THE IC MODERNIZATION PROJECT OF THE NPP LEIBSTADT - LESSONS LEARNED FROM THE FIRST MODERNIZATION STEP

摘要

The Swiss Nuclear Electricity Production consists of four sites with a total of 5 Reactors. Together they have a capacity of 3220 MW and cover about 40% of the total Swiss Electricity production. Leibstadt is the first Swiss NPP which performs a comprehensive modernization project of all process related I&C equipment in regard of an intended operation at least until 2045. The project will take more than 15 years since the implementation will be only possible stepwise during the scheduled outages.The first modernization step, which comprised mainly the replacement of the former stand alone process computers including the Safety Parameter Display System SPDS by a common platform, was functionally finished in the outage 2006 with a delay of 2 years over the original target line. But it still left open the upgrade of the platform to the targeted system version which was significantly delayed by the system supplier. This upgrade was finally accomplished during the outage 2008.The platform now conforms to a full blown integrated Plant Information Systems with all relevant applications and functions but above this, it forms already the operating & monitoring level of the future integrated process control system for the operational as well as the safety I&C.With each of the upcoming further modernization steps, parts of the process level will be added to the digital system resp. platform by replacing the existing analog equipment for signal interrogation, component control and automation functions like sequencer or switchover functions.The paper deals on with the operational experience between 2006 and 2008 and the measures which became necessary due to problems and flaws in the system behaviour. Also the operational experience with the upgraded system since the outage 2008 will be compared to the previous experience. The central content of the paper will be the strategy for the upgrade of the platform, the execution of it as well as enhancements of the platform in lieu of the upcoming modernization steps. Furthermore extensions of the system due to modifications and new processes in the plant will be shown. This paper is a continuation of the paper presented at the ANS Meeting in 2006.