Analyses of large scale tests addressing the performance of a containment cooler and its effect on gas distribution

The performance of containment coolers and their effect on the hydrogen risk in the case of an accident with core overheat is an issue that needs to be addressed by means of simulation tools. Four tests performed in the PANDA facility within the OECD SETH 2 project provide a new database to evaluate the capability of the codes to predict the cooling effectiveness of a cooler and its effect on flow patterns and light gas distribution. All tests have been simulated with the GOTHIC code using a three-dimensional mesh and a rather detailed model for the cooler tube bundle. In general, the results obtained are in reasonable agreement with the data, although some major discrepancies have also been observed, which are mostly due to the limited detail permitted by the relatively coarse mesh adopted for all tests of the SETH 2 project. (author)