Publikationsserver der RWTH Aachen University
Thermisches Versagen von Reaktordruckbehältern bei extremen Störfällen in Druckwasserreaktoren : Analyse und Verbesserungsvorschläge
Abstract
dc:descriptionThis thesis served to investigate the behavior of the pressure vessel in serious reactor accidents. To this end, a reference case for a conservative accident scenario was initially defined then modeled with the FEM software ANSYS. Calculations done with this software were used to analyze the behavior of the pressure vessel in the reference case up to the point that thermal failure would occur.Due to the high uncertainty involved in the complex accident sequence, several analyses beyond reference case calculation were conducted in order to determine the impact of changes in vital parameters up until the vessel's thermal failure. Calculation results show that the thickness of the corium crust – which develops in the early stages of the accident – has significant impact on the time to failure. Other vital parameters are the amount of after-heat power and the emission of heat from the pressure vessel's outer wall (thus, the cooling conditions at the outer wall).Based on these results, several ideas were generated to extend the time to failure and analyzed independently from each other: reducing the amount of after-heat power, optimizing cooling conditions at the pressure vessel's outer wall (cooling with water, cooling with lead), and inserting a protective ZrO2 layer that would fulfill a similar function as the corium crust.Results from these analyses show that implementing these measures can extend the time up until failure significantly. However, vessel failure – thus the penetration of corium into the containment – probably cannot be prevented completely.In this work, the technical definition and design of the improvement measures were not investigated in detail. Nor were any implications for the plant of implementing these measures (e.g., implementation cost, impact on normal mode). In addition, mechanical vessel failure mechanisms could not be considered. Therefore, the implementation of the suggested improvement measures requires further detailed investigations. In parallel and in addition to further calculations, experiments need to be carried out in order to validate simulation results.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2005
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Heuss, Ruth
- Contributors dc:contributor
-
- Kugeler, Kurt
Subjects
dc:subject × 7Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger