The study of the effectiveness of the emergency condenser of the BWR 600/1000 in the NOKO test facility

The BWR600/1000 is a new innovative passive boiling water reactor concept which is being developed by Siemens. The concept is characterized in particular by passive safety systems (i.e. four emergency condensers, four building condensers, eight passive pressure pulse transmitters, six gravity-driven core flooding lines, eight rupture disks arranged in parallel to the relief valves and two scram systems). For experimental investigations of the effectiveness of the emergency condenser the NOKO test facility has been constructed at the Forschungszentrum Juelich in cooperation with Siemens. This project is sponsored also by the BMBF and some German Utilities. The test phase started in early 1995. The NOKO facility has a maximum operating pressure of 9 MPa and maximum power of 4 MW for steam production. The emergency condenser consists of 8 tubes and is fabricated with original geometries and materials. The objectives of the experiments are the study of the effectiveness of the BWR600/1000 emergency condenser under all expected conditions and (including non-condensibles), the use of the experimental data for computer code validation and model improvements. Some results from the start-up phase will be given. After finishing the emergency condenser test series several other components (e.g. building condensers and passive pressure pulse transmitters of the BWR600/1000) shall be tested in the NOKO facility. Because of the multi-purpose design of the NOKO test facility only few reconstructions are necessary for other designs. (author). 9 figs