Computational Validation of the EPRTM Combustible Gas Control System
During a postulated severe accident in a pressurized water reactor which involves the melting of the reactor core, hydrogen is released into the containment. In order to limit the pressure and temperature loads in case of a possible combustion of hydrogen and to prevent a challenge to the containment integrity, the EPRTM containment is equipped with a combustible gas control system. The multi-step approach for analytically validating the performance of this system is presented. The starting point for the analysis is a study of a large number of core melt accidents using a lumped-parameter code, which yields the release characteristics from the primary circuit into the containment. Based thereupon, a set of representative scenarios and bounding scenarios is selected for numerical calculations with both a lumped-parameter code and a computational fluid dynamics code, which yield the detailed distribution of the hydrogen in the containment, the depletion of hydrogen by recombiners, and the risk of the occurrence of potentially hazardous combustion modes. For cases where flame acceleration after hydrogen ignition cannot be ruled out by simple criteria, additional calculations with a dedicated computational fluid dynamics combustion code demonstrate that a transition from deflagration to detonation in the containment can be excluded. It is also shown that the temperature and pressure loads remain within the acceptable limits. Furthermore an in-depth analysis of the individual recombiner performance and methods for optimizing hydrogen depletion by the arrangement of the recombiners in the containment is presented. The potential impact of an early activation of the spray system on the hydrogen risk is also discussed.
Nuclear safety severe accident hydrogen combustion containment analysis flameacceleration
Harald Dimmelmeier Jürgen Eyink Mohammad-Ali Movahed
AREVA NP GmbH Paul-Gossen-Strasse 100, D-91052 Erlangen
国际会议
上海
英文
2596-2608
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）