Advanced NuclearPower - AREVA

Projects & EngineeringBeznau: Upgrading I&C withTELEPERM XSFramatome ANP has upgraded the entire reactor protection system at a Westinghouse-built plant with digitalinstrumentation and control (I&C) equipment. The successful upgrading of both units of Switzerland’sBeznau nuclear power plant once again has impressively demonstrated why Framatome ANP is the world leaderin modernizing reactor I&C. In the last 10 years, the company has won well over half of all I&C modernizationcontracts awarded worldwide – an impressive customer vote of confidence – for the digital safety I&C platform,TELEPERM XS, that is currently in use or on order at 23 reactors, including PWRs, BWRs and VVERs,in seven countries.Fit for the Future withTELEPERM XSBy deciding to upgrade the I&Cequipment for reactor scram andengineered safety feature actuation, thecompany that operates Beznau –Nordostschweizerische KraftwerkeAG (NOK) – took an important steptowards ensuring that the plant reflectsthe latest state-of-the-art technologyand can operate economically formany years to come. Replacement ofthese systems had become necessaryas spare parts procurement and componentmaintenance were becomingincreasingly difficult. Anotheraim was to improve ease of testingequipment.In TELEPERM XS, Beznaunow has a digital safety I&C platformthat is fully qualified for nuclearapplications. Other key features includelow inspection and maintenance, andoptimized diagnostics capabilities.Scope of the ProjectThe contract for backfitting BeznauUnits 1 and 2 with new safety I&Cequipment was awarded by NOK in1998. The following enhancements weremade along with installing the newequipment:• Significantly better fault diagnosisin the safety I&C systems• Stricter physical separation ofredundant trains, andBeznau Units 1 and 2 each have an electric output of 380 MW. The first unitstarted commercial operation in 1969 and the second in 1971.• Functional improvements toclosed-loop controls.The former operating and monitoringconcept was retained, meaning thatoperating personnel were not facedwith significant changes.The new safety I&C equipmentis designed with quadruple redundancyand physical separation of all redundanttrains, with the individual safetyfunctions of each train being furtherdivided among two so-called DiversityGroups (A and B). Also, each trainhas two independent TELEPERM XScomputers: one for Diversity Group Aand another for Group B.The new closed-loop controls forthe reactor are of dual redundancy.Key Steps of the Project:From Designing to Installationand StartupIn accordance with Swiss regulatoryguides, the project was divided forboth plant units into four hierarchicallevels consisting of a basic design4 Advanced Nuclear Power N O 3 January 2002