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5/5/14 - QOTD. Where is Chernobyl located? A. Russia B. Ukraine C. Germany D. United States. CHAPTER 13: E-N-E-R-G-Y. 13-4: What are the advantages and disadvantages of Nuclear Energy?. Conventional Nuclear Power Plants.
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5/5/14 - QOTD • Where is Chernobyl located? • A. Russia • B. Ukraine • C. Germany • D. United States
CHAPTER 13: E-N-E-R-G-Y 13-4: What are the advantages and disadvantages of Nuclear Energy?
Conventional Nuclear Power Plants • Uses heat produced by a controlled nuclear chain reaction to boil water to produce steam that turns a turbine to produce electricity
FISSION REACTION • Light Water Reactors (85% of world’s reactors) • Control rods are moved in and out of the reactor core to absorb neutrons controlling the rate of reaction
2) A water coolant circulates through the reactor’s core to regulate the temperature avoiding a meltdown
3) Containment Vessel is built to surround the reactor core to contain any meltdowns or external catastrophes
4) Storage of used fuel (yearly) is contained in water-filled pools or concrete casks (used fuel rods are dangerously radioactive for up to 240,000 years)
Nuclear Fuel Cycle • Mining Uranium • Processing and Enriching Uranium for fuel • Using the Fuel for 1 year • Safely storing the spent fuel • Retiring the entire nuclear power plant Only 20% surplus of energy
Does Nuclear Power Live up to its Hype? • 1950s experts thought that nuclear power was going to end the need for fossil fuels • By 1973 no new power plants were constructed
What Happened? • Costs too much to build • Costs too much to operate • Poor Management • Malfunctions • Safety Concerns and accidents (3-mile Island and Chernobyl) • Nowadays, concerns over terrorist attacks • Same technology to produce nuclear weapons
Nuclear Power Advantages • Large Fuel Supply • Low Environmental Impact • Emits 1/6 the carbon dioxide as coal • Moderate land disruption and water pollution • Moderate land use • Low risk of accidents because of multiple safety systems Disadvantages • Cannot compete economically without huge government subsidies • Low net energy yield • High environmental impact if accident occurs • Environmental costs not included in market price • Risk of catastrophic accident • No widely acceptable solution for long-term storage of radioactive waste • Subject to terrorist attacks • Spreads knowledge and technology for building nuclear weapons
Storing Radioactive Waste is a BIG Problem • After 10 years a spent fuel rod could kill a person in 3 minutes standing 3 feet away! • 2002 Yucca Mountain, Nevada storage site • $100 billion project not yet off the ground due to legal battles • Scientists do not think it is a good site because of water and seismic activity
Worn Out Nuclear Power Plants • Corrosion and radiation damage to the metal parts of a nuclear power plant allow for about a 60 year lifespan • Potential Options to decommission a plant: • Dismantle the plant piece by piece and store it in a high-level nuclear waste storage facility (none exist at this time) • Build a fence around the plant and guard it for the next 100 years until the radioactive levels have diminished • Enclose the entire plant in a concrete tomb and monitor it for several thousand years
Does Nuclear Power really reduce our dependence on foreign oil and reduce global warming? • NO, only 1% of our electricity comes from oil. • The nuclear fuel cycle still produces carbon dioxide, just not as much
New and Safer Reactors- Nah! • Advanced Light Water Reactors • High-Temperature-Gas Cooled Reactors • Breeder Nuclear Fission Reactors • These reactors may be more efficient and safer to operate but still do not answer the question of what to do with the radioactive waste or decommissioned reactors.
Nuclear Fusion • Fusing one atom of deuterium and tritium to form helium at 100 million degrees and releasing huge amounts of energy. • Scientists still have not figured out a way to get higher outputs of energy than inputs. • Maybe it will be feasible but not for some time yet in the future
Activities • 1) Years of Operation Worksheet • 2) Pollution Pathways due tomorrow