[en] The safety concept of the innovative boiling water reactor SWR 1000 is characterised by passive safety systems (e.g. emergency condensers, building condensers, passive initiators). The operation mode and the effectiveness of these safety systems are investigated in the multipurpose thermal hydraulic test facility NOKO at the Forschungszentrum Juelich. The effectiveness of the emergency condenser was determined in more than 200 experiments. Post test calculations of the emergency condenser experiments were performed with an improved version of the ATHLET code. The comparison of the calculations and the experiments shows a good agreement. In parallel, the performance of three different designs of the passive initiator was investigated experimentally. The experimental results are used to optimize the design of an additional passive initiator, which will be tested in NOKO this year. Additionally, more than 80 experiments were carried out in NOKO to determine the effectiveness of two different designs of the building condenser. Post test calculations were performed using the modified computer code RALOC. The comparison of the calculations and the experiments shows a good agreement. (author)