In order to assist control room staff of failure of any electrical or mechanical component a new objects-oriented-database-system (OODBS) has been developed and installed. Monitoring and diagnostics may be supported by this OODBS within a well-defined response time. The operator gets a report on different levels: For example, at a first level data about the vendor of a device (like reactor vessel internals, pumps, valves, etc.), data of installation, history of failures since installation, at a second level e.g. technical data of the device, at a next level e.g. a scanned photo of the device with its identification number within a certain compartment, and at another level using a CAD-system presenting technical drawings and corresponding part lists in order to assist necessary communication between operator and maintenance technician. (author). 3 refs, 10 figs.