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Nuclear Power Plants : The Past and the Future of Power Nucleus Composed of protons and neutrons 239 Pu 94 or Pu – 239 94 protons 145 neutrons Isotope of Plutonium Radioactivity Some isotopes are unstable Spontaneously Decay Decaying isotopes emit particles Half-life
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Nucleus • Composed of protons and neutrons • 239Pu94 or Pu – 239 • 94 protons • 145 neutrons • Isotope of Plutonium
Radioactivity • Some isotopes are unstable • Spontaneously Decay • Decaying isotopes emit particles
Half-life • Pu-239 decays to U-235 with the emission of an alpha particle: • The time for half of the Pu-239 nuclei to decay is called the half-life. • 24,000 years is half-life for Pu-239 decay
Fission • By bombarding a nucleus with neutrons, a stable isotope can be induced to fission or split. • U-235 is an example of a fissionable material. • The release of neutrons in this reaction means that we can set up a chain reaction
Fission Releases Energy • When the fission is controlled, as in a nuclear reactor, it can be a practical source of power. • When the fission is uncontrolled it can be the basis for weapons of mass destruction.
Fusion • Two light nuclei combine to form a heavier nucleus. • The fusion of deuterium (a hydrogen isotope) with tritium (another hydrogen isotope) to form a helium nucleus can release a great deal of energy.
Fusion Power • Using a fission bomb as a trigger, a hydrogen bomb, or a H-bomb uses fusion to create a WMD. • Solar energy originates as fusion energy in the sun’s interior. • Fusion power is an active area of research.
Nuclear Reactors:Boiling Water Reactor (BWR) • Similar to coal plant: boils water, makes steam, steam drives turbine, turbine turns electrical generator • Fissioning of U-235 is the fuel.
BWR Components • Containment building prevents release of radiation • Water is needed as coolant and to prevent meltdown.
Nuclear Reactor is a Heat Engine • Efficiency is similar to a coal burning plant, about 33% • So, 2/3 of the released energy is waste heat.
Uranium Fuel • Only 0.7% of natural U is U-235. • U-238 is not fissionable. • U must be enriched to 2.8% U-235.
Uranium Fuel Supply • Worldwide U-235 resource does not offer a long-term energy solution. • Breeder reactor consuming U-235 can convert U-238 into Pu-239.
Nuclear Power in the US • 104 nuclear plants • Produce 20% US Electricity • No new plants since 1973 • Why?
Present Uses of Nuclear Power • Plants provide about 17% of the world’s electricity • About 15% of US overall electricity • More than 400 plants around the world, with more than 100 in the US
How many plants, how much energy? • By the end of the 1990’s: • US had in operation 104 power plants • Total output of about 97,000 MWe • Accounting for about 19% of total electricity generated and 5% of our total energy output
WORLDWIDE • the US has more operating reactors than any other country • Some countries supply more than 50% of their electricity from fission • France- 77% • South Korea- 50% with nuclear • Germany- 30% with nuclear • By ’99, there were 425 reactors in operation in the world. • 29 reactors are now under construction
United States • No new reactors have been ordered in the US • Economics have been the chief reason for the decline • The last 20 reactors built in the US cost $3 to $6 billion, or $3,000 to $6,000/KW • A gas fired plant costs almost 10times less
Advantages of Nuclear Power The Ultimate Energy Resource
Uranium is Abundant • Uranium is more abundant than fossil fuels • Uranium 238—130,000 quad • Coal—12,000 quad • Uranium 235—1,800 quad
Nuclear Energy is Cleanand Environmentally Friendly • Nuclear energy emits no harmful gases or toxic metals • It does not alter a region’s ecosystem • Wastes created are far less of a problem than those produced by coal or the silt that builds up behind dams
Big Energy, Small Waste • One lb. of Uranium produces 20,000 times more energy than one pound of coal • Waste is the size of one aspirin tablet per person per year • One plant’s yearly waste would fit comfortably under a dining room table • Coal plants generate 320 lbs. of ash and other poisons per person per year
Is nuclear waste disposal an advantage? • Yes, because it is encapsulated in fireproof, water-proof, and earthquake-proof boron-silicate glass or ceramic • Then it is buried deep in extremely arid ground • The chance that the encapsulated waste will ever harm anyone is virtually zero
Nuclear Energy is Safer for Workers • 100 coal miners are killed each year in the US in accidents and another 100 die transporting it • Per amount of electricity produced, hydropower causes 110 fold, coal 45 fold, and natural gas 10 fold more deaths than nuclear power
NUCLEAR POWER:CONCERNS & PROBLEMS Four Main Areas: Safety Waste Disposal Proliferation Cost Etc.
SafetyBecause of its potential power, nuclear power is frowned upon for its inherent and demonstrated safety risks. • Three Mile Island and Chernobyl • Prime Target for terrorist attacks • No way to completely ensure safety and security in plants
Waste DisposalThere is currently no excellent solution to the problem of waste disposal where nuclear waste is concerned. • Plutonium and uranium can be radioactive for up to 700,000 years • Yucca Mountain not available until 2010, not sufficient if use expanded • Large risks involved for surrounding areas • Problems with long-distance transport, long-term storage
ProliferationMaterials from nuclear power plants could be acquired by groups in search of atomic weapons • Plants hold large amounts of weapons grade uranium and plutonium • Everything available to make nuclear weapons • No way to ensure security against theft and takeovers
CostRight now nuclear energy is not an economically beneficial option for those who would be building/running the plants. • Nuclear plants cost $3-$6 billion to build (10x the cost of a coal plant) • Running cost not as efficient when safety, waste disposal accounted for • Highly trained employees scarce and expensive • Decommissioning a major concern
Is Nuclear Power an Economic Disaster? • Some analysts think so: • As the nuclear industry celebrates a record year for power generation, energy conservation expert Amory Lovins of the Rocky Mountain Institute still considers it an economic disaster. "Nuclear has suffered the greatest collapse of any enterprise in the industrial history of the world." • The industry, he writes, has less than 10 percent of the lowest capacity predicted just 25 years ago by the International Atomic Energy Agency. "No one has made money selling reactors. U.S. investments exceeding a trillion dollars are delivering only about as much energy as bio-fuels" like waste wood and ethanol.
The Future of Nuclear Power:Will Nuclear Make a Comeback? • the current combination of good operating records, a thirst for electricity, and worries about global warming, make nuclear's prospects seem brighter than any time since Three Mile Island melted down • Nuclear engineer Michael Corradini said, “"I'd be willing to bet that in one or two years somebody will order a nuclear power plant. "The utilities are trying to decide which one has the guts enough to do it." • In the last analysis, ordering new reactors will rest more on economics than on public sentiment • There are 433 nuclear reactors in the world, and the public fear did not arise after the last one was built • That fear has been overcome in the past, and if the economics were right, it will be overcome in the future
What does the future hold? “Business as Usual”
What does the future hold? “Business as Usual”
What does the future hold? “Business as Usual”
What does the future hold? “Business as Usual”
Sources • Beckman, Petr. The Health Hazards of Not Going Nuclear. Golem Press: New York, • 1977. • Birol, Fatih. “Nuclear Power in the World Energy Outlook”. 11 April 2004. • <http://www.iisd.ca/2002/wssd/enbots/pdf/enbots1004e.pdf> • Hinrichs, Roger A. and Merlin Kleinbach. Energy Its Use and the Environment. 3rd • Edition, Brooks/Cole, 2002. • Google.com image search http://www.google.com/imghp?hl=en&tab=wi&ie=UTF-8&oe=UTF-8&q= • Miller, Donald. “Advantages of Nuclear Power”. 14 April, 2004. • <www.lewrockwell.com> • Unkown Author. “Nuclear Power”. Nation Master Encyclopedia, 2004. • <www.nationmaster.com/encyclopedia/nuclear-power> • Unknown author. “Nuclear Power: Energy for Today and Tomorrrow”. 30 August, 1999. • http://pw1.netcom.com/~res95/energy/nuclear.html • Webpage of Professor Loxsom, Trinity University Physics <http://www.trinity.edu/floxsom/earthschanging/Energy%20Options/Energy%20Options.htm>