Achievements and Status of Research Activities in the Containment Area

In the SARNET Containment topic three issues of severe accident phenomenology are treated which endanger the containment integrity in an early stage of the accident by pressure increase due to fast heat transfer: hydrogen combustion, explosive melt water reaction, and direct containment heating. Progress in activities dealing with the hydrogen issue was achieved by performing experiments addressing these subjects: - hydrogen combustion with defined concentration gradients, - hydrogen mitigation via recombiners and the issue of self-ignition within a recombiner, - thermal-hydraulic phenomena in the containment (steam injection, condensation, sprays), - interaction between Passive Autocatalytic Recombiners and containment atmosphere. The experimental results are being used for benchmark simulations with both lumped parameter codes and CFD codes. The modeling results were discussed in numerous workshops with focus on large scale application. The experimental progress concerning the Fuel-Coolant Interaction (FCI) issue was delayed by the relocation of the KROTOS test facility to CEA, Cadarache. Calculation work in preparation of the planned tests was performed by several partners with different CFD codes. Based on existing experimental data the issues of material effect (alumina ¿ corium) and specific melt entry conditions are being investigated by code calculations. Concerning the Direct Containment Heating issue (DCH) a significant database has been established for different European reactor plants. Benchmark exercises have identified promising modeling approaches in the CONTAIN code but also revealed necessary improvements in modeling in ASTEC.

MEYER Leo;  WILKENING Heinz;  KLJENAK Ivo;  MAGALLON Daniel; 

2013-03-19

IRSN

JRC43162