Chapter 12 Nuclear Energy

Introduction to the Nuclear Process Fission – nuclear energy released when atom split Fusion – nuclear energy released when atoms fused

Introduction to the Nuclear Process Atoms and Radioactivity Normally: # protons = # neutrons = # electrons Neutron (0) Atomic mass = # protons + # neutrons Nucleus Electron (-) Proton (+) Atomic number = # protons

Introduction to the Nuclear Process Normally, # proton = # electrons = # neutrons 8 P 8 N Oxygen 6 P 6 N Carbon Differing # proton = different atom

Introduction to the Nuclear Process Carbon If # neutrons > # protons = Isotope Chemical behavior identical to normal atom. Many are radioactive

Introduction to the Nuclear Process Common Radioactive Isotopes

Nuclear Fission Nuclear Fuel Cycle Uranium tailings Uranium mines and mills Depleted uranium tails U-235 enrichment Factory wastes Fabrication of fuel assemblies Low-level wastes Nuclear power plant Spent fuel stored on-site Spent fuel reprocessing Deep geological disposal

Nuclear Fission

Nuclear Fission How Electricity is Produced from Conventional Nuclear Fission

Nuclear Fission Breeder Nuclear Fission

Pros and Cons of Nuclear Energy Impact Coal Nuclear Land use 17,000 ac 1,900 ac Daily fuel requirement 9,000 tons/day 3 kg/day Air pollution Moderate to severe Low Radioactive emissions 1 curie 28,000 curies Risk from catastrophic accidents Short-term local risk Long-term risk over large area

Pros and Cons of Nuclear Energy Is Electricity Produced by Nuclear Energy Cheap? Role of government subsidies The cost of building a nuclear power plant Fixing technical and safety problems in existing plants

Pros and Cons of Nuclear Energy Can Nuclear Energy Decrease Our Reliance on Foreign Oil? Only 3% of electricity in US generated by oil Oil primarily used for: heating buildings vehicles

Safety Issues in Nuclear Power Plants Probability of major accident low, but if it occurs, consequences are wide-spread and long-lasting Major accidents have included: Three Mile Island Chornobyl

Safety Issues in Nuclear Power Plants Radioactive fallout from Chornobyl:

Safety Issues in Nuclear Power Plants The Link Between Nuclear Energy and Nuclear Weapons Can be reprocessed for . . . Spent fuel from conventional nuclear plant Fuel for breeder reactor OR Nuclear weapons

Radioactive Wastes Two general types: Low-level radioactive wastes High-level radioactive wastes

Radioactive Wastes Temporary storage includes above-ground storage casks Insert Fig 12.10 a, b

Radioactive Wastes Case-in-Point: Yucca Mountain

Radioactive Wastes Other considerations: High-Level Radioactive Liquid Waste Radioactive Wastes with Relatively Short Half-Lives Decommissioning Nuclear Power Plants

Fusion: Nuclear Energy for the Future?

The Future of Nuclear Power Issues: Making nuclear power safer Standardizing power plant designs