LESSON PLAN ULBER 2 1, Introduction: . of, atonic“phenomena, This is to. fandarize you with certain aspects rn 2. Types.of Atomic Bursts: 3, Air Burst: ‘Je shall first consider the different "types of atomic bursts,Abomd may be dropped to explode in -the air air burst), to explode at the first contact with the surface (a surface ‘ burst) and'to explode underground (a sub-surface burst). * We shall consider the air burst in most detail and study the tivo other types by comparison, 'Using a overhead projector instru will show diagrams on pages 27 to 31, Volume II, Radiological Defense Manual, to illustrate his description of an air burste material presented beneath each illustration), - - aa lk. eee Sub-Surface Burst: By comparison a sub-surface burst will result: in the formation of a large crater, Earth or water will be hurled upwards, may weigh over a million tons, and a surge of radiological dust or water will form, There will be a strong ground shock wave through the ground ��or water similar to a moderate earthquake, The imsediate thermal and nuclear radiations are essentially absorbed by the ground’ orwater but the radiation emitted by active particles carried by the dust or water droplets will be intense, - A considerable "fall out" will be expected, ~ 5. bh He will cover the Surface Burst: The charactcristics of a surface burst and a sub-surface burst will lie between those of an cir burstand a sub-surface burst. Energy will go both into air blast and ground shocks. The thermal and immediate nuclear radiations will be similar to those in an air burst, The surge of dust or droplets will be less than for a sub-surface burst, However, it will still result'in an appreciable fall out. (Show figures on page 48, to 52, Volume II), 6. Thus we see that a surface burst and a sub-surface burst both: leave a considerable radiation hazard, much greater than that which we would expect from an air burst, . The fission fragments and any induced activity resulting fromthe strong neutron flux that is ‘present is trapped in the earth or water, carried up with the explosion, and is blom by the rind in heavy concentrations and causes a radiological problem, wherever it falls, . , . It is a danger . te “Contanination: if thére'were no wind, contaminate 1 areas vould. lie in a series of concentric rings or cirsles. around the point or area of burst, with decreasing contamination as vie go out on the radius of the circle, With a wind, this contamination is blawm dom wind and the rings or circles become elongated elipses, Naturally you can be much closer to the blast upwind and be free of contamination than vou can downwind, (Show figure 4.41, page 57 Volume IL),

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