MAAP and a Comparison of Physical Processes that Affect Containment Integrity

Containment integrity or the probability of an early containment failure is the key issue in. the event of a severe accident in a nuclear power plant. The possibility of an early contain- ment failure could be found by determining the containment temperature and pressure. histories and comparing them to those of the containment failure criteria. Hydrogen burn- ing, in-vessel melt holdup, and the entrainment of the corium into different compartments are of those physical processes that have the most significant effects on the containment integrity. The MAAP computer program was used to gain more qualitative understanding of the accident transients and the over all plant behavior. Sensitivity studies were per formed on the MAAP modelling of the Kewaunee nuclear power plant to estimate the relative effects of the above physical processes on the containment loading. There are un- certainties concerning some of the inputs in the MAAP model parameter file. This study examined only four of those parameters that were believed to have the most effects on the containment loading.