Advanced Nuclear Power - AREVA

Mechanical EquipmentMechanical EquipmentNew Steam Generatorsfor Prairie IslandOn August 11, 2000, Northern StatesPower Company (NSP) awardedFramatome ANP a contract for tworeplacement steam generators (RSG)at the Prairie Island Unit 1 nuclear station.Prairie Island Unit 1 is a 530MWe plant owned by Xcel Energy,created later by the merger ofMinneapolis-based NSP and DenverbasedNew Century Energies, andoperated by Nuclear ManagementCompany (NMC) of Hudson,Wisconsin. Prairie Island is located onthe Mississippi River 40 miles (70km)southeast of Minneapolis, Minn. Thesite includes two identical units thatbegan operating in 1973 and 1974.Delivery is scheduled for early2004 with installation in the fall of2004. The new steam generators willbe delivered in two pieces with thefinal weld assembly and installationperformed on site by the SteamGenerating Team (SGT) LLC (a USbased changeout company), which wasawarded a separate contract for thiswork. Framatome ANP in Lynchburgwill perform the licensing analysis.The anti-stratification helix andloose part trapping systems(Framatome ANP patents) proposedas options have been selected. Thesesystems help increase plant availabilityand reliability and reduce maintenancecosts.An integrated team consisting ofFramatome ANP global organizationsin the US and France for licensing,engineering, and the Chalon SaintMarcel plant for procurement, manufacturingand transport to the site, hasbeen set up for this project. Procurementshave been scheduled so thatmanufacturing can begin in December2001. As a result, plan pre-productionreview meetings with main suppliers(forgings, tubing…) will begin withinthe next months. Manufacturing activitieswill be surveilled by an NMCQuality representative at FramatomeANP’s Chalon Saint Marcel plant.Xcel Energy, Inc. outlined stringentrequirements regarding the deliveryschedule and the steam generator tubingquality. To ensure that all steamgenerators manufactured at theChalon Saint Marcel facility not onlymeet exacting customer specifications,but are the best and most error free inthe world, Framatome ANP• stringently restricts access to cleanareas on the shop floor• maintains diligent foreign materialexclusion (FME) that restricts access toclean rooms used for tubing installationsequences• created 15 separate working groupsin specific areas for the US market:Primavera scheduling, US units, webserver, notification, documentation,distributionBy using a fully integrated teamconcept, stringent plant controls andpractices, and the cooperation of allinvolved partners, the success of thesteam generator replacement forPrairie Island can be assured. @Chalon Saint MarcelManufacturing FacilityTotal number of NSS components444 (RPV+SG+PZR)- 85% for domestic market- 15% for export marketHuman resources : 500 peopleBenefits of Framatome ANPReplacement Steam Generators- 9% uprate capability (from 825 MWth/SG up to 900 MWth/SG)- Maintenance of required steam pressure even in end of lifeconditions (plugging margin and design fouling)- Moisture carry-over lower than 0.10%- Inconel 690 TT corrosion resistant tubing and excellent tube bundlevibration behavior for trouble-free operation- Thermal stratification effects mitigated due to the antistratificationhelix- Stainless steel feedwater distribution system to prevent erosioncorrosion risks- Feedwater distribution system design in accordance with the NRCBranch Technical Position 10-2 preventing any water hammer risks- Excellent water level stability to minimize risk of spurious trips- Steam flow restrictor and loose part trapping systems toimprove safety- Channel head design to improve peripheral tubes access- Tube size and tube bundle arrangement compatible withexisting toolsChalon Saint Marcel is the world’s leadingsupplier of nuclear components.Shown here is the subassembly equipmentbay.Products : RPV, SG, PZR,internals, tanks and supportstructures16 Advanced Nuclear Power 08/200108/2001 Advanced Nuclear Power 17