Energy.ppt

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Chapter Overview Questions

 What are the advantages and disadvantages _{What are the advantages and disadvantages} of conventional oil and nonconventional

of conventional oil and nonconventional

heavy oils?

 What are the advantages and disadvantages _{What are the advantages and disadvantages} of natural gas?

of natural gas?

 What are the advantages and disadvantages _{What are the advantages and disadvantages} of coal and the conversion of coal to gaseous

of coal and the conversion of coal to gaseous

and liquid fuels?

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Chapter Overview Questions (cont’d)

 What are the advantages and disadvantages _{What are the advantages and disadvantages} of conventional nuclear fission, breeder

of conventional nuclear fission, breeder

nuclear fission, and nuclear fusion?

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Core Case Study:

How Long Will the Oil Party Last?

 Saudi Arabia could supply the world with oil _{Saudi Arabia could supply the world with oil} for about 10 years.

for about 10 years.

 The Alaska’s North Slope could meet the _{The Alaska’s North Slope could meet the} world oil demand for 6 months (U.S.: 3

world oil demand for 6 months (U.S.: 3

years).

 Alaska’s Arctic National Wildlife Refuge _{Alaska’s Arctic National Wildlife Refuge} would meet the world demand for 1-5

would meet the world demand for 1-5

months (U.S.: 7-25 months).

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Core Case Study:

How Long Will the Oil Party Last?

 We have three _{We have three} options:

options:

 Look for more oil.Look for more oil.

 Use or waste less oil.Use or waste less oil.  Use something else.Use something else.

Figure 16-1

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TYPES OF ENERGY RESOURCES

 About 99% of the energy we use for heat _{About 99% of the energy we use for heat}

comes from the sun and the other 1% comes

mostly from burning fossil fuels.

 Solar energy indirectly supports wind power, Solar energy indirectly supports wind power, hydropower, and biomass.

hydropower, and biomass.

 About 76% of the commercial energy we use _{About 76% of the commercial energy we use} comes from nonrenewable fossil fuels (oil,

comes from nonrenewable fossil fuels (oil,

natural gas, and coal) with the remainder

coming from renewable sources.

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TYPES OF ENERGY RESOURCES

 Nonrenewable energy resources and _{Nonrenewable energy resources and} geothermal energy in the earth’s crust.

geothermal energy in the earth’s crust.

Figure 16-2

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Fig. 16-2, p. 357 Oil and natural gas

Oil and natural gas Floating oil drilling

platform _{Oil storage} CoalCoal

Contour strip mining Oil drilling platform on legs Geothermal Geothermal energy energy

Hot water storage Oil well

Pipeline Geothermal

power plant Gas

well _Valves _{Mined coal}

Pump Area strip

mining _Drilling

tower

Pipeline

Impervious_rock Undergroun_d coal mine

Natural ga_s

WaterOil _{Water is h}

eated and brought up_{as dry} steam or w_{et steam} Water

Coal seam Hot rock

Water penetrates down through the rock

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TYPES OF ENERGY RESOURCES

 Commercial energy use by source for the _{Commercial energy use by source for the} world (left) and the U.S. (right).

world (left) and the U.S. (right).

Figure 16-3

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Fig. 16-3a, p. 357 Nuclear power 6%

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Fig. 16-3b, p. 357 Hydropower geothermal, solar, wind 3% Nucle

ar po

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TYPES OF ENERGY RESOURCES

 Net energy is the amount of high-quality _{Net energy is the amount of high-quality}

usable energy available from a resource after

subtracting the energy needed to make it

available.

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Net Energy Ratios

 The higher the net energy ratio, the greater _{The higher the net energy ratio, the greater} the net energy available. Ratios < 1 indicate

the net energy available. Ratios < 1 indicate

a net energy loss.

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Fig. 16-4, p. 358 Space Heating

Space Heating

Passive solar _5.8 Natural gas

Oil _4.5

Active solar _1.9 Coal gasification _1.5 Electric resistance heating (coal-fired plant) _0.4

0.4

Electric resistance heating (nuclear plant) _0.3

High-Temperature Industrial Heat 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 Direct solar (highly concentrated by mirrors,

heliostats, or other devices) 0.9

Transportation Transportation

Natural gas _4.9 Gasoline (refined crude oil) _4.1

Biofuel (ethyl alcohol) _1.9 Coal liquefaction 1.4

Oil shale 1.2 Electric resistance heating (natural-gas-fired plant)

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OIL

 Crude oil (petroleum) is a thick liquid _{Crude oil (petroleum) is a thick liquid}

containing hydrocarbons that we extract from

underground deposits and separate into

products such as gasoline, heating oil and

asphalt.

 Only 35-50% can be economically recovered Only 35-50% can be economically recovered from a deposit.

from a deposit.

 As prices rise, about 10-25% more can be As prices rise, about 10-25% more can be

recovered from expensive secondary extraction

techniques.

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OIL

 Refining crude oil:_{Refining crude oil:}

 Based on boiling Based on boiling

points, components

are removed at

various layers in a

giant distillation

column.

 The most volatile The most volatile components with

components with

the lowest boiling

points are removed

at the top.

Figure 16-5

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Fig. 16-5, p. 359

Gases

Gasoline

Aviation fuel

Heating oil

Diesel oil

Naptha

Grease and wax

Asphalt Heated

crude oil

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OIL

 Eleven OPEC (Organization of Petroleum _{Eleven OPEC (Organization of Petroleum}

Exporting Countries) have 78% of the world’s

proven oil reserves and most of the world’s

unproven reserves.

 After global production peaks and begins a _{After global production peaks and begins a} slow decline, oil prices will rise and could

slow decline, oil prices will rise and could

threaten the economies of countries that

have not shifted to new energy alternatives.

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OIL

 Inflation-adjusted price of oil, 1950-2006._{Inflation-adjusted price of oil, 1950-2006.}

Figure 16-6

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Fig. 16-6, p. 361

O

il

p

ri

ce

p

e

r

b

a

rr

e

l (

$

)

(2006 dollars)

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Case Study: U.S. Oil Supplies

 The U.S. – the world’s largest oil user – has _{The U.S. – the world’s largest oil user – has} only 2.9% of the world’s proven oil reserves.

only 2.9% of the world’s proven oil reserves.

 U.S oil production peaked in 1974 (halfway _{U.S oil production peaked in 1974 (halfway} production point).

production point).

 _{About 60% of U.S oil imports goes through}_{About 60% of U.S oil imports goes through} refineries in hurricane-prone regions of the

refineries in hurricane-prone regions of the

Gulf Coast.

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OIL

 Burning oil for _{Burning oil for} transportation

transportation

accounts for 43%

of global CO

of global CO₂₂

emissions.

Figure 16-7

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Fig. 16-7, p. 363

Trade-Offs

Conventional Oil

Advantages Disadvantages

Ample supply for

42–93 years Need to find

substitutes 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

Technology is well developed

Efficient distribution

system Moderate water

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CO

₂₂

Emissions

_Emissions

 COCO₂₂ emissions per unit of energy produced emissions per unit of energy produced for various energy resources.

for various energy resources.

Figure 16-8

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Fig. 16-8, p. 363 Coal-fired

electricity 286%

Synthetic oil and gas

produced from coal 150%

Coal 100%

Oil sand 92%

Natural gas 58%

Oil 86%

Nuclear power fuel cycle

17%

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How Would You Vote?

 Do the advantages of relying on conventional _{Do the advantages of relying on conventional} oil as the world’s major energy resource

oil as the world’s major energy resource

outweigh its disadvantages?

 a. No. The environmental, political, and economic a. No. The environmental, political, and economic costs of petroleum are too high.

costs of petroleum are too high.

 b. Yes. Petroleum is needed until suitable b. Yes. Petroleum is needed until suitable alternatives can be developed and

alternatives can be developed and

commercialized.

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Heavy Oils from Oil Sand and Oil

Shale: Will Sticky Black Gold Save Us?

 Heavy and tarlike oils from oil sand and oil _{Heavy and tarlike oils from oil sand and oil} shale could supplement conventional oil, but

shale could supplement conventional oil, but

there are environmental problems.

there are environmental problems.  High sulfur content.High sulfur content.

 Extracting and processing produces:Extracting and processing produces: • Toxic sludge_{Toxic sludge}

• Uses and contaminates larges volumes of water_{Uses and contaminates larges volumes of water}

• Requires large inputs of natural gas which reduces net _{Requires large inputs of natural gas which reduces net}

energy yield.

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Oil Shales

 Oil shales contain _{Oil shales contain} a solid

a solid

combustible

mixture of

hydrocarbons

called

called kerogenkerogen..

Figure 16-9

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Heavy Oils

 It takes about 1.8 _{It takes about 1.8} metric tons of oil

metric tons of oil

sand to produce

one barrel of oil.

Figure 16-10

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Fig. 16-10, p. 365

Trade-Offs

Heavy Oils from Oil Shale and Oil Sand

Moderate cost (oil sand)

High cost (oil shale)

Low net energy yield

Large potential supplies,

especially oil sands in

Canada Large amount _{of water needed} for processing Easily transported within and between countries Severe land disruption Severe water pollution Efficient distribution system in place Air pollution when burned

CO₂ emissions when burned Technology is

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NATURAL GAS

 Natural gas, consisting mostly of methane, is _{Natural gas, consisting mostly of methane, is} often found above reservoirs of crude oil.

often found above reservoirs of crude oil.

 When a natural gas-field is tapped, gasses are When a natural gas-field is tapped, gasses are liquefied and removed as liquefied petroleum gas

liquefied and removed as liquefied petroleum gas

(LPG).

 Coal beds and bubbles of methane trapped _{Coal beds and bubbles of methane trapped} in ice crystals deep under the arctic

in ice crystals deep under the arctic

permafrost and beneath deep-ocean

sediments are unconventional sources of

natural gas.

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NATURAL GAS

 Russia and Iran have almost half of the _{Russia and Iran have almost half of the} world’s reserves of conventional gas, and

world’s reserves of conventional gas, and

global reserves should last 62-125 years.

 Natural gas is versatile and clean-burning _{Natural gas is versatile and clean-burning} fuel, but it releases the greenhouse gases

fuel, but it releases the greenhouse gases

carbon dioxide (when burned) and methane

(from leaks) into the troposphere.

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NATURAL GAS

 Some analysts see _{Some analysts see} natural gas as the

natural gas as the

best fuel to help us

make the transition to

improved energy

efficiency and greater

use of renewable

energy.

Figure 16-11

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Fig. 16-11, p. 368

Trade-Offs

Conventional Natural Gas

Ample supplies (125 years) Nonrenewable resource

High net energy yield

Releases CO₂ when

burned Low cost (with huge

subsidies)

Methane (a greenhouse gas) can leak from pipelines

Lower CO₂ emissions than

other fossil fuels

Difficult to transfer from one country to another

Moderate environmental

impact Shipped across ocean as

highly explosive LNG Easily transported by pipeline

Sometimes burned off and wasted at wells because of low price

Low land use

Good fuel for fuel cells and gas turbines

Requires pipelines Less air pollution than other

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COAL

 Coal is a solid fossil fuel that is formed in _{Coal is a solid fossil fuel that is formed in}

several stages as the buried remains of land

plants that lived 300-400 million years ago.

Figure 16-12

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Fig. 16-12, p. 368

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

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Fig. 16-12, p. 368 Highly desirable fuel because of its high heat content and low sulfur content;

supplies are limited in most areas

Extensively used as a fuel because of its high heat content and large supplies; normally has a

high sulfur content Low heat content;

low sulfur

content; limited supplies in most areas

Partially

decayed plant matter in

swamps and bogs; low heat content

Increasing heat and carbon content

Increasing moisture content

Peat (not a coal)

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Fig. 16-13, p. 369

Waste heat

Coal bunker Turbine _{transfers waste}Cooling tower heat to atmosphere Generator

Cooling loop

Stack Pulverizing

mill

Condenser _Filter

Boiler

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COAL

 Coal reserves in the United States, Russia, _{Coal reserves in the United States, Russia,} and China could last hundreds to over a

and China could last hundreds to over a

thousand years.

 The U.S. has 27% of the world’s proven coal The U.S. has 27% of the world’s proven coal reserves, followed by Russia (17%), and China

reserves, followed by Russia (17%), and China

(13%).

 In 2005, China and the U.S. accounted for 53% In 2005, China and the U.S. accounted for 53% of the global coal consumption.

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COAL

 Coal is the most _{Coal is the most}

abundant fossil fuel,

but compared to oil

and natural gas it is

not as versatile, has

a high environmental

impact, and releases

much more CO

much more CO₂₂ into into the troposphere.

the troposphere.

Figure 16-14

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Fig. 16-14, p. 370

Trade-Offs Coal

Ample supplies (225–900 years) Severe land disturbance, air pollution, and water pollution High net energy yield

High land use (including mining) Low cost

(with huge subsidies)

Severe threat to human health Well-developed

mining and combustion

technology High CO2

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How Would You Vote?

 Should coal use be phased out over the next _{Should coal use be phased out over the next} 20 years?

20 years?

 a. No. Coal is an abundant energy source and a. No. Coal is an abundant energy source and

we should continue to develop clean ways to use

it.

 b. Yes. Mining and combusting coal create b. Yes. Mining and combusting coal create serious environmental impacts.

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COAL

 Coal can be converted into synthetic natural _{Coal can be converted into synthetic natural} gas (SNG or syngas) and liquid fuels (such

gas (SNG or syngas) and liquid fuels (such

as methanol or synthetic gasoline) that burn

cleaner than coal.

cleaner than coal.  Costs are high.Costs are high.

 Burning them adds more COBurning them adds more CO

2

2 to the troposphere to the troposphere

than burning coal.

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COAL

 Since Since COCO₂₂ is not is not regulated as an air

regulated as an air

pollutant

pollutant and costs are and costs are high, U.S.

high, U.S.

coal-burning plants are

burning plants are

unlikely to invest in

coal gasification.

Figure 16-15

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Fig. 16-15, p. 371

Trade-Offs Synthetic Fuels

Large potential supply Low to moderate net energy yield Higher cost than coal Vehicle fuel Requires mining 50% more coal High environmental impact Moderate cost (with large government subsidies) Increased surface

mining of coal

High water use Lower air

pollution when

burned than coal

Higher CO₂

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NUCLEAR ENERGY

 When isotopes of uranium and plutonium _{When isotopes of uranium and plutonium} undergo controlled nuclear fission, the

undergo controlled nuclear fission, the

resulting heat produces steam that spins

turbines to generate electricity.

 The uranium oxide consists of about 97% The uranium oxide consists of about 97%

nonfissionable uranium-238 and 3% fissionable

uranium-235.

 The concentration of uranium-235 is increased The concentration of uranium-235 is increased through an enrichment process.

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Fig. 16-16, p. 372

Small amounts of radioactive gases Uranium fuel input (reactor core) Control rods Containment shell Heat exchanger

Steam Turbine _Generator

Waste heat Electric power Hot coolant Useful energy 25%–30% Hot water output Pump Pump

Coolant _Pump _Pump

Moderator Cool water input Waste heat Shielding Pressure vessel Coolant passage Water _Condenser

Periodic removal and storage of radioactive wastes and spent fuel assemblies

Periodic removal and storage of radioactive liquid wastes

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NUCLEAR ENERGY

 After three or four _{After three or four} years in a reactor,

years in a reactor,

spent fuel rods are

removed and stored

in a deep pool of

water contained in a

steel-lined concrete

container.

Figure 16-17

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NUCLEAR ENERGY

 After spent fuel rods are cooled considerably, _{After spent fuel rods are cooled considerably,} they are sometimes moved to dry-storage

they are sometimes moved to dry-storage

containers made of steel or concrete.

Figure 16-17

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Fig. 16-18, p. 373 Decommissioning of reactor Fuel assemblies Reactor Enrichment

of UF₆ Fuel fabricationFuel fabrication

(conversion of enriched UF

(conversion of enriched UF₆₆

to UO

to UO₂₂ and fabrication of and fabrication of fuel assemblies)

fuel assemblies) Temporary storage of _{Temporary storage of}

spent fuel assemblies

underwater or in dry

casks

casks Conversion of

U₃O₈ to UF₆

Uranium-235 as UF

Uranium-235 as UF₆₆

Plutonium-239 as PuO

Plutonium-239 as PuO₂₂

Spent fuel Spent fuel reprocessing reprocessing Low-level radiation Low-level radiation

with long half-life

Geologic disposal of moderate & high-level radioactive wastes

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What Happened to Nuclear Power?

 After more than 50 years of development and _{After more than 50 years of development and} enormous government subsidies, nuclear

enormous government subsidies, nuclear

power has not lived up to its promise

because:

 Multi billion-dollar construction costs.Multi billion-dollar construction costs.

 Higher operation costs and more malfunctions Higher operation costs and more malfunctions than expected.

than expected.

 Poor management.Poor management.

 Public concerns about safety and stricter Public concerns about safety and stricter government safety regulations.

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Case Study: The Chernobyl Nuclear

Power Plant Accident

 The world’s worst nuclear power plant _{The world’s worst nuclear power plant} accident occurred in 1986 in Ukraine.

accident occurred in 1986 in Ukraine.

 The disaster was caused by poor reactor _{The disaster was caused by poor reactor} design and human error.

design and human error.

 _{By 2005, 56 people had died from radiation}_{By 2005, 56 people had died from radiation} released.

released.

 4,000 more are expected from thyroid cancer and 4,000 more are expected from thyroid cancer and leukemia.

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NUCLEAR

ENERGY

 In 1995, the World _{In 1995, the World} Bank said nuclear

Bank said nuclear

power is too costly

and risky.

 _{In 2006, it was found}_{In 2006, it was found} that several U.S.

that several U.S.

reactors were leaking

radioactive tritium into

groundwater.

Figure 16-19

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Fig. 16-19, p. 376

Trade-Offs

Conventional Nuclear Fuel Cycle

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

Catastrophic accidents can happen (Chernobyl)

Moderate land disruption and water pollution

(without accidents)

No widely 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 for 15 Chernobyl-type reactors)

Subject to terrorist attacks

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NUCLEAR

ENERGY

 A 1,000 _{A 1,000}

megawatt nuclear

plant is refueled

once a year,

whereas a coal

plant requires 80

rail cars a day.

Figure 16-20

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Fig. 16-20, p. 376

Coal vs. Nuclear Trade-Offs

Coal Nuclear

Ample supply Ample supply of uranium

High net energy yield Low net energy yield

Very high air pollution Low air pollution (mostly _{from fuel reprocessing)}

High CO₂ emissions Low CO₂ emissions (mostly

from fuel reprocessing)

High land disruption from

surface mining Much lower land disruption

from surface mining

Low cost (with huge subsidies) High cost (even with huge subsidies)

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NUCLEAR ENERGY

 Terrorists could attack nuclear power plants, _{Terrorists could attack nuclear power plants,} especially poorly protected pools and casks

especially poorly protected pools and casks

that store spent nuclear fuel rods.

 Terrorists could wrap explosives around _{Terrorists could wrap explosives around}

small amounts of radioactive materials that

are fairly easy to get, detonate such bombs,

and contaminate large areas for decades.

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NUCLEAR ENERGY

 When a nuclear reactor reaches the end of _{When a nuclear reactor reaches the end of} its useful life, its highly radioactive materials

its useful life, its highly radioactive materials

must be kept from reaching the environment

for thousands of years.

 At least 228 large commercial reactors _{At least 228 large commercial reactors}

worldwide (20 in the U.S.) are scheduled for

retirement by 2012.

 Many reactors are applying to extent their 40-Many reactors are applying to extent their 40-year license to 60 40-years.

year license to 60 years.

 Aging reactors are subject to embrittlement and Aging reactors are subject to embrittlement and corrosion.

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NUCLEAR ENERGY

 Building more nuclear power plants will not _{Building more nuclear power plants will not} lessen dependence on imported oil and will

lessen dependence on imported oil and will

not reduce CO

not reduce CO₂₂ emissions as much as other emissions as much as other alternatives.

alternatives.

 The nuclear fuel cycle contributes to COThe nuclear fuel cycle contributes to CO

2

emissions.

 Wind turbines, solar cells, geothermal energy, Wind turbines, solar cells, geothermal energy, and hydrogen contributes much less to CO

and hydrogen contributes much less to CO₂₂

emissions.

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NUCLEAR ENERGY

 Scientists disagree about the best methods _{Scientists disagree about the best methods} for long-term storage of high-level radioactive

for long-term storage of high-level radioactive

waste:

 Bury it deep underground.Bury it deep underground.  Shoot it into space.Shoot it into space.

 Bury it in the Antarctic ice sheet.Bury it in the Antarctic ice sheet.

 Bury it in the deep-ocean floor that is geologically Bury it in the deep-ocean floor that is geologically stable.

stable.

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New and Safer Reactors

 Pebble bed _{Pebble bed}

modular reactor

(PBMR) are

smaller reactors

that minimize the

chances of

runaway chain

reactions.

Figure 16-21

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Fig. 16-21, p. 380

Each pebble contains about 10,000 uranium dioxide

particles the size of a pencil point.

Pebble detail

Silicon carbide

Pyrolytic carbon

Porous buffer

Uranium dioxide

Graphite

shell Helium

Turbine

Generator Pebble

Core Hot

water output

Recuperator Reactor

vessel Water

cooler

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New and Safer Reactors

 Some oppose the pebble reactor due to :_{Some oppose the pebble reactor due to :}

 A crack in the reactor could release radioactivity.A crack in the reactor could release radioactivity.  The design has been rejected by UK and The design has been rejected by UK and

Germany for safety reasons.

 Lack of containment shell would make it easier Lack of containment shell would make it easier for terrorists to blow it up or steal radioactive

for terrorists to blow it up or steal radioactive

material.

 Creates higher amount of nuclear waste and Creates higher amount of nuclear waste and increases waste storage expenses.

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NUCLEAR ENERGY

 Nuclear fusion is a nuclear change in which _{Nuclear fusion is a nuclear change in which} two isotopes are forced together.

two isotopes are forced together.

 No risk of meltdown or radioactive releases.No risk of meltdown or radioactive releases.  May also be used to breakdown toxic material.May also be used to breakdown toxic material.  Still in laboratory stages.Still in laboratory stages.

 _{There is a disagreement over whether to}_{There is a disagreement over whether to}

phase out nuclear power or keep this option

open in case other alternatives do not pan

out.

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