Phase diagram of water

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Historical Milestones Nuclear Power 1896 Becquerel Fogging of photographic plates near U salts 1905 Einstein Special theory of relativity- E = mc 2 1911 Rutherford Discovery of nucleus - α-particle scattering 1913 Bohr Quantum model of H atom 1932 Chadwick Discovery of neutron 1936 Bohr, Frenkel Liquid drop model of nucleus 1938 Hahn, Strassmann Discovery of fission 1939 Joliot, von Halban Discovery of neutrons produced in fission Kowarski reactions possibility of ‘chain reaction’ 1939 Szilard, Wigner Advised Roosevelt of feasibility of uranium bomb 1939 Booth, Dunning, Start of projects to separate isotopes of Urey 235 U and 238 U 1940 Anderson, Fermi Showed that 12 C would be a good moderator 1940 Joliot, Dautry Transferred D 2 O from Norway to UK 1940 Seaborg Discovered Plutonium 1942 Groves Manhattan Project started 1942 Fermi First nuclear reactor- demonstrated that chain reaction controllable 1943 Bethe, Weisskopf Defined specification of atomic bomb Teller, Feynman (sub-critical sphere surrounded by explosives compression criticality) May 1945 July 1945 Aug 1945 Experimental uranium bomb exploded Experimental plutonium bomb exploded Hiroshima destroyed by U-bomb Nagasaki destroyed by Pu-bomb First self-sustaining chain reaction Fermi December 1942 Chicago University Stadium 1945 UKAEA established in UK, CEA established in France 1954 Fast reactor programme started 1956 First prototype power station (Calder Hall) – gas cooled 1956 Suez crisis oil shortage nuclear power stations first commercial reactors 1962 (Berkeley, Bradwell) 1957 Pressurised Water Reactor (PWR) developed for nuclear submarines by the USA 1957 Windscale fire (Wigner energy underestimated) 1957 Campaign for Nuclear Disarmament (CND) established 1959 Dounreay fast reactor critical 1964 UK decide to build Advanced Gas cooled Reactors (AGR) 1976 First AGRs commissioned (Hinckley B, Hunterston B) 1979 Three Mile Island accident (operator errors) 1986 Chernobyl accident (design faults, operator errors, no regulation 1991/2 Collapse of communism in E.Europe nuclear cooperation (civil and military) 1995 First PWR in UK (Sizewell B)
B/A Fusion Binding Energy of Nuclei Fission Mass Number A MeV Above mass ~20 approximately constant binding energy per nucleon However: more stable nuclei can be formed either by: i) Fusion (combining 2 nuclei with low mass number A) ii) Fission (breakup of large A nucleus into lower A fragments plus release of neutrons) 8 6 4 2 0 In fission A 1 → A 2 + A 3 + neutrons, where A 2 and A 3 are the final stable nuclei, the total energy release E R is approximately E R = A 2 {b(A 2 ) − b(A 1 )} + A 3 {b(A 3 ) − b(A 1 )}. Basic Ideas : Fission Reactors 141 Ba 56 n n 235 236 U U n 92 92 n neutron 92 Kr absorption 36 fission n + 235 U 92 141 Ba 56 + 92 Kr 36 + 3n Change in mass, δm = 3.6 10 −28 kg Energy released, E = (δm)c 2 = (3 10 8 ) 2 3.6 10 −28 = 3.2 10 −11 J ⇒ chain reaction cf chemical combustion C + O 2 CO 2 E = 7 10 −19 J Energy release from 1 uranium nucleus = 5 10 7 carbon atoms 1 tonne of 235 U = 2.7 10 6 tonnes of coal U is 0.7% 235 U so 1 tonne U ≡ 20,000 tonnes of coal Naturally-occurring uranium consists of • fissile isotope 235 U • stable isotope 238 U }ratio = 1/138 ~ 0.7% In a reactor, neutrons are lost by : 1) absorption by 238 U 239 U 239 Pu 2) absorption by 235 U 236 U (18% for thermal n) 3) absorption by moderator 4) absorption by reactor structure 5) escape from reactor core Not enough n to continue chain reaction with H 2 O moderation enrichment necessary to increase ratio 235 U/ 238 U 3% Note: the naturally-occurring ratio was higher in the past % Oklo ‘reactor’ (Gabon) 3 0.7 −2.10 9 −10 9 0 years β nb t 1/2 of 235 U = 7.1 10 8 years cf t 1/2 of 238 U = 3 10 9 years Fuel Enrichment Enrichment is process of increasing proportion of fissionable nuclei in natural uranium (0.7% 235 U) Methods of enrichment 1 Electromagnetic Separation accelerating electrodes B mv 2 /r = qBv r = mv/qB vacuum chamber heavy isotope light isotope Used for Manhattan project (1g/day) and by Iraq before Gulf War
Page 1 and 2: Thermal Power Origins of Steam Powe
Page 3 and 4: Frictional losses across turbine bl
Page 5: Types of Fossil Fuel Power Stations
Page 9 and 10: Macroscopic cross-sections for natu
Page 11 and 12: Safety Features in a PWR • The co
Page 13 and 14: Environmental Impact of Nuclear Pow

Phase diagram of water

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