330 likes | 452 Views
Fission Energy for War and Peace. Fearing of fission bomb for Hitler first, the U.S. started the Manhattan Project in 1942. Atomic Committee of the Office of Scientific Research and Development (OSRD) was responsible.
E N D
Fission Energy for War and Peace Fearing of fission bomb for Hitler first, the U.S. started the Manhattan Project in 1942. Atomic Committee of the Office of Scientific Research and Development (OSRD) was responsible. OSRD members: E. Lawrence, A.H. Compton, H. Urey (all three were Nobel laureates), L. Briggs, E. Murphree J.B. Conant (director) September 23, 1942, the Uranium Committee met with Secretary of War Henry L. Stimson, Chief of Staff General George C. Marshall and other top military officers including Major General Leslie R. Groves (Executive Officer of Manhattan Project) * * * * Fission Energy for War and Peace
Fission Bomb Project of U.S. and Canada Grove and Chadwick’s talk brought cooperation between Britain and America. Britain and Canada started a large establishment in Montreal under the National Research Council (NRC) of Canada British-Canadian-American joint venture built a heavy-water nuclear reactor in Petawawa, Ontario, to produce both 239Pu and 233U. The first zero-energy experimental pile (ZEEP) started operation on September 7, 1945. * * * * Fission Energy for War and Peace
Producing Bomb Materials Separate 235U (0.7%) from natural uranium: gas diffusion of UF6 centrifuge of UF6 gas thermal diffusion of UF6 gas electromagnetic separation Production of 239Pu by the reaction238U(n, 2b)239Pu Fission Energy for War and Peace
Bomb Material: Separating 235U by gas Diffusion One diffusion unit and the diffusion plant The blue spot is a personhttp://www.npp.hu/uran/3diff-e.htm Fission Energy for War and Peace
Bomb Material: Separating 235U by Electromagnetic method Bomb Material: Separating 235U by Electromagnetic meth The principle of this method is the same as the mass spectrometry for chemical analysis. This is still a very important method for chemical analysis today. Fission Energy for War and Peace
Isotope Separation by Plasma Centrifuge A vacuum arc produces a plasma column which rotates by action of an applied magnetic field. The heavier isotopes concentrate in the outer edge of the plasma column resulting in an enriched mixture that can be selectively extracted Fission Energy for War and Peace
New Methods of Isotope Separation • In the cyclotron resonance method a radiofrequency field selectively energizes one of the ionized isotopes in magnetically confined plasma; isotopes are differentiated and the more energetic atoms are collected. • In the laser induced selective ionization method, the laser is tuned to selectively to ionize U235, but not U238. An electric field extracts the ions from the weakly ionized plasma and guides them up to collecting plates. Fission Energy for War and Peace
Critical Masses for Chain Reactions The minimum quantity for a sustained chain reaction to take place is called the critical mass or critical size, whichdepends on the moderator, chemical and physical states, shape etc. Fission Energy for War and Peace
Reducing Critical Masses by Implosion Fission Energy for War and Peace
Major work sites:Oak Ridge 59,000-acre Hanford Engineer Work 450,000-acreProject Y (Los Alamos Laboratory) Chicago, Berkley, Montreal, New York The First Fission Bomb Explosion July 16, 1945, a plutonium (Fat Man) bomb was tested in Journey of Death. Two hemispheres of 239Pu were forced together to reach criticality. The bomb was attached to a 30-meter steel tower, which disappeared after the explosion. Fission Energy for War and Peace
Fission Energy For War At 8:15 am August 6, 1945, Little Boy (235U) was dropped on Hiroshima by a modified B-29 bomber. On the 9th, a 239Pu-fuelled bomb exploded over Nagasaki Destruction by atomic bomb Light and energy (heat) Shock wave Secondary fire Radioactive fission products in the fallout Fission Energy for War and Peace
The Nuclear Arms Race During 1945-1991 Stalin competed with the U.S. and Britain for military superiority during WWII Science is for everyone to discover, but research is costly, and atomic secret invite spy activities. Development of hydrogen bomb intensified the cold war. Nuclear fusion leads to hydrogen bomb. The world is facing a mutually assured destruction (mad) till 1991 Fission Energy for War and Peace
Nuclear Reactors devices operating at steady-state chain reaction for research and power generation. Fission Energy for War and Peace
Key Components of Nuclear Reactors Reactor core (fuel): enriched or natural U, 239PuModerators graphite, H2O, D2O He (100 Atm and 1273 K) Be (high temperature liquid metal). Na (773 to 873 K for breeder reactor) BeF2 + ZrF4 ( for GCR)Control rods Cadmium, Boron, Carbon, Cobalt, Silver, Hafnium, and Gadolinium, c =255 kb for 157Gd Monitoring devices Neutron and radioactivity detectors, T, etc Energy transfer system Moderator or liquid Fission Energy for War and Peace
Types of Fission Reactors Fast Breeder Reactors (FBR) Aqueous Homogeneous Reactors (AHR) Heavy Water Moderated Reactors (HWR)Pressurized Water Reactors (PWR) Boiling Water Reactors (BWR)Organic-Cooled Power Reactors (OCPR)Sodium Graphite Reactors (SGR)Gas-Cooled Reactors (GCR) Fission Energy for War and Peace
Fast Breeder Reactors for Fission Fuel Production Fission Energy for War and Peace
Reactions in Fast Breeder Reactors (FBR) Fast Breeder Reactors produce more fission fuel they consume. Two types of product dependent FBR The 239Pu or uranium cycle 238U ( fast n, 2) 239Pu, c = 2.7 b The thorium cycle 232Th (slow n, ) 233U, c = 7.4 b, f = 5.6×10-5 b Fission Energy for War and Peace
CANDU Reactors CANadian Deuterium Uranium (CANDU) Reactors employ natural uranium for fuel and heavy water as moderator. Features:22 reactors supply 20% of electric power in Canada Bundles of fuel tubes loaded horizontallyReplace fuel during operation Use oxide of natural uranium as fuel and D2O as moderator Generate large volumes of nuclear wastesProduce 239Pu Fission Energy for War and Peace
CANDU 9 (900 MW) Reactors Fission Energy for War and Peace
Reactor accidents An accident is a series of undesirable events that took place due to accumulated causes. Costly Lessons comes from the understanding of full details of accidents. Nuclear accidents attract more attention due to release of radioactive nuclides. Radioactivity causes fear, because most people know little about it. Many nuclear accidents have happened. Fission Energy for War and Peace
TMI-2 3000 MW PWR Power Reactor Fission Energy for War and Peace
The TMI-2 Reactor Design Fission Energy for War and Peace
TMI-2 Reactor accidents Three Mile Island (TMI-2) was a pressurized water reactor (PWR) with a 3000 Mw capacity. March 28, 1979, two pumps failed to supply feed water steam generator. Valve of auxiliary pump was closed by error and auxiliary pump failed to operate. Pressure increased and relieve valves opened. Relieve valves failed to close resulting in a loss of coolant. Zircaloy-4 oxidized by water, producing a large volume of hydrogen gas. Core overheated resulting in meltdown Fission Energy for War and Peace
The TMI-2 Core After the Accident Four years later, photo image of TMI–2 core shows damage to its uranium fuel rods more extensive than originally thought just after he accident. Core meltdown shows the temperature reached 5000 K. Fission Energy for War and Peace http://washingtonpost.com/wp-srv/national/longterm/tmi/gallery/photo10.htm
Fission Products in the Core After the Accident Long-life Fission Products in the Core after TMI-2 Accident Isotope Activity /Ci Half-lifeAmount* 85K 9.7104 10.7 y 4.71013 90Sr 7.5105 28.8 y 9.81014 129I 2.210–3 1.6107 y 1.61012 131I 7.0107 8.04 d 7.01013 133Xe 1.5108 5.25 d 9.81013 137Cs 8.4105 30.2 y 1.11015 * Amount = Activityhalf-life (s)/0.693 Fission Energy for War and Peace
The Chernobyl Accident RBMK graphite-moderated, channel-tube-cooled reactors. Reactor 4 in Chernobyl had been in operation for 3 years prior to the accident. April 26, 1986, Reactor 4 at Chernobyl was scheduled for a safety test to see if residual power is sufficient to operate the reactor safely in case of a sudden power failure. Operators turned off cooling system and powered down. When power from the reactor failed to operate the reactor safely, they used power from the grid without notifying grid controller. Radioactivity of fission products overheat the core. When they turned up power with cooling system off, the core fragmented and exploded destroying the building. Radioactivity (fallout) spread to north Europe. Fission Energy for War and Peace
The Soviet RBMK Reactor Design The Soviet RBMK reactor has individual fuel channels, using ordinary water as coolant and graphite as moderator. It evolved from reactors designed for 239Pu production. Fission Energy for War and Peace
Natural Reactor Bouziques found low 235U abundance in uranium from Oklo, Gabon, West Africa and interpreted as a result of a natural fission reactor a long time ago. A large quantity of uranium ore concentrated and reached a critical size for a natural reactor. Found additional supporting evidences shown in the next frame. Fission Energy for War and Peace
Natural Reactor Location Fission Energy for War and Peace From: http://www.curtin.edu.au/curtin/centre/waisrc/OKLO/Where/Where.html
Additional Evidences for Natural Nuclear Reactor Isotope of Neodymium mass Natural Fission Oklo 142 27.11 0 0 143 12.17 28.8 25.7 144 23.85 26.5 29.3 145 8.30 18.9 18.4 156 17.22 14.4 14.9 148 5.73 8.26 8.2 150 5.62 3.12 3.5 The natural reactor released 15,000 MW-year energy for 150,000 years 1.8e9 years ago. Fission Energy for War and Peace
Nuclear Fission - Summary discovery of neutron-induced fission fission products, fission yields fission cross sections nuclear model for fission estimate (calculate) fission energy nuclear reactors, types, moderators, control rods enrichment of uranium and energy production using fission natural nuclear reactors reactor accidents and their impacts Fission Energy for War and Peace
Power Nuclear Reactors in the World nucleartourist.com/world/wwide1.htm Fission Energy for War and Peace