• Natural Gas is a mixture of 50-90 methane (CH4)
  by volume contains smaller amounts of ethane,
  propane, butane and toxic hydrogen sulfide.
• B. Conventional natural gas - lies above most
  reservoirs of crude oil
• C. Unconventional deposits - include coal beds,
  shale rock, deep deposits of tight sands and deep
  zones that contain natural gas dissolved in hot
  hot water

59
Coal
Oil and Natural Gas
Geothermal Energy
Hot water storage
Contour strip mining
Floating oil drilling platform
Oil storage
Geothermal power plant
Oil drilling platform on legs
Area strip mining
Pipeline
Pipeline
Oil well
Drilling tower
Mined coal
Gas well
Valves
Water penetrates down through the rock
Pump
Underground coal mine
Water is heated and brought up as dry steam
or wet steam
Impervious rock
Natural gas
Oil
Hot rock
Water
Water
Magma
Fig. 14.11, p. 332
60
XI. Natural Gas

• Gas Hydrates - an ice-like material that occurs
  in underground deposits (globally)
•  Liquefied Petroleum Gas (LPG) - propane and
  butane are liquefied and removed from natural gas
  fields. Stored in pressurized tanks.
• Liquefied Natural Gas (LNG) - natural gas is
  converted at a very low temperature (-184oC)

61
Where is the worlds natural gas?

• Russia and Kazakhstan - 40Iran - 15Qatar -
  5Saudi Arabia - 4Algeria - 4United States -
  3Nigeria - 3Venezuela - 3

62
Advantages

• 1. Cheaper than Oil
• 2. World reserves - gt125 years
• 3. Easily transported over land (pipeline)
• 4. High net energy yield
• 5. Produces less air pollution than other fossil
  fuels
• 6. Produces less CO2 than coal or oil
• 7. Extracting natural gas damages the environment
  much less that either coal or uranium ore
• 8. Easier to process than oil
• 9. Can be used to transport vehicles
• 10. Can be used in highly efficient fuel cells

63
Advantages
Disadvantages
Ample supplies (125 years)
Releases CO2 when burned
High net energy yield
Methane (a greenhouse gas) can leak from
pipelines
Low cost (with huge subsidies)
Shipped across ocean as highly explosive LNG
Less air pollution than other fossil fuels
Sometimes burned off and wasted at
wells because of low price
Lower CO2 emissions than other fossil fuels
Moderate environ- mental impact
Easily transported by pipeline
Low land use
Good fuel for fuel cells and gas turbines
Fig. 14.26, p. 342
64
Disadvantages

• 1. When processed, H2S and SO2 are released into
  the atmosphere
• 2. Must be converted to LNG before it can be
  shipped (expensive and dangerous)
• 3. Conversion to LNG reduces net energy yield by
  one-fourth
• 4. Can leak into the atmosphere methane is a
  greenhouse gas that is more potent than CO2.

65
XII. Coal

• Coal is a solid, rocklike fossil fuel formed in
  several stages as the buried remains of ancient
  swamp plants that died during the Carboniferous
  period (ended 286 million years ago) subjected
  to intense pressure and heat over millions of
  years.
• Coal is mostly carbon (40-98) small amount of
  water, sulfur and other materials

66
Three types of coal

• lignite (brown coal)
• bituminous coal (soft coal)
• anthracite (hard coal)
• Carbon content increases as coal ages heat
  content increases with carbon content

67
Increasing heat and carbon content
Increasing moisture content
Peat (not a coal)
Lignite (brown coal)
Bituminous Coal (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
Fig. 14.27, p. 344
68
Coal Extraction

• Subsurface Mining - labor intensive worlds
  most dangerous occupation (accidents and black
  lung disease Surface Mining - three types
• 1. Area strip mining2. contour strip mining3.
  open-pit mining
•  

69
Coal
Oil and Natural Gas
Geothermal Energy
Hot water storage
Contour strip mining
Floating oil drilling platform
Oil storage
Geothermal power plant
Oil drilling platform on legs
Area strip mining
Pipeline
Pipeline
Oil well
Drilling tower
Mined coal
Gas well
Valves
Water penetrates down through the rock
Pump
Underground coal mine
Water is heated and brought up as dry steam
or wet steam
Impervious rock
Natural gas
Oil
Hot rock
Water
Water
Magma
Fig. 14.11, p. 332
70
Why we need coal

• Coal provides 25 of worlds commercial energy
  (22 in US).
• Used to make 75 of worlds steel
• Generates 64 of worlds electricity

71
Coal-Fired Electric Power Plant

• Coal is pulverized to a fine dust and burned at a
  high temperature in a huge boiler. Purified water
  in the heat exchanger is converted to
  high-pressure steam that spins the shaft of the
  turbine. The shaft turns the rotor of the
  generator (a large electromagnet) to produce
  electricity.

http//www.eas.asu.edu/holbert/eee463/coal.html
72
. Coal-Fired Electric Power Plant

• Air pollutants are removed using electrostatic
  precipitators (particulate matter) and scrubbers
  (gases). Ash is disposed of in landfills. Sulfur
  dioxide emissions can be reduced by using
  low-sulfur coal.

73
I. Worlds Coal Supplies

• US - 66 of worlds proven reservesIdentified
  reserves should last 220 years at current usage
  rates. Unidentified reserves could last about 900
  years
•  

74
. Pros and Cons of Solid Coal

• Advantages
• Worlds most abundant and dirtiest fossil fuel,
  High net energy yield

75
Advantages
Disadvantages
Ample supplies (225900 years)
Very high environmental impact
Severe land disturbance, air pollution,
and water pollution
High net energy yield
Low cost (with huge subsidies)
High land use (including mining)
Severe threat to human health
High CO2 emissions when burned
Releases radioactive particles and mercury
into air
Fig. 14.28, p. 344
76
Disadvantages

• harmful environmental effects-mining is
  dangerous (accidents and -black lung
  disease)-harms the land and causes water
  pollution-Causes land subsidence-Surface mining
  causes severe land disturbance and soil
  erosion-Surface mined land can be restored -
  involves burying toxic materials, returning land
  to its original contour, and planting vegetation
  (Expensive and not often done)-Acids and toxic
  metals drain from piles of water materials-Coal
  is expensive to transport-Cannot be used in sold
  form in cars (must be converted to liquid or
  gaseous form)-Dirtiest fossil fuel to burn
  releases CO, CO2, SO2, NO, NO2, particulate
  matter (flyash), toxic metals and some
  radioactive elements.-Burning Coal releases
  thousands of times more radioactive particles
  into the atmosphere per unit of energy than does
  a nuclear power plant-Produces more CO2 per unit
  of energy than other fossil fuels and accelerates
  global warming.-A severe threat to human health
  (respiratory disease)

77
Clean Coal Technology

• . Fluidized-bed combustion - developed to burn
  coal more cleanly and efficiently.
• Use of low sulfur coal - reduces SO2 emission
• Coal gasification uses coal to produce
  synthetic natural gas (SNG)
• . Coal liquefaction - produce a liquid fuel -
  methanol or synthetic gasoline

78
Flue gases
Coal
Limestone
Steam
Fluidized bed
Water
Air nozzles
Air
Calcium sulfate and ash
Fig. 14.29, p. 345
79
Raw coal
Recover sulfur
Air or oxygen
Raw gases
Clean Methane gas
Steam
2C Coal

O2
2CO
Pulverizer
Recycle unreacted carbon (char)
CO

3H2
CH4

H2O
Methane (natural gas)
Slag removal
Pulverized coal
Fig. 14.30, p. 345
80
Advantages
Disadvantages
Large potential supply
Low to moderate net energy yield
Higher cost than coal
Vehicle fuel
High environmental impact
Increased surface mining of coal
High water use
Higher CO2 emissions than coal
Fig. 14.31, p. 346
81
Clean Coal Technology

• Synfuels - can be transported by pipeline
  inexpensively burned to produce electricity
  burned to heat houses and water used to propel
  vehicles.

82
XIII. Nuclear Energy

• A. Three reasons why nuclear power plants were
  developed in the late 1950s
• 1. Atomic Energy Commission promised electricity
  at a much lower cost than coal
• 2. US Govt paid 1/4 the cost of building the
  first reactors
• 3. Price Anderson Act protected nuclear industry
  from liability in case of accidents

83
375
300
225
Gigawatts of electricity
150
75
0
1960
1970
1980
1990
2000
2010
2020
Year
Fig. 14.34a, p. 348
84
35
30
25
20
Gigawatts of electricity
15
10
5
0
1960
1970
1980
1990
2000
2010
Year
Fig. 14.34b, p. 348
85
Why is nuclear power on the decline?

• B. Globally, nuclear energy produces only 17 of
  worlds electricity (6 of commercial energy)
• -huge construction overruns-high operating
  costs-frequent malfunctions-false
  assurances-cover-ups by government and
  industry-inflated estimates of electricity
  use-poor management-Chernobyl-Three Mile
  Island-public concerns about safety, cost and
  disposal of radioactive wastes

86
C. How a Nuclear Reactor Works

• Nuclear fission of Uranium-235 and Plutonium-239
  releases energy that is converted into
  high-temperature heat. This rate of conversion is
  controlled. The heat generated can produce
  high-pressure steam that spins turbines that
  generate electricity.

87
Small amounts of Radioactive gases
Waste heat
Electrical power
Steam
Useful energy 25 to 30
Generator
Turbine
Hot water output
Condenser
Pump
Pump
Cool water input
Black
Pump
Waste heat
Water
Waste heat
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. 14.32, p. 346
88
Spent fuel assemblies
Fuel assemblies
Reactor
(conversion of enriched UF6 to UO2 and
fabrication of fuel assemblies)
Open fuel cycle today
Prospective closed end fuel cycle
Fuel fabrication
Interim storage Under water
Enriched UF6
Plutonium-239 as PuO2
Enrichment UF6
Spent fuel reprocessing
Uranium-235 as UF6
High-level radioactive waste or spent
fuel assemblies
Uranium tailings (low level but long half-life)
Conversion of U3O8 to UF6
Processed uranium ore
Geologic disposal of moderate- and
high-level radioactive wastes
Uranium mines and mills Ore and ore concentrate
(U3O8)
Fig. 14.33, p. 347
Front end
Back end
89
D. Light-water reactors (LWR)

• 1. Core containing 35,000-40,000 fuel rods
  containing pellets of uranium oxide fuel. Pellet
  is 97 uranium-238 (nonfissionable isotope) and
  3 uranium-235 (fissionable).
• 2. Control rods - move in and out of the reactor
  to regulate the rate of fission
• 3. Moderator - slows down the neutrons so the
  chain reaction can be kept going liquid water
  in pressurized water reactors solid graphite or
  heavy water (D2O) .
• 4. Coolant - water to remove heat from the
  reactor core and produce steam

90
Decommissioning Power Plants

• 1/3 of fuel rod assemblies must be replaced every
  3-4 years. They are placed in concrete lined
  pools of water (radiation shield and coolant).
• A. Nuclear wastes must be stored for 10,000 years
• B. After 15-40 years of operation, the plant must
  be decommissioned by
• 1. dismantling it
• 2. putting up a physical barrier, or
• 3. enclosing the entire plant in a tomb (to last
  several thousand years)

91
Advantages
Disadvantages
Large fuel supply
High cost (even with large 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)
Catastrophic accidents can happen (Chernobyl)
No acceptable solution for long-term storage
of radioactive wastes and decommissioning
worn-out plants
Moderate land use
Low risk of accidents because of
multiple safety systems (except in 35 poorly
designed and run reactors in former
Soviet Union and Eastern Europe)
Spreads knowledge and technology for building
nuclear weapons
Fig. 14.35, p. 349
92
Coal
Nuclear
Ample supply
Ample supply of uranium
High net energy yield
Low net energy yield
Low air pollution (mostly from fuel reprocessing)
Very high air pollution
High CO2 emissions
Low CO2 emissions (mostly from fuel reprocessing)
65,000 to 200,000 deaths per year in U.S.
About 6,000 deaths per year in U.S.
High land disruption from surface mining
Much lower land disruption from surface mining
High land use
Moderate land use
Low cost (with huge subsidies)
High cost (with huge subsidies)
Fig. 14.36, p. 349
93
F. Advantages of Nuclear Power

• 1. Dont emit air pollutants
• 2. Water pollution and land disruption are low

94
G. Nuclear Power Plant Safety

• 1. Very low risk of exposure to radioactivity
• 2. Three Mile Island - March 29, 1979 No. 2
  reactor lost coolant water due to a series of
  mechanical failures and human error. Core was
  partially uncovered
• 3. Nuclear Regulatory Commission estimates there
  is a 15-45 chance of a complete core meltdown at
  a US reactor during the next 20 years.
• 4. US National Academy of Sciences estimates that
  US nuclear power plants cause 6000 premature
  deaths and 3700 serious genetic defects each year.

http//www.angelfire.com/extreme4/kiddofspeed/chap
ter1.html
95
Crane for moving fuel rods
Steam generator
Water pumps
Chernobyl
Fig. 14.37, p. 350
96
H. Low-Level Radioactive Waste

• 1. Low-level waste gives off small amounts of
  ionizing radiation must be stored for 100-500
  years before decaying to levels that dont pose
  an unacceptable risk to public health and safety
• 2. 1940-1970 low-level waste was put into drums
  and dumped into the oceans. This is still done by
  UK and Pakistan
• 3. Since 1970, waste is buried in commercial,
  government-run landfills.
• 4. Above-ground storage is proposed by a number
  of environmentalists.
• 5. 1990 the NRC proposed redefining low-level
  radioactive waste as essentially nonradioactive.
  That policy was never implemented (as of early
  1999).

97
I. High-Level Radioactive Waste

• 1. Emit large amounts of ionizing radiation for a
  short time and small amounts for a long time.
  Must be stored for about 240,000
• 2. Spent fuel rods wastes from plants that
  produce plutonium and tritium for nuclear weapons.

98
J. Possible Methods of Disposal and their
Drawbacks 

• 1. Bury it deep in the ground
• 2. Shoot it into space or into the sun
• 3. Bury it under the Antarctic ice sheet or the
  Greenland ice cap
• 4. Dump it into descending subduction zones in
  the deep ocean
• 5. Bury it in thick deposits of muck on the deep
  ocean floor
• 6. Change it into harmless (or less harmful)
  isotopes
• 7. Currently high-level waste is stored in the
  DOE 2 billion Waste Isolation Pilot Plant (WIPP)
  near Carlsbad, NM. (supposed to be put into
  operation in 1999)

99
Up to 60 deep trenches dug into clay.
As many as 20 flatbed trucks deliver
waste containers daily.
Barrels are stacked and surrounded with sand.
Covering is mounded to aid rain runoff.
Clay bottom
Fig. 14.38b, p. 351
100
What covers waste
Fig. 14.38c, p. 351
101
Waste container
Fig. 14.38a, p. 351
102
Storage Containers
Fuel rod
Primary canister
Overpack container sealed
Fig. 14.39c, p. 352
103
Underground
Buried and capped
Fig. 14.39d, p. 352
104
Ground Level
Unloaded from train
Lowered down shaft
Fig. 14.39a, p. 352
105
Fig. 14.39b, p. 352
106
K. Worn-Out Nuclear Plants

• 1. Walls of the reactors pressure vessel become
  brittle and thus are more likely to crack.
• 2. Corrosion of pipes and valves

107
3. Decommissioning a power plant (3 methods have
been proposed)

• A. immediate dismantling
• B. mothballing for 30-100 years
• C. entombment (several thousand years)
• 4. Each method involves shutting down the plant,
  removing the spent fuel, draining all liquids,
  flushing all pipes, sending all radioactive
  materials to an approved waste storage site yet
  to be built.

108
Connection between Nuclear Reactors and the
Spread of Nuclear Weapons

• 1. Components, materials and information to build
  and operate reactors can be used to produce
  fissionable isotopes for use in nuclear weapons.

Los Alamos Muon Detector Could Thwart Nuclear
Smugglers
109
M. Can We Afford Nuclear Power?

• 1. Main reason utilities, the government and
  investors are shying away from nuclear power is
  the extremely high cost of making it a safe
  technology.
• 2. All methods of producing electricity have
  average costs well below the costs of nuclear
  power plants.

110
N. Breeder Reactors

• 1. Convert nonfissionable uranium-238 into
  fissionable plutonium-239
• 2. Safety liquid sodium coolant could cause a
  runaway fission chain reaction and a nuclear
  explosion powerful enough to blast open the
  containment building.
• 3. Breeders produce plutonium fuel too slowly it
  would take 1-200 years to produce enough
  plutonium to fuel a significant number of other
  breeder reactors.

111
O. Nuclear Fusion

• 1. D-T nuclear fusion reaction Deuterium and
  Tritium fuse at about 100 million degrees
• 2. Uses more energy than it produces