StartHistoryUse of the current
Power stationsAtomic energyAtomic energy....Mode of ope...(Dis)-AdvantagesThe waste pro...Water energySolar powerWind energyCoal/oil/gas...ElectricityMillenium BugFutureWWW-Board
| The waste product | |
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With the arrears, which develop from the nuclear fission, one measures the time,
until the radioactive radiation amounts to only half. We call this radioactive
half-life and this is with each material different. For example iodine-131 has a radioactive half-life of 8 days and plutonium-239 has one of 24000 years. The gaseous fission products are led into an exhaust system and held back there until the radioactivity of these gases contains only a small fraction of the original. Liquid wastes, like the cooling water, are caught and cleaned in special containers. Afterwards the water can be transferred problem-free to the rivers. With the fixed arrears one differentiates between short-lived weak and medium-active, long-lived medium-active and strong-active wastes. |
 The waste productThe disposalIn the reprocessing plantDumping |
| The disposal | |
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The short-lived low-activity wastes, in addition insulating material, paper, belongs tools etc., are burned in a special system and filled into iron barrels. The arrears of the cleaning systems are short-lived active. They are likewise filled up into iron barrels and solidified additionally with concrete or plastic. The short-lived wastes are stored first in the temporary storage facilities in the power station and arrive from there in the ultimate waste disposal. In a nuclear power station only about 1% of the developed wastes are short-lived weak or medium active. Over 99% of the radioactivity remains in the fuel elements and is long-lived medium or strong active. The fuel elements remain at least 6 months in the atomic power plant, until they deliver no more warmth. Afterwards they are transported in 120 tons special containers into the reprocessing plant. |
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| In the reprocessing plant | |
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First the fuel elements are kept three years in storage pool. In this time the radioactive substances disintegrate still more. Now the fuel rods are cut open and resolved in a chemical process. The two items uranium and plutonium (a newly developed fissile item) are separated chemically. One uses these two materials for the production of new fuel elements. The materials, which is not used anymore, one stores further a year in liquid form. Thus the radioactivity disintegrates still more. In a second step the arrears are glassed with a chemical process. These 1.5 meters high steel cylinders can be stored problem-free during decades in temporary storage facilities, until they are transferred in the ultimate waste disposal. |
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| Dumping | |
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With the long-lived medium and strong-active wastes one must be very safe that no water can penetrate to them, in order to get thereafter the environment dirty. One switches therefore as much as possible, from each other independent safety barriers on. First the arrears are glassed and filled into steel cylinders. Afterwards this cylinder is put into corrosion-resistant containers. As the third step one coats this container with a material that is as water-resistant as possible. After everything the container is stored in geologically sturdy and waterproof rock. Over the enclosed container one pours to the termination still several hundred meters rock. In order to arrive at the stocks silos (which is about 500 - 1500 meters under the earth's surface), one bores slots, in which the containers are transported. As the short-lived weak and medium active material disintegrating much faster, one must pack these not in such a way like the long-lived arrears. To the barrels filled with wastes one gives so-called binding agent, which bind the radioactive substances. Afterwards the barrels in containers are summarized and surrounded with cement. The container is filled up with concrete and stored in the ultimate waste disposal in at least 100 meters under the earth's surface. |
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| Da die kurzlebigen schwach- und mittelaktiven Stoffe viel schneller Zerfallen, muss man diese nicht so verpacken wie die langlebigen Rückstände. In die mit Abfällen gefüllten Fässer gibt man sogenannte Verfestiger, welche die radioaktiven Stoffe binden. Danach werden die Fässer in Container zusammengefasst und mit Zement umgeben. Als nächstes schliesst man die Container in Beton ein und lagert sie im Endlager in mindestens 100 Metern unter der Erdoberfläche. |
Atomic energyMode of ope...(Dis)-AdvantagesThe waste product |
| Power stations: Atomic energy: The waste product |
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A ThinkQuest Project by Team 26663 |