EPR – Areva brochure

PLANT OPERATION,MAINTENANCE& SERVICESPLANT OPERATION, MAINTENANCE& SERVICESFrom the beginning, the EPR and its equipment and systems have been designed to allow for efficientrefueling outages and to simplify and optimize inspection and maintenance in order to increase plantavailability and reduce maintenance costs, two major objectives of plant operators worldwide to meet thedemands of more and more competitive power markets.Neckarwestheim nuclear power plant (Germany):unit 2 (right foreground) is of the KONVOI type(1,300 MWe).A 92% AVAILABILITY FACTOROVER THE ENTIRE PLANT LIFE page 55A HIGH LEVEL OF OPERATIONALMANEUVERABILITY page 56AN ENHANCED RADIOLOGICALPROTECTION page 56PLANT SERVICES page 56CONTINUOUSLY IMPROVINGSERVICE TO CUSTOMERS page 57A 92% AVAILABILITY FACTOR OVERTHE ENTIRE PLANT LIFERegarding availability, the EPR is designed to reach 92% over theentire 60 years of its design lifetime. This is made possible by shortscheduledoutages for fuel loading/unloading and in-serviceinspections and maintenance, and also through reduced downtimesattributable to unscheduled outages.The high degree of equipment reliability on the one hand, and thedecrease in reactor trip causes (in particular due to the deploymentof the limitation system related to reactor operation) on the otherhand lead to an unscheduled unavailability not exceeding 2%.The quadruple redundancy of the safeguard systems allows a largepart of the preventive maintenance operations to be performed whilethe reactor is at power.Moreover, the reactor building is designed to be accessible, understandard safety and radiation protection conditions, while the reactoris at power. This enables the outage and maintenance operationsto be prepared and demobilized with no loss of availability. Thispossibility of access with the reactor on line also facilitates fieldservices which could be needed outside scheduled outage periods.Based on experience feedback, standardization and ease of accessof the components of the reactor allow simple and rapid performanceof inspection and maintenance work.Access to the reactor building during power operation allows to startpreventive maintenance and refueling tasks up to seven days beforereactor shutdown and to continue their demobilization up to threedays after reactor restart.The duration of the plant shutdown phase is reduced by a time gainfor reactor coolant system cooldown, depressurization and vesselhead opening. Similarly the length of the restart phase is reducedas well and benefits from the reduction in the time needed to runthe beginning-of-cycle core physics tests (gain supplied by the“aeroball” in-core instrumentation system). Durations of about 70and 90 hours are respectively scheduled for the shutdown andrestart phases. For the fuel loading/unloading operations, a timeperiod of about 80 hours is scheduled.† Duration of a regular outage for preventive maintenance andrefueling is reduced to 16 days. Duration of an outage forrefueling only does not exceed 12 days. Decennial outages formain equipment in-service inspection, turbine overhaul andcontainment pressure test are planned with a 38-day duration.Chooz B1, France (N4, 1,500 MWe): removal of the hydraulic section of a reactor coolantpump for maintenance.The EPR is designed to:† maximize plant availability andmaneuverability,† ease operation and maintenanceand reduce their costs,† enhance radiological protectionof the personnel,† protect the environment and contributeto a sustainable development.54 II 55