Focus of our working group’s activities are analyses regarding the simulation and safety of nuclear power plants as well as the evaluation of the necessary instruments.

As instruments international system codes are used and validated. Moreover, contributions to their improvement are made.

In order to realise comprehensive analyses for power plants or individual subsystems it is required to use these calculation programmes, which enable a preferably realistic simulation (best estimate) of the processes and the possible conditions according to the state of the art, especially during an accident, also by operating companies, manufacturers and licensing authorities. Next to their main function as a simulation tool, they also offer a knowledge pool for accident analyses.

The international severe accident analysis codes rely on the constant updating of the used models and methods according to the latest findings in research on the one hand and on the other hand as a result of extensive analyses within the scope of operating with and validating the programme.

The analysis of selected detail mechanisms of thermo- and fluid dynamics with safety-relevant phenomena, such as hydrogen deflagration, water hammer or the quenching of high heat-treated structures, is also conveyed via CFD-simulations.
Besides the use of commercial CFD-programmes, the focus is on the application and advancement of open source software.
Long term goal is the development of a comprehensive CFD-software for safety research.

Individual PSS research activities are:

• Advancement, optimisation and validation of international severe accident analysis codes and their physical model basis,
• Accident analyses and opportunities for accident prevention (Severe Accident Management Guidelines (SAMGs)),
• Generation of data sets concerning the simulation of European power plant types,
• CFD analyses,
• Examination of current incidents.

Simulation of hydrogen combustion

Simulation of core degradation in a boiling water reactor