APES Chapter 12
What does "spent" mean in relation to nuclear fuel rods?
"Spent" nuclear fuel rods means that they are no longer sufficiently radioactive to generate electricity efficiently.
Pros of nuclear energy
"clean"energy domestic generates a ton of energy relatively low CO2 emissions
One g of U-235 produces approximately how much more energy than 1 g of coal?
2,000,000 times
For a sample of Ti-44 with a half life of 63 years, how long until 1/16 of the original amount is left?
252 years
Traveling alone in a car uses 3.6 MJ of energy per kilometer. If 4 people go on a trip of 400 miles, what is the MJ used per person?
580 MJ
Describe how a nuclear fission reactor works.
A nuclear fission reactor consists of fuel rods and a steam generator contained in a structure. The fuel rods are filled with uranium pellets which undergo nuclear fission in the core and release heat energy. This heat passeds through a pipe to the steam generator where it heats water into steam. This steam then travels through another pipe to a turbine where it makes it turn, turning the generator to make energy.
Control rods
Absorbs excess neutrons and slows or stops the fission reaction
Which type of coal has the highest energy density
Anthracite
What is anthracite?
Anthracite is 280 to 360 million years old and in a layer 5 m thick. it is made of compressed bituminous.
What happens at the petroleum refinery?
At the refinery, petroleum is heated. Different temperatures produce different products.
What is bituminous?
Bituminous is hundreds of millions of years old and in a layer 5 m thick. It is made of compressed lignite.
Explain why cogeneration is more efficient than thermoelectric power plants which are not cogenerators.
Cogeneration creates heat and electricity at the same time while thermoelectric power plants use steam from water to create electricity. It's the fact that heat is also created in the former which makes it efficient, since then it kills two birds with one stone, so to speak.
Discuss the current options for radioactive waste disposal.
Currently, radioactive waste can be disposed of through storage. It can be stored in nuclear rods in pools of water at the power plants, stored in lead-lined dry containers on land, or kept in a radioactive waste disposal facility. To be truly disposed of, waste would have to be destroyed using chemicals, shot into space, dumped on the ocean floor, or buried in an ocean trench, but all of these methods are dangerous.
Steam line
Directs the steam from the steam generator to the turbine and generator
Core
Encloses a nuclear fission reaction between uranium pellets
Fuel rods
Encloses nuclear fuel within a nuclear reactor
Define energy efficiency. Why do we quantify energy efficiency?
Energy efficiency is the efficiency of the process we use to obtain the fuel and the efficiency of the process that converts it into the work that is needed. We quantify energy efficiency to be able to calculate how much energy is needed for a service and how much unnecessary energy is lost.
What is the difference between energy efficiency and energy quality?
Energy efficiency relates to performing a service without losing unnecessary energy while energy quality compares all of the different types of energy to see which is best.
What is the basic process by which the energy in a fuel is converted into electricity?
Energy in a fuel is burned in a boiler. The energy released is transferred to water to become steam. This steam, which contains kinetic energy, is transferred to a turbine which then rotates. A shaft within the turbine turns a generator which generates electricity.
What is the relationship between energy intensity and energy use per capita?
Energy intensity is energy used per unit of gross domestic product while the latter is energy used per person. The former has been decreasing while the latter has not changed.
Why are fossil fuels and nuclear power both considered nonrenewable energy resources?
Fossil fuels and nuclear power are both nonrenewable because they can't be replenished once they've been used up. Fossil fuels uses ancient material in the earth and nuclear fuel uses radioactive material, both of which do not replenish quickly.
Containment structure
Houses the control rods and steam generator
Describe Hubbert's curve (please use the term "peak oil").
Hubbert's curve shows our use of oil. It considers oil production and time. There are two curves. The higher one shows the upper estimate of reserves while the lower one shows the lower estimate of reserves. The two curves are bell-shaped showing the progress of our use until it reaches "peak oil" then declines until we run out of the supply.
Which makes petroleum convenient to use as a fuel for transportation? I. High energy density II. Clean burning III. Its liquid state
I, II, and III
Where is natural gas found?
It is found above oil in petroleum deposits.
Fukushima
Japan March 11, 2011 A tsunami caused by a 9.0 earthquake flooded the power plant causing fires, explosions, and released radioactive radiation.
Liquefied natural gas (LNG)
LNG is produced from natural gas and methane gas. It is considered eco-friendly or a "green fuel". It is cooled into a liquid and transported in a vessel. It is lighter than air and produces less energy than natural gas.
Liquefied petroleum gas ( LPG)
LPG is mostly propane and butane. It is a clean-burning greenhouse gas. It is compressed into a liquid and transported in a vessel. It is denser than air and produces more energy than petroleum gas.
What is lignite?
Lignite is millions of years old and in a layer 10 m thick. It is made of compressed peat.
What is natural gas?
Natural gas is a gas that is 80 to 95% methane and 5 to 20% ethane, propane, and butane.
Which energy source does not originate from the Sun?
Nuclear
Which nuclear process occurs in stars and which one occurs in nuclear reactors (thermoelectric power plants and submarines).
Nuclear fission occurs in nuclear reactors while nuclear fusion occurs in stars.
describe energy consumption in the US over the past 160 years
Over the past 160 years, energy consumption in the US has increased astronomically, except for wood-derived energy. Oil has risen from 0 to 45, natural gas from 0 to 35, coal from 0 to 15, nuclear from 0 to 10, renewables from 0 to 5, and hydroelectric from 0 to 5; wood has remained at 5.
What is peat?
Peat is the precursor to coal. It is made of partly decomposed organic material. Its layer is only 50 meters thick and it is 0 years old.
Three Mile Island
Pennsylvania March 28, 1979 A cooling water valve was left closed which caused the reactor core to overheat and partially melt down. Radioactive radiation was then released to the outside world.
What products, or petrochemicals, come from the refining process?
Petroleum can be used for gasoline, petrochemicals (plastics), lubricants, pharmaceuticals, and cleaning solvents.
What is petroleum or crude oil?
Petroleum is a fossil fuel that occurs in underground deposits, composed of a liquid mixture of hydrocarbons, water, and sulfur. Crude oil is the liquid form removed from the ground.
What are some major contributors to phantom load in a home and what prevents manufacturers from making electrical items that don't draw phantom load?
Phantom loads are caused by leaving things on or plugged in like battery chargers, instant-on features on TVm computers in sleep mode, and leaving electrical devices on. Manufacturers can turn off devices with buttons, but there is no easy way to completely disconnect a device from the power source.
Why are people concerned about radioactive waste?
Radioactive waste is very toxic/hazardous and difficult to dispose of because it lasts a very long time (meaning that a good location is difficult to find).
What seven countries have the largest petroleum supplies?
Saudi Arabia, Russia, the United States, Iran, China, Canada, and Mexico.
Compare the US's energy consumption to other countries around the world.
The US consumes a level of 100 per year, making it the second highest after China. Per capita, the US consumes at a level of 65, making it the second highest after Canada.
What four countries have the largest coal supplies?
The United States, Russia, China, and India.
How is oil extracted from the earth's crust?
The oil is pumped out of wells drilled into a deposit of the oil (a place where it flows out naturally due to pressure).
If you could carpool with three other people who needed to make the same trip, what would the energy expenditure be for each person? (Show your math and please please please try to complete without a calculator!)
Total expenditure: 1260 MJ → divided by 3 = 420 MJ/person
Chernobyl
Ukraine April 26, 1986 Nuclear reactions continued without control rods or coolant during a test run, causing the plant to overheat. This caused an explosion and fire while releasing radioactive radiation.
Turbine and generator
Where energy is created when the steam makes the turbine and generator rotate
Cooling tower
Where heated water/steam is cooled down using water and rejects the waste heat into the atmosphere
Steam generator
Where the heat energy released from the fission warms the water to create steam
Should we be concerned about the future of fossil fuels?
Yes. Hubbert's conclusion is still seen as possible. That means that we could one day reach our peak then begin to decline our extraction and use. If current trends continue, we may run out of oil in 50 years. However, other supplies will last longer and we may soon completely switch to renewable energy.
Bitumen is
a degraded type of petroleum
What is a fossil fuel?
a fuel derived from biological material that became fossilized millions of years ago
Define radioactive waste.
a nuclear fuel that can no longer produce enough heat to be useful in a power plant but continues to emit radioactivity.
What is coal?
a solid fuel formed primarily from the remains of trees, ferns, and other plant materials preserved 280 million to 360 million years ago.
Control rods slow nuclear reactions by
absorbing excess neutrons
How is coal used?
burned as a fossil fuel, used to generate electricity, and used in industrial processes like making steel.
benefits of using and relying on fossil and nuclear fuels for energy
cheap easily accessible allow us to do a great many things
What are some examples of fossil fuels?
coal oil natural gas
Pros of using petroleum?
convenient to transport and use energy-dense cleaner-burning than coal produces 85% as much CO2 as coal
Pros of drilling oil and natural gas in Alaska's Arctic Wild Refuge ( ANWR)
could yield as much as 95 billion to 1.4 trillion liters
Pros of using coal as an energy resource?
easy to extract through surface mining useful for electricity, energy, and in industrial processes easy to handle needs little refining transported with a train, barge, or truck inexpensive
Which is an example of secondary energy source?
electricity
Liquid Coal
expensive produces a lot of energy tons of greenhouse gas emissions
Cons of nuclear energy
expensive toxic chemicals long half-lives for waste uncertainty of disposal location could make a nuclear weapon possibility of nuclear accidents
Pros of natural gas?
extensive pipeline system cleanest fossil fuel fewer impurities (emits no sulfur dioxide or particulates during combustion) emits only 60% as much CO2 as coal convenient and desirable
Cons of using coal as an energy resource?
harder to find → subsurface mining technological demands increased costs harmful to health contains impurities (pollution) - released through combustion washed with toxic organic compounds chemical spills coal ash air pollution (carbon dioxide, sulfur oxide, mercury)
Cons of drilling oil and natural gas in Alaska's Arctic Wild Refuge ( ANWR)
harm habitat & affect residents
Increased interest in nuclear power due to
low carbon dioxide emissions
Natural gas is primarily
methane
Cons of natural gas?
methane escapes into the atmosphere (super bad for the environment) thumper trucks fracking uses chemicals and water groundwater contamination escaped natural gas
The major source of energy in the US is
oil
The Hubbert Curve predicts that
peak oil will occur once half of the supply is used up
setbacks of using and relying on fossil and nuclear fuels for energy
pollution (oil spills/explosions, mining, emissions) finite resource
The process of fusion
requires extremely high temperatures
Oil Sands
slow-flowing/viscous bitumen mixed with sand, water, and clay extracted by surface mining energy-intensive mining uses a lot of water low efficiency greater CO2 release
Cons of using petroleum?
still releases CO2 releases sulfur and trace metals into the atmosphere with combustion extracted from ground or underneath ocean potential for oil spills expensive
What products come from crude oil?
tar, asphalt, gasoline, diesel, and kerosene
Nuclear fusion is
the combining of two nuclei to create a heavier nucleus.
Nuclear fission is
the splitting of an atom into two nuclei (and with energy release)
Cogeneration is
the use of fuel to generate heat and electricity
How is coal extracted from the earth?
through mining (both surface and subsurface)
How is coal formed?
through the piling up of organic matter and its compression over time.
How is petroleum formed?
when ancient ocean-dwelling phytoplankton die and fill the pore spaces of porous sedimentary rocks then travel upwards where they are blocked in by nonporous one.
