E N D
1. Environmental Science: Toward a Sustainable Future Richard T. Wright Energy from Nuclear Power PPT by Clark E. Adams
2. Energy from Nuclear Power Nuclear energy in perspective
How nuclear power works
The hazards and costs of nuclear power facilities
More advanced reactors
The future of nuclear power
3. Nuclear Energy in Perspective
4. Nuclear Energy in Perspective
5. Nuclear Energy in Perspective
6. How Nuclear Power Works From mass to energy
Comparing nuclear power to coal power
7. From Mass to Energy
8. Terms and Definitions Fission: a large atom of one element is split to produce two different smaller elements
Fusion: two small atoms combine to form a larger atom of a different element
Isotope: different (mass number) forms of the same element
9. Two Forms of Uranium 238U = 92 protons + 146 neutrons
235U = 92 protons + 143 neutrons
10. Fission, Fusion, or Both? Energy is released
Begins with 235U
Produces radioactive by-products
Produces free neutrons
11. Fission, Fusion, or Both? Splits a larger atom into smaller atoms
Fuses smaller atoms in one larger atom
Begins with 2H and 3H
Produces helium
12. Terms and Definitions Fuel rods: rods full of 235U pellets
Moderator: fluid (water) coolant that slows down neutrons
Control rods: moderate rate of the chain reaction by absorbing neutrons
13. A Nuclear Reactor
14. A Nuclear Reactor Is Designed to Sustain a continuous chain reaction
Prevent amplification into a nuclear explosion
Consist of an array of fuel and control rods
Make some material intensely hot
15. A Nuclear Power Plant
16. A Nuclear Power Plant Designed to Use steam to drive turbogenerators
Convert steam into electricity
Produce superheated water in a reactor vessel
Prevent meltdown
17. Comparing Nuclear Power with Coal Power
18. Comparing Nuclear Power with Coal Power Requires 3.5 million tons of raw fuel
Requires 30 tons of raw material
Emits over 7 million tons of CO2 into the atmosphere
Emits no CO2 into the atmosphere
19. Comparing Nuclear Power with Coal Power Emits over 300 thousand tons of SO2 into the atmosphere
Emits no acid-forming pollutants
Produces about 100 thousand tons of ash
Produces 250 tons of radioactive waste
Possible meltdown
20. Comparing Nuclear Power with Coal Power Produces 250 tons of radioactive waste
Possible meltdown
21. Terms and Definitions Radioisotopes: unstable isotopes of the elements resulting from the fission process
22. Terms and Definitions Radioactive emissions: subatomic particles (neutrons) and high-energy radiation (alpha, beta, and gamma rays)
Radioactive wastes: materials that become radioactive by absorbing neutrons from the fission process
23. The Hazards and Costs of Nuclear Power Facilities Radioactive emissions
Radioactive wastes
Disposal of radioactive wastes
Nuclear power accidents
Safety and nuclear power
Economic problems with nuclear power
24. Radioactive Emissions and Wastes
25. Radioactive Decay
27. Half-life Molybdenum-99 (half-life = 2.8 days)
Xenon-133 (half-life = 5.3 days)
Krypton-85 (half-life = 10.7 years)
Cesium-137 (half-life = 30.0 years)
Plutonium-239 (half-life = 24,000 years)
28. Disposal of Radioactive Wastes (200 Thousand Tons) Finding long-term containment sites
Transport of highly toxic radioactive wastes across the United States
The lack of any resolution to the radioactive waste problem
Environmental racism
Cost ($60 billion to 1.5 trillion)
29. Disposal of Radioactive Wastes To be safe, plutonium-239 would require 240,000 years (10 half-lives) of containment!
Discuss the implications of this in terms of disposal of radioactive wastes.
Yucca Mountain in southwestern Nevada = the nation’s nuclear waste repository
30. Nuclear Power Accidents Three-mile Island
1979
Harrisburg, PA
Loss of coolant in reactor vessel
Damage so bad, reactor shut down permanently
Unknown amount of radioactive waste released into atmosphere
31. How Chernobyl Blew Up Loss of water coolant perhaps triggered the accident. When the water-circulation system failed, the temperature in the reactor core increased to over 5,000 oF, causing the uranium fuel to begin melting and producing steam that reacted with the zirconium alloy cladding of the fuel rods to produce hydrogen gas.
32. How Chernobyl Blew Up A second reaction between steam and graphite produced free hydrogen and carbon oxides. When this gas combined with oxygen, a blast blew off the top of the building, igniting the graphite. The burning graphite threw a dense cloud of radioactive fission products into the air.
33. Consequences of Radiation Exposure Block cell division
Damage biological tissues and DNA
Death
Cancer
Birth defects
34. Safety and Nuclear Power Passive rather than active safety features
New generations of reactors (ALWRs, see Fig. 13-15)
Terrorism and nuclear power: dirty bombs or outright attacks
35. Economic Problems with Nuclear Power Energy demand estimates were unrealistic.
Costs increases (5x) to comply with new safety standards.
Withdrawal of government subsidies to nuclear industry.
Public protests delayed construction.
Any accident financially ruins the utility.
36. More Advanced Reactors Breeder reactors
Fusion reactors
39. Breeder, Fusion, or Both Creates more fuel than it consumes
Raw material is 238U
Splits atoms
40. Breeder, Fusion, or Both Fuses atoms
Releases energy
Raw material is deuterium and tritium
Source of unprecedented thermal pollution
41. The Future of Nuclear Power: Opposition General distrust of technology
Skepticism of management
Doubt overall safety claims about nuclear power plants
Nuclear power plants are prime targets for terrorist attacks
Nuclear waste disposal problems
42. The Future of Nuclear Power: Rebirth? Need to address public concerns listed in the opposition section.
Waste dilemma must be resolved.
Strong political leadership capable of analyzing the full spectrum of problems associated with the future of nuclear power is needed.
43. End of Chapter 13