This chapter discusses non-renewable energy sources such as fossil fuels and nuclear power. It begins by defining renewable and non-renewable energy sources. It then covers the formation of fossil fuels like coal, oil, and natural gas from ancient biological materials. It discusses issues with extracting and using fossil fuels, such as pollution and environmental damage. The chapter also examines nuclear power, how nuclear fission works, and the nuclear fuel cycle from mining to use in power plants. It addresses both benefits and concerns with nuclear energy.

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ENVIRONMENTAL SCIENCE
A Study of Interrelationships, 16th Edition
Chapter 9
Non – Renewable Energy Sources
Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.

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Outline 1
9.1 Major Energy Sources.
9.2 Resources and
Reserves.
9.3 Fossil-Fuel Formation.
9.4 Issues Related to the
Use of Fossil Fuels.
9.5 Nuclear Power.
© Mike Danneman/Getty Images RF

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Outline 2
9.6 The Nature of Nuclear Energy.
9.7 Nuclear Chain Reaction.
9.8 Nuclear Fission Reactors.
9.9 The Nuclear Fuel Cycle.
9.10 Issues Related to the Use of Nuclear Fuels.

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9.1 Major Energy Sources
Nonrenewable energy sources are those whose resources
are being used faster than can be replenished.
• Coal, oil, and natural gas.
Renewable energy sources replenish themselves or are
continuously present as a feature of the environment.
• Solar, geothermal, tidal, etc.
• They currently provide about 12% of the energy used worldwide,
primarily from hydroelectricity and firewood.

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9.2 Resources and Reserves
A resource is a naturally occurring
substance of use to humans that can
potentially be extracted.
A reserve is a known deposit that
can be economically extracted using
current technology, under certain
economic conditions.
Reserves are smaller than resources.
Reserve levels change as technology
advances, new discoveries are made,
and economic conditions vary.
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Source: Adapted from the U.S. Bureau of Mines.

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9.3 Fossil-Fuel Formation
Coal:
• 300 million years ago there were vast expanses of freshwater
swamps.
• When plants died, they accumulated underwater, forming a
spongy mass of organic material.
• Due to geological changes, some of these deposits were
covered by seas, and covered with sediment.
• Pressure from sediment and heat over time transformed the
organic matter into coal.

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Different Kinds of Coal
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World Coal Reserves (2019)
FIGURE 9.4 Recoverable Coal Reserves of the World 2019
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Source: Data from BP Statistical Review of World Energy, 2020.

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Oil and Natural Gas
Oil and natural gas probably originated from microscopic
marine organisms that accumulated on the ocean floor
and were covered by sediments.
The breakdown of organisms released oil droplets into
the sediment.
• Muddy rock gradually formed shale containing dispersed oil.
• Geologic changes caused migration of oil into porous rock.

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Crude Oil and Natural Gas Deposits
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Changes in Oil Reserves
The proved oil reserves increase as new deposits are
discovered and new technologies allow oil to be extracted
that was not possible previously.
FIGURE 9.2 Changes in Proved Oil
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Source: Data from BP Statistical Review of World Energy, 2020. Comstock Images/Alamy

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9.4 Issues Related to the Use of Fossil
Fuels
Fossil fuels supply 80% of the energy consumed worldwide.

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Coal Use 1
Coal is most abundant fossil fuel.
Primarily used for generating electricity.
There are four categories of coal: Lignite, Sub-bituminous,
Bituminous, and Anthracite.
Lignite:
• High moisture, low energy, crumbly, least desirable form.
Sub-bituminous:
• Lower moisture, higher carbon than lignite.
• Used as fuel for power plants.

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Coal Use 2
Bituminous:
• Low moisture, high carbon content.
• Used in power plants and other industry such as steel making.
• Most widely used because it is easiest to mine and the most
abundant.
Anthracite:
• Has the highest carbon content and is relatively rare.
• It is used primarily in heating buildings and for specialty uses.

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Coal Use: Extraction
There are two extraction methods:
Surface mining (strip mining), which is the process of removing
material on top of a vein, is efficient but destructive.
Underground mining minimizes surface disturbance but is costly
and dangerous.
• Many miners suffer from black lung disease, a respiratory condition
that results from the accumulation of fine coal-dust particles in the
miners’ lungs.

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Coal Mining Methods
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Landscape Disturbance

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Surface-Mine Reclamation
Source: H.E. Maide, USGS Photo Library Denver
Colorado
Source: H.E. Maide, USGS Photo Library Denver
Colorado
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Environmental Issues: Subsidence
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Source: C.R. Dunrud, U.S. Geological Survey

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Coal Use: Transportation & Pollution
Coal is bulky and causes some transport problems.
Mining creates dust pollution.
Burning coal releases pollutants (For Example, carbon
dioxide, sulfur dioxide and mercury).
• Millions of tons of material are released into atmosphere
annually.
• Mercury is released into the air when coal is burned.
• Increased amounts of atmospheric carbon dioxide are
implicated in global warming.
• Sulfur dioxide releases cause acid precipitation.

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Environmental Issues: Acid Mine Drainage
Acid mine drainage occurs when the combined action of
oxygen, water, and certain bacteria causes the sulfur in coal
to form sulfuric acid.
FIGURE 9.11 Acid Mine Drainage
U.S. Geological Survey (USGS)

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Oil Use 1
The energy content of oil is more concentrated than coal. It
burns cleaner and is easily transported through pipelines.
• These qualities make it ideal for automobile use.

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Oil Use 2
Locating and extracting oil causes less environmental
damage than coal mining.
Once a source of oil has been located, it must be extracted
and transported to the surface.
Primary Recovery methods:
• If water or gas pressure associated with the oil is great enough,
the oil is forced to the surface when a well is drilled.
• If water and gas pressure is low, the oil is pumped to the
surface.
• 5 to 30% of the oil is extracted depending on viscosity and
geological characteristics.

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Oil Use 3
Secondary Recovery:
• Water or gas is pumped into a well to drive the oil out of the
pores in the rock.
• This technique allows up to 40% of the oil to be extracted.
Tertiary Recovery:
• Steam is pumped into a well to lower the viscosity of the oil.
• Aggressive pumping of gas or chemicals can be pumped into a
well.
• These methods are expensive and only used with high oil
prices.

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Extraction Methods
Offshore Drilling Secondary Recovery
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© Don Farrall/Photodisc/Getty ImagesRF

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Oil Use 4
Processing:
• As it comes from the ground, oil is not in a form suitable for use,
and must be refined.
• Multiple products can be produced from a single barrel of crude
oil.
Oil Spills:
• Accidental spills only account for about 10% of oil pollution
resulting from shipping.
• The effects are still poorly understood.

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Transportation of Oil – Oil Tanker
© Malcolm Fife/Photodisc//Getty Images RF

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Transportation of Oil – Oil Pipeline
(a) Trans-Alaska pipeline
(a): sarkophoto/Getty Images

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Environmental Issues
Oil Spills From Tankers
It is estimated that
worldwide only about
10% of human-caused oil
pollution comes from
tanker accidents.
Sources of Marine Oil
Pollution
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Decline in Spills from Oil Tankers
FIGURE 9.15 Oil Spills From Tankers
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Source: Data From: International Tanker Owners Pollution Federation.

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Natural Gas Use
The drilling operations to obtain natural gas are similar to
those used for oil.
It is hard to transport and in many places is burned off at oil
fields, but new transportation methods are being developed.
• Liquefaction at −126° F (1/600 volume of gas).
• The public is concerned about the safety of LNG loading
facilities, so they are located off-shore.
It is the least environmentally damaging fossil fuel.
• It releases less carbon dioxide than coal or oil.

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9.5 Nuclear Power
Although nuclear power does not come from a fossil fuel, it is
fueled by uranium, which is obtained from mining and is non-
renewable.
As of September 2020, there were 441 nuclear power
reactors in operation and 53 nuclear power plants under
construction in 19 countries.
Of the 106 nuclear power plants currently being planned,
most are in China, India, and Russia.

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Factors that Influence Attitudes toward
Nuclear Power
• Concerns about safety (accidents, decommissioning,
terrorism, etc.).
• Climate change (Nuclear power does not release carbon
dioxide).
• Antinuclear attitudes.
• Economics (cost of building power plants, Price of
competing fuels).

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Nuclear Reactor Statistics
Table 9.2 Nuclear Reactor Statistics September 2020
Region Reactors Operable
Reactors Under
Construction Reactors Planned
World 441 53 106
United States 95 3 3
France 56 1 0
China 48 12 44
Russia 38 4 24
Japan 33 2 1
South Korea 24 4 0
India 22 7 14
Canada 19 0 0
United Kingdom 15 2 2
Ukraine 15 2 0
Sweden 7 0 0
Spain 7 0 0
Belgium 7 0 0
Czech Republic 6 0 1
Germany 6 0 0
Rest of World 43 17 17
Source: Data from World Nuclear Association.

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Distribution of Nuclear Power Plants in
North America
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© Image State/age footstock RF

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9.6 The Nature of Nuclear Energy 1
The nuclei of certain atoms are unstable and spontaneously
decompose. These isotopes are radioactive.
Neutrons, electrons, protons, and other larger particles are
released during nuclear disintegration, along with a great
deal of energy.
Radioactive half-life is the time it takes for half the
radioactive material to spontaneously decompose.

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Half-Lives and Significance of Some
Radioactive Isotopes
Table 9.3 Half-Lives and Significance of Some Radioactive Isotopes
Radioactive Isotope Half-Life Significance
Uranium-235 700 million
years
Fuel in nuclear power plants
Plutonium-239 24,110 years Nuclear weapons
Fuel in some nuclear power plants
Carbon-14 5,730 years Establish age of certain fossils
Americium-241 432.2 years Used in smoke detectors
Cesium-137 30.17 years Treat prostate cancer
Used to measure thickness of objects in industry
Strontium-90 29.1 years Power source in space vehicles
Treat bone tumors
Cobalt-60 5.27 years Sterilize food by irradiation
Cancer therapy
Inspect welding seams
Iridium-192 73.82 days Inspect welding seams
Treat certain cancers
Phosphorus-32 14.3 days Radioactive tracer in biological studies
Iodine-131 8.06 days Diagnose and treat thyroid cancer
Radon-222 3.8 days Naturally occurs in atmosphere of some regions where it causes lung cancers
Radon-220 54.5 seconds Naturally occurs in atmosphere of some regions where it causes lung cancers

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9.6 The Nature of Nuclear Energy 2
Nuclear disintegration releases energy from the nucleus as
radiation, of which there are three major types:
Alpha radiation consists of moving particles composed of two
neutrons and two protons.
• It can be stopped by the outer layer of skin.
Beta radiation consists of electrons from the nucleus.
• It can be stopped by a layer of clothing, glass, or aluminum.
Gamma radiation is a form of electromagnetic radiation.
• It can pass through your body, several centimeters of lead, or a
meter of concrete.

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9.7 Nuclear Chain Reaction 1
Nuclear fission occurs when moving neutrons impact and
split the nuclei of certain other atoms.
In a nuclear chain reaction, splitting nuclei release
neutrons, which themselves strike more nuclei, in turn
releasing even more neutrons.

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9.7 Nuclear Chain Reaction 2
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9.7 Nuclear Chain Reaction 3
Only certain kinds of atoms are suitable for development of a
nuclear chain reaction.
The two most common are uranium-235 and plutonium-239.
There also must be a certain quantity of nuclear fuel (critical
mass) for the chain reaction to occur.

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9.8 Nuclear Fission Reactors 1
A nuclear reactor is a device that permits a sustained,
controlled nuclear fission chain reaction.
The most common nuclear fuel uranium-235 (U-235).
• When the nucleus of a U-235 atom is struck by a slowly moving
neutron from another atom, the nucleus splits into smaller
particles.
• More neutrons are released, which strike more atoms.
• The chain reaction continues to release energy until the fuel is
spent or neutrons are prevented from striking U-235 nuclei.

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9.8 Nuclear Fission Reactors 2
A moderator is a substance that absorbs energy, which
slows neutrons, enabling them to split the nuclei of other
atoms more effectively.
• Water and graphite are the most commonly used.
Control rods made of a non-fissionable material are lowered
into the reactor to absorb neutrons and control the rate of
fission.
• When they are withdrawn, the rate of fission increases.
Coolant, usually water, manages the heat produced by
transferring it away from the reactor.
• Liquid metals and gases are used as coolants in some reactors.

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9.8 Nuclear Fission Reactors 3
In the production of electricity, a nuclear reactor serves the
same function as a fossil-fuel boiler: it produces heat, which
converts water to steam, which turns a turbine, generating
electricity.
The 3 most common types of reactors are:
• Pressurized-Water (68%).
• Boiling-Water (15%).
• Heavy-Water (10%).
Gas-Cooled Reactors are not popular, and no new plants of
this type are being constructed.

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9.8 Nuclear Fission Reactors 4
Breeder reactors produce nuclear fuel as they produce
electricity.
Liquid sodium efficiently moves heat away from the reactor
core.
• They are called Liquid Metal Fast Breeder Reactors.
• A fast-moving neutron is absorbed by Uranium-238 and
produces Plutonium-239.
• P-239 is fissionable fuel.
• Most breeder reactors are considered experimental.
• Because P-239 can be used in nuclear weapons, breeder
reactors are politically sensitive.

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Formation of Plutonium-239 in a Breeder
Reactor
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9.9 The Nuclear Fuel Cycle 1
• The nuclear fuel cycle begins with the mining of low-grade
uranium ore primarily from Australia, Kazakhstan, Canada,
and Namibia produce about 76 percent of uranium.
• During the milling process the ore is crushed and treated
with a solvent to concentrate the uranium.
• Milling produces yellow-cake, a material containing 70-
90% uranium oxide.

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9.9 The Nuclear Fuel Cycle 2
Naturally occurring uranium contains about 99.3% non-
fissionable U238, and 0.7% fissionable U235.
• It must be enriched to 3% U235 to be concentrated enough for
most nuclear reactors.
• Centrifuges separate the isotopes by their slight differences in
mass. U235 weighs slightly less than U238.
• The enriched uranium is converted into a powder and then into
pellets.
• The pellets are sealed into metal rods (fuel rods).

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9.9 The Nuclear Fuel Cycle 3
• Fuel rods are used in a reactor where fission occurs and
the U-235 concentration slowly decreases.
• After about three years of operation, fuel rods don’t have
enough radioactive material remaining to sustain a chain
reaction.
• Spent fuel rods are replaced by new ones.
• Spent rods are still very radioactive, containing about 1%
U-235 and 1% plutonium.

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9.9 The Nuclear Fuel Cycle 4
Spent fuel rods are radioactive and must be managed
carefully to prevent health risks and environmental damage.
Rods can be reprocessed.
• U-235 and plutonium are separated from the spent fuel and
used to manufacture new fuel rods.
• Less than half of the world’s fuel rods are reprocessed.
At present, India, Japan, Russia, France, and the United
Kingdom operate reprocessing plants as an alternative to
storing rods as waste.

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9.9 The Nuclear Fuel Cycle 5
Rods that are not reprocessed are placed in long-term
storage.
Currently stored onsite at the nuclear power plant.
• Initially in pools of water.
• After the radioactivity of the rods declines, they are stored above
ground.
Ultimately, they are to be stored underground.

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Steps in the Nuclear Fuel Cycle
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Source: U.S. Department of Energy.

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9.9 The Nuclear Fuel Cycle
(Transportation)
• All the processes involved in the nuclear fuel cycle have
the potential to generate waste.
• Each step in the nuclear fuel cycle involves the transport of
radioactive materials.
• Each of these links in the fuel cycle presents the possibility
of an accident or mishandling that could release
radioactive material.

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9.10 Issues Related to the Use of Nuclear
Fuels
• Most of the concerns about the use of nuclear fuels relate
to the danger associated with radiation.
• The absorbed dose is the amount of energy absorbed by
matter. It is measured in grays or rads.
• The damage caused by alpha particles is 20 times greater
than that caused by beta particles or gamma rays.
• The dose equivalent is the absorbed dose times a quality
factor.

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The Biological Effects of Ionizing
Radiation 1
When alpha or beta particles or gamma radiation interact
with atoms, ions are formed. Therefore, it is known as
ionizing radiation.
Ionizing radiation alters biological molecules.
Ionizing radiation affects DNA and can cause mutations.
• Mutations that occur in some tissues of the body may manifest
themselves as abnormal tissue growths known as cancers.

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The Biological Effects of Ionizing
Radiation 2
Large doses of radiation are clearly lethal.
Demonstrating known harmful biological effects from smaller
doses is much more difficult.
The more radiation a person receives, the more likely it is
that there will be biological consequences.
Time, distance, and shielding are the basic principles of
radiation protection.
• Water, lead, and concrete are common materials used for
shielding from gamma radiation.

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Protective Equipment
©Getty Images RF

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Radiation Effects
Table 9.4 Radiation Effects
Source or Benchmark Dose Biological Effects
Nuclear bomb blast or accidental exposure in a nuclear facility 100,000 rems/incident Immediate death
Nuclear accident or accidental exposure to X rays 10,000 rems/incident
1,000 rems/incident
800 rems/incident
500 rems/incident
100 rems/incident
50 rems/incident
10 rems/incident
Coma, death in 1–2 days
Death in 2–3 weeks
100% death eventually
50% survival with good
medical care
Increased probability of
leukemia
Changes in numbers of blood
cells observed
Early embryos may show
abnormalities
X ray of intestine
Upper limit for occupationally exposed persons
Upper limit for release from nuclear facilities that are not nuclear
power plants
Natural background radiation
Upper limit for exposure of general public to radiation above
background
Upper limit for release from nuclear power plants
1 rem/procedure
5 rems/year
0.5 rem/year
0.2–0.3 rem/year
0.1 rem/year
0.005 rem/year
Damage or effects difficult to
demonstrate

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Reactor Safety Three Mile Island
The Three Mile Island nuclear plant in Pennsylvania
experienced a partial core meltdown on March 28, 1979.
• It began with pump and valve malfunction, but operator error
compounded the problem.
• The containment structure prevented the release of radioactive
materials from the core, but radioactive steam was vented into
the atmosphere.
• The crippled reactor was defueled in 1990 at a cost of about $1
billion.
• Placed in monitored storage until its companion reactor was
shut down.
• Its companion reactor was shut down in 2019, and both reactors
will be decommissioned.

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Three Mile Island Both reactors are now
shut down
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©Doug Sherman/Geofile RF

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Reactor Safety Chernobyl 1
Chernobyl is a small city in Ukraine, north of Kiev.
It is the site of the world’s largest nuclear accident, which
occurred April 26, 1986.
• Experiments were being conducted on reactor.
• Operators violated six important safety rules.
• They shut off all automatic warning systems, automatic
shutdown systems, and the emergency core cooling system for
the reactor.

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Reactor Safety Chernobyl 2
In 4.5 seconds, the energy level of the reactor increased
2000 times.
The cooling water converted to steam and blew the 1000-
metric ton concrete roof from the reactor.
The reactor core caught fire.
It took 10 days to bring the burning reactor under control.

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Reactor Safety Chernobyl 3
There were 37 deaths; 500 people hospitalized (237 with
acute radiation sickness); 116,000 people evacuated.
• 24,000 evacuees received high doses of radiation.
• Children or fetuses exposed to fallout are showing increased
frequency of thyroid cancer because of exposure to radioactive
iodine 131 released from Chernobyl.
• A permanent containment structure was placed over the
damage reactor in 2016.

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Containment Structure at Chernobyl
FIGURE 9.25 The Accident at Chernobyl
Sodel Vladyslav/Shutterstock

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Reactor Safety Fukushima 1
The Fukushima nuclear power plant was damaged on March
11, 2011 following a magnitude 9 earthquake and tsunami.
• Heat exchangers were damaged, power to the site was cut off,
and the diesel generators designed to provide power in an
emergency were flooded and stopped operating.
• Explosions, fires, and leaks in the cooling system released
radiation into the atmosphere and sea water.

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Reactor Safety Fukushima 2
• About 30 employees and contractors received high levels
of radioactivity.
• An evacuation zone was established around the site.
Some areas are still restricted.
• All 6 reactors at the Fukushima were permanently shut
down.
• The Japanese government shut down all nuclear power
plants in the country for revaluation of their safety. By
2020, 24 nuclear power plants were scheduled for
decommissioning and 16 were granted permission to
restart.

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Terrorism
• After Sept. 11, 2001, fear arose regarding nuclear plants
as potential targets for terrorist attacks.
• Nuclear experts feel aircraft wouldn’t significantly damage
the containment building or reactor, and normal emergency
and containment functions would prevent the release of
radioactive materials.
• Probably the greatest terrorism-related threat is from
radiological dispersal devices (RDDs), or dirty bombs.
They cause panic, not numerous deaths.

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Decommissioning Nuclear Power
Plants 1
The life expectancy of most electrical generating plants
(fossil fuel or nuclear) is 30-40 years.
Unlike other plants, nuclear plants are decommissioned,
not demolished.
Decommissioning is a 2-step process.
• Stage 1 includes removing, properly disposing of or storing fuel
rods and water used in the reactor.
• Stage 2 is the final disposition of the facility.

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Decommissioning Nuclear Power
Plants 2
There are three options to this second stage of the
decommissioning process:
1. Decontaminate and dismantle the plant as soon as it is shut
down.
2. Secure the plant for many years to allow radioactive materials
that have a short half-life to disintegrate and then dismantle the
plant. (However, this process should be completed within 60
years.).
3. Entomb the contaminated portions of the plant by covering the
reactor with reinforced concrete and placing a barrier around
the plant. (Currently this option is only considered suitable for
small research facilities.).

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Decommissioning Nuclear Power
Plants 3
Today, about 170 commercial nuclear power plants,about 48
experimental reactors, and about 500 research reactors in
the world have been shut down and are in various stages of
being decommissioned.
• Recent experience indicates that the cost for decommissioning
a large plant will be between $200 million and $400 million,
about 5 percent of the cost of generating electricity. Although the
mechanisms vary among countries, the money for
decommissioning is generally collected over the useful life of the
plant.

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Summary 1
Resources are naturally occurring substances of use to
humans.
Reserves are known deposits from which materials can be
extracted profitably with existing technology under present
economic conditions.
Coal is the world’s most abundant fossil fuel.
The supply of oil, like all fossil fuels, is limited.
Natural gas is another major source of fossil-fuel energy, but
transport of natural gas to consumers is problematic.

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Summary 2
Nuclear fission is the splitting of the nucleus of an atom.
All reactors contain a core with fuel, a moderator to control
the rate of the reaction, and a cooling mechanism to prevent
the reactor from overheating.
The nuclear fuel cycle involves mining and enriching the
original uranium ore, fabricating it into fuel rods, using the
fuel in reactors, and reprocessing or storing the spent fuel
rods.
Fuel and wastes must also be transported.
Each step in the process presents a danger of exposure.

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Summary 3
Although accidents at Three Mile Island and Chernobyl
raised safety concerns for a time, rising energy prices have
stimulated increased building of nuclear power plants in
many countries.
Disposal of waste is expensive and controversial.
• Long-term storage in geologically stable regions is supported.
• Russia, Japan, and the UK operate nuclear reprocessing
facilities to reduce future long-term storage needs.

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