Recently developed KWU systems for monitoring fatigue, vibrations, leakages and loose parts in reactor circuits

Monitoring systems are based on complex and high technology methods and - in the past - needed the full skill of well-trained engineers. A new generation of systems has been developed over the last five years by Siemens/KWU. It is based on microprocessors of the Intel 80186/80286 family. The new systems improve the reliability and quality of the surveillance techniques, relieve effort and reduce the number of staff needed for maintenance and evaluation. The paper gives an overview of four monitoring systems and explains their principal features and objectives. These systems are part of an overall concept of assuring the integrity of the primary coolant system of nuclear power plants. Their functions include acquisition, processing, storage and documentation of the necessary data and also provision of the other aids required for quick and reliable analysis. All systems follow a common technical concept in which autonomous modular individual systems perform identical functions (root mean square generation, calibration, analogue - digital conversion, filtering, etc.) with identical modules. For analyses exceeding the microprocessors' capacity, compressed data records may be transferred to a host computer, even using long distance data transmission. Requirements concerning vibration, loose parts and leakage monitoring are part of Federal German guidelines and safety standards. Therefore, systems for these applications are implemented in most nuclear power plants in the Federal Republic of Germany, whereas the fatigue monitoring system is the result of more recent research and development by KWU. This system will be implemented for the first time in the new KWU 'Convoy' plants. The four monitoring systems are designated as 'Series '86'. With respect to the man-machine interface it should be mentioned that all essential functions of the Series '86 monitoring systems are performed automatically; event detection, alarm data acquisition and evaluation, documentation, long term statistics, test routines and status check. Thus the work loan on the operating personnel is reduced to initial system adjustment and man-machine dialogue evaluation. (author). 16 refs, 8 figs