Refinement of Siemens core monitoring based on aeroball and PDD in-core measuring systems using powertraxTM

The Siemens/KWU core monitoring concept is consistently based upon two complementary in-core instrumentation systems, Aeroball and PDD. The Aeroball system is a fast, high resolution measuring system used for reference purposes. The PDD system yields continuous local power density data in three dimensions that feed directly into the margin calculators for maximum linear heat generation rate and minimum DNB ratio of the automatic Power Density Limitation System. This standard core monitoring concept can be refined and extended using POWERTRAXTM, a state-of-the-art PWR core monitoring software system. Coupling it to the in-core measurement systems enhances the transparency of core behaviour for the reactor operator, simplifies the interpretation of monitoring signals, supports the elaboration of optimised operating strategies, and permits the use of realistic margins for monitoring the limiting conditions for operation (LCO). (authors)