The radioactive products are concentrated in the used or spent fuel rods The

The radioactive products are concentrated in the used

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The radioactive products are concentrated in the used or spent fuel rods. The fuel rods are referred to as high-level nuclear waste . The half-lives of several of the products are very long, requiring special storage or disposal. Spent fuel rods can be reprocessed into new fuel rods. Reprocessing is not carried out in the United States due to regulatory concerns and nuclear nonproliferation treaties. All high-level waste is currently stored on-site at the reactor. On-site storage is not a long term solution.
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54 Nuclear Waste Yucca Mountain, in southwest Nevada, was proposed as the site for an extensive feasibility study for long term storage of high-level waste because it fulfills several general engineering considerations. Yucca Mountain is extremely remote, the climate is dry, and the water level is about 1000 feet below the potential burial vault. The storage facility must be remain intact for thousands of years. The construction materials will need to withstand the effects of high levels of radiation.
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55 Fusion In the sun, four hydrogen nuclei combine to form a helium nucleus, releasing energy in the process. The reaction of 4 protons is a stepwise process, too slow to be used in a nuclear reactor. The two heavier isotopes of hydrogen, deuterium ( 2 H) and tritium ( 3 H) can be fused to produce helium The reaction produces more energy per nucleus than fission. 4 1 1 H   2 4 He + 2 1 0 + 2 + energy 1 2 H + 1 3 H   2 4 He + 0 1 n
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56 Fusion Deuterium is naturally occurring; it makes up 0.015% of all hydrogen atoms. The available supply of deuterium is practically unlimited. Tritium can be produced from 6 Li. Fusion does not produce high-level radioactive waste. Energetic neutrons can induce nuclear reactions in reactor materials, producing some level of radioactivity. Risk minimized by careful choices of engineering materials. 3 6 Li + 0 1 n   2 4 He + 1 3 H
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57 Fusion During fusion, the repulsion of positively charged nuclei must be overcome. Fusion reactions initiated at temperatures on the order of 10 6 K. High temperature required to force nuclei close enough to overcome coulombic repulsion. The first application of fusion was the hydrogen bomb . A fission bomb initiated the fusion reaction. Controlled fusion must use a nondestructive means of initiation. As an energy source, fusion must release more energy than it requires as input.
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58 Fusion The fusion reaction must be confined somehow. Solid reactor materials would melt at the high initiation temperatures. Two promising means for solving the confinement problem. Magnetic confinement : The high-energy plasma produced at 10 6 K is controlled in a magnetic field. Inertial confinement : A pellet of fuel is dropped into a reaction chamber and imploded by high-energy lasers. So far, more energy is required to produce fusion than is released.
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59 Interaction of Radiation and Matter There are three factors governing the effects of radiation on matter.
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