A critical review of the current PWR containment response analysis methodologies for postulated severe accident

The EVNTREISS code, used as a basis of the present work, is highly complex and versatile in comparison with the previous CET used in the WASH-1400 study. Since the construction of the EVNTREISS code is very complex and has not gone through a thorough validation and review process by an independent referee it is not surprising to find a few areas of improvement and several inherent problems of the code. The present study is thus initiated to identify all the problems and areas of improvement for the EVNTREISS code and modify the code according to the insights gained from the experience of reproducing the Zion containment response analysis performed at the Brookhaven National Laboratory. As a result of this study, several areas of improvement for the EVNTREISS code have been identified and a few problems of the code have been resolved in addition to the reproduction of the Zion results. Finally, the modified code can now be run by a personal computer and can be used in the analysis of a Large Dry PWR containment response for severe accidents. (Author)