复旦大学：《能源与环境 Energy and the Environment》教学课件_7_Energy and the environment VII

Energy and the Environment CHEN HONG E-mail:chong@fudan.edu.cn Phone:021-65642526 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Energy and the Environment CHEN HONG E-mail: chong@fudan.edu.cn Phone: 021-65642526

Nuclear Energy Science. engineering economics health satety, psychology, politics Nuclear energy Nuclear weapons Nuclear accident Nuclear energy, radioactivity, radiation, criticality, meltdown 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy Science, engineering, economics, health, safety, psychology, politics Nuclear energy Nuclear weapons Nuclear accident Nuclear energy, radioactivity, radiation, criticality, meltdown

Nuclear Energy Positive features Reactors are not affected by the looming shortage of fossil fuels, and they emit no cO sO. co, or particulates into atm Uranium reactor fuel is now reasonably abundant and inexpensIve, and a breeder(增殖堆) reactor technology could extend the resource to many thousands of years US, 104 power reactors 20%o electricity, T capacity 97,000 MWe france. 78% of the electricity comes from nuclear reactors 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy Positive features: Reactors are not affected by the looming shortage of fossil fuels, and they emit no CO2, SO2, CO, or particulates into atm. Uranium reactor fuel is now reasonably abundant and inexpensive, and a breeder(增殖堆) reactor technology could extend the resource to many thousands of years. US, 104 power reactors 20% electricity , T capacity 97,000 MWe France, 78% of the electricity comes from nuclear reactors

Nuclear Energy US1978 No new orders have been placed for reactors by the public utilities in the United States since 1978. and there have been many cancellations of orders placed before that time Negative side Economics, stringent regulatory procedures, radioactive waste storage, and siting problems France. for example are moving ahead with nuclear electric power programs 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy US 1978 No new orders have been placed for reactors by the public utilities in the United States since 1978, and there have been many cancellations of orders placed before that time. France, for example, are moving ahead with nuclear electric power programs. Negative side: Economics, stringent regulatory procedures, radioactive waste storage, and siting problems

Nuclear Energy The reactor safety record is as good or better than that of any other electricity-producing technology More reliable, less expensive, and safer reactors 25-year period of development from 1953-1978 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy The reactor safety record is as good or better than that of any other electricity-producing technology. More reliable, less expensive, and safer reactors. 25-year period of development from 1953-1978

Nuclear Energy Short history 1930, atom made up of neutrons and protons 1.67X10-27kg 1840 times heavier than electron A Z N Mass Atomic(proton) Number of number number neutrons ME=Am.c2 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy Short History 1930, atom made up of neutrons and protons. 1.67×10-27 kg 1840 times heavier than electron A = Z + N Mass number Atomic (proton) number Number of neutrons ∆E=∆m·c2

Nuclear Energy Chemical reactions: a few eV Nuclear fission reactions: hundreds of mev per atom Pushed apart by Coulomb repulsion, the positively charged energetic fission fragments move away form the site of the fission reaction and come to stop in the surrounding material. In this way their kinetic energy very quickly becomes heat energy in the material 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy Chemical reactions: a few eV Nuclear fission reactions: hundreds of MeV per atom Pushed apart by Coulomb repulsion, the positively charged energetic fission fragments move away form the site of the fission reaction and come to stop in the surrounding material. In this way their kinetic energy very quickly becomes heat energy in the material

Nuclear Energy Neutron Barium Gamma Figure 6. 1 Three steps in the neutron-induced fission of 235U. The combination of a neutron and 235U forms 236U in a highly excited state, that promptly fissions into two lighter nuclei, emitting neutrons and gamma rays in the process The two fragments are called fission products and they carry off about 160 Mev of kinetic energy from the fission reaction 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy The two fragments are called fission products, and they carry off about 160 MeV of kinetic energy from the fission reaction

Nuclear Energy Growing rate, release a large amount of energy in a short time f(=a If the rate of the chain reaction could be controlled by some means so that it was steady, rather than increasing, then one would have a source of heat energy appropriate to drive an electric generator World War Il, Nazi military occupation of much of Europe immediately following the discovery of fission, the initial efforts to exploit this new phenomenon centered on producing a nuclear weapon rather than a nuclear power reactor 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy Growing rate, release a large amount of energy in a short time. If the rate of the chain reaction could be controlled by some means so that it was steady , rather than increasing, then one would have a source of heat energy appropriate to drive an electric generator. World War II, Nazi military occupation of much of Europe immediately following the discovery of fission, the initial efforts to exploit this new phenomenon centered on producing a nuclear weapon rather than a nuclear power reactor. x f (x) = a

Nuclear Energy The first nuclear reactor was assembled at the university of Chicago in 1942 by Enrico Fermi and co-worker. They successfully demonstrated a chain reaction, even though it was at a very low power level about 200 watts Abundance Manhattan Project 235 Los Alamos. New mexico 20143 0.70 Oak ridge, Tennessee, etc 238 920146 99.39 3 Nuclear bomb Critical Mass 15kg 23SU Ist, test in New Mexico, July, 1945 5kg 239Pu Hiroshima nagasaki, august, 1945 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Nuclear Energy The first nuclear reactor was assembled at the University of Chicago in 1942 by Enrico Fermi and co-worker. They successfully demonstrated a chain reaction, even though it was at a very low power level about 200 watts. Manhattan Project Los Alamos, New Mexico; Oak Ridge, Tennessee, etc. Critical Mass 15kg 235U, 5kg 239Pu 235 92U143 238 92U146 0.7% 99.3% 3 Nuclear bomb 1st, test in New Mexico, July, 1945. Hiroshima Nagasaki, August, 1945 Abundance