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Learn about nuclear fission, fusion, and the societal debate over nuclear energy. Explore reasons for seeking alternatives to fossil fuels and conventional energy sources. Understand how nuclear energy is harnessed and the challenges it faces. Discover the potential of fusion as a sustainable energy solution.
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AP Environmental Science • Mr. Grant • Lesson 96 Alternatives to Fossil Fuels & Nuclear Power
Objectives: • Define the terms nuclear fission and nuclear fusion. • Discuss the reasons for seeking alternatives to fossil fuels • Summarize the contributions to world energy supplies of conventional alternatives to fossil fuels • Describe nuclear energy and how it is harnessed • Outline the societal debate over nuclear power • TED - Physicist Steven Cowley is certain that nuclear fusion is the only truly sustainable solution to the fuel crisis. He explains why fusion will work -- and details the projects that he and many others have devoted their lives to, working against the clock to create a new source of energy.
Define the terms nuclear fission and nuclear fusion. Nuclear Fission Nuclear Fusion
Discuss the reasons for seeking alternatives to fossil fuels. • Fossil fuels are nonrenewable resources and we are gradually depleting them. • Fossil fuel combustion causes air pollution that results in… • Environmental and health impacts. • Contributes to global climate change.
Summarize the contributions to world energy supplies of conventional alternatives to fossil fuels. • Biomass provides 10% of global primary energy use... • Nuclear power provides 6.3% • Hydropower provides 2.2% • Nuclear power generates 15.2% of the world’s electricity… • Hydropower generates 16.0% • “Conventional energy alternatives” are the alternatives to fossil fuels that are most widely used... • Biomass energy • Nuclear energy • Hydroelectric power • “Conventional energy alternatives” in terms of renewability and environmental impact fall between fossil fuels and less widely used “new renewable” sources.
Describe nuclear energy and how it is harnessed. • Nuclear power comes from converting the energy of subatomic bonds into thermal energy, using uranium isotopes. • Uranium is mined, enriched, processed into pellets and fuel rods, and used in nuclear reactors. • By controlling the reaction rate of nuclear fission, nuclear power plant engineers produce heat that powers electricity generation.
A typical light water reactor: fission in reactors generates electricity
Outline the societal debate over nuclear power. • Advocates of “clean” energy support nuclear power because it lacks the pollutant emissions of fossil fuels. • For many people, the risk of a major nuclear power plant accident (like Chenobyl), outweighs the benefits of clean energy. • The disposal of nuclear waste remains a major dilemma… • Temporary storage and single-repository plans each involve health, security, and environmental risks. • Economic factors and costs overruns have slowed the nuclear industry’s growth.
The Chernobyl accident The destroyed reactor was encased in a massive concrete sarcophagus to contain further leakage
Atmospheric currents carried radioactive fallout from Chernobyl across much of the Northern Hemisphere