Ermittlung von Strahlendosen in der Umgebung des THTR-300 infolge eines angenommenen Coreaufheizunfalls
Ermittlung von Strahlendosen in der Umgebung des THTR-300 infolge eines angenommenen Coreaufheizunfalls
The radiation doses to be expected in case of a hypothetical accident in the surroundings of the THTR-300 have been calculated. Moreover the period of time available for countermeasures has been estimated. These data make possible the rational planning of adequate emergency countermeasures. As a cha...
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Personal Name(s): | Fassbender, J. |
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Kröger, W. / Rehm, W. / Wolters, J. / Verfondern, Karl / Geiss, H. | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Kernforschungsanlage Jülich GmbH Zentralbibliothek, Verlag
1984
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Physical Description: |
27 p., Anh. |
Document Type: |
Report Book |
Research Program: |
ohne Topic |
Series Title: |
Spezielle Berichte der Kernforschungsanlage Jülich
275 |
Link: |
OpenAccess |
Publikationsportal JuSER |
The radiation doses to be expected in case of a hypothetical accident in the surroundings of the THTR-300 have been calculated. Moreover the period of time available for countermeasures has been estimated. These data make possible the rational planning of adequate emergency countermeasures. As a characteristic accident sequence causing the maximum consequences, a sudden irreparable loss of core cooling at full power was assumed. This causes a slow increase in the temperature of the reactor core and the coolant gas pressure. In addition it is assumed that the gas cleaning plant fails, and that the safety valve does not shut again after it has been opened by the rising coolant gas pressure 8 hours after the initiation of the accident. This sequence of events results in a slow loss of coolant gas accompanied by an unfiltered release of radioactivity through the stack lasting about two days. The expected frequency of such an accident is less than 10$^{-8}$/year. When the safety valve opens, mainly noble gases and iodine will be released at first. Cesium and strontium only follow after more than 30 and 50 hours, respectively. The radiation doses were pessimistically estimated on the basis of the 'RSK/SSK-Störfallberechnungsgrundlagen' for an exposure time of 7 days. The thyroid dose nowhere exceeds 25 rem (lowest hazard class of the "Rahmenempfehlungen" of the Federal Ministry of the Interior), if the consumption of contaminated food is forbidden within 8 hours after the beginning of the accident. The whole body dose is mainly caused by the inhalation of strontium. It does not exceed 5 rem and therefore does not reach the upper limit of the lowest hazard class by far. This is also true of the bone dose. The estimated doses are to be considered as a kind of upper limit values which in case of a real accident would not be reached by far. In any case the development of the accident leaves ampletime for an analysis of the accident situation, the measurement of the actual radiation, and the initiation of adequate countermeasures. |