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Nuclear Energy. Nuclear Energy. most striking development in sources of power in recent years. Release of the atom. How long…. Have we known about atomic power?. Ancient Greeks. included atomic theory as one of their philosophical studies
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Nuclear Energy • most striking development in sources of power in recent years. • Release of the atom
How long….. • Have we known about atomic power?
Ancient Greeks • included atomic theory as one of their philosophical studies • Knowledge about atoms was developed in the 17th century
Early 1900’s • theory became clarified
1940”s • atom was split • resulting power was put to work
Nuclear fission • the nuclei of heavy atoms are split under bombardment by neutrons
Nuclear fission • when a sufficient amount of fissionable material is brought together • chain reaction occurs
Nuclear fission • splitting atoms and releasing a tremendous amount of heat
Nuclear fission • approximately 20,000 times as much heat and energy is released from uranium fuels as from an equivalent amount of coal
Use of fission power • 1945 • first large scale use • atomic bombs were used by the US to knock Japan out of WWII
WWII • since then attention has been given to the peaceful uses of atomic energy
1980 • the amount of electrical power generated by nuclear power plants was about 11% of the total electrical supplies in the US
Energy from fission • atomic energy in the US today is produced by the process known as nuclear fission
Fuel supplies • adequate supplies for nuclear power • major mineral sources for nuclear power • Uranium 238 • Thorium 232
Fuel • from those - U 235 and Plutonium 239 can be produced • in the early stages of development US relied heavily upon imports of uranium
Fuel • from South Africa and Canada
1950’s and 60’s • western US deposits were developed • Bureau of Mines reported that -
. • “Domestic production is adequate to supply present and near-future domestic requirements.”
In 1981 • US was still the world leading miner of uranium
Nuclear Fusion • Fusion is combining together • the atoms are fused together rather than split apart • possibilities for nuclear fusion are much greater than those for nuclear fission
Fusion • problems • process is so difficult to control that it is questionable whether commercial adaptation will ever be economically feasible
Problems • fusion requires extreme pressure and temperatures • as high as 100 million degrees
Problems • such heat was achieved by the Hydrogen bomb • by first setting off a fission explosion
Fuel for fusion • fusion reactors would be fueled by deuterium • an isotope of hydrogen • available in almost unlimited supply in sea water
US Government • demonstration fusion reactor • hopes to have in operation by 2015
LWR • Light Water Reactor • use ordinary water • have been in commercial use since 1957
LWR • free from environmental problems of coal fired electric power plants
LWR disadvantages • potential of a reactor explosion • contamination form atomic wastes • construction costs and technical problems
Safety? • 1974 report stated of Nuclear Power
Safety? • “its use poses serious environmental issues, including reactor safety, radioactive waste management and nuclear theft……..
Safety? • A very hazardous enterprise.”
Three Mile Island • March 28, 1979 • Human and mechanical failure led to the release of a considerable amount of radioactivity
Three Mile Island • evacuation of preschool children and pregnant women within five miles of the plant
Three Mile Island • Nevertheless • 67 nuclear facilities are expected to continued operating • 90 were planned for construction by 1990
Safety Institutions • two • Nuclear Safety Analysis Center • monitors performance of safety
Safety Institutions • Institute of Nuclear Power • inspects existing reactors and evaluates them
Industrial Significance • peaceful use • development of under-seas and space nuclear power • medical use of radioisotopes
Industrial Significance • research in nuclear physics • ensnarled by many problems technological, economic and social
Breeder Reactors • fast breeder reactors • more efficient to operate than LWR’s are undergoing experiment
Breeder Reactors • two types • LMFBR • Liquid Metal Fast Breeder Reactor
Breeder Reactors • GCFBR • Gas cooled fast breeder reactor
Breeder Reactors • they produce more fuel than they consume • more efficient than LWR’s
Breeder Reactors • can use 50-70% of the uranium mined in contrast to only 2% by the LWR
Breeder Reactors • safety problems for the LMFBR may prove to be more sever than those of the LWR
1950’s • Atomic Energy Commission stated: • all new power plants under construction would be atomic powered
1950’s • nuclear energy would account for one half of all the electricity generated
1950’s forecast • does not seem likely to happen • it takes 10-12 years to get a nuclear plant in operation from the first time it is planned
1950’s forecast • no new plant orders were signed in the early 1980’s due to the Three Mile Island accident.
1974 • American Scientists and Engineers completed a study • assessed the possibilities of accident risks in nuclear reactors…...