ML14139A011

St. Lucie, Unit 1 - Report of 10 CFR 50.59 Plant Changes

ML14139A011
Person / Time
Site:	Saint Lucie
Issue date:	05/06/2014
From:	Katzman E S Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2014-125
Download: ML14139A011 (14)

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wMay 6, 2014L-2014-12510 CFR 50.59(d)U. S. Nuclear Regulatory CommissionAttn: Document Control DeskWashington, D. C. 20555Re: St. Lucie Unit 1Docket No. 50-335Report of 10 CFR 50.59 Plant ChangesPursuant to 10 CFR 50.59(d)(2), the enclosed report contains a brief description of anychanges, tests, and experiments, including a summary of the 50.59 evaluation of eachwhich were made on Unit 1 during the period of April 22, 2012 through November 9,2013. This submittal correlates with the information included in Amendment 26 of theUpdated Final Safety Analysis Report to be submitted under separate cover.Please contact us should there by any questions regarding this information.Sincerely,Eric S. KatzmanLicensing ManagerSt. Lucie PlantESK/tltEnclosure1:jZ7E4-Florida Power & Light Company6501 S. Ocean Drive, Jensen Beach, FL 34957 St. Lucie Unit 1 L-2014-125Docket No. 50-335 EnclosureST. LUCIE UNIT 1DOCKET NUMBER 50-335CHANGES, TESTS AND EXPERIMENTSMADE AS ALLOWED BY 10 CFR 50.59FOR THE PERIOD OFAPRIL 22, 2012 THROUGH NOVEMBER 9, 2013(13 PAGES INCLUDING COVER)I St. Lucie Unit I L-2014-125Docket No. 50-335 EnclosureINTRODUCTIONThis report is submitted in accordance with 10 CFR 50.59 (d)(2),which requires that:i) changes in the facility as described in the SAR;ii) changes in procedures as described in the SAR; andiii) tests and experiments not described in the SARthat are conducted without prior Commission approval be reported to the Commission inaccordance with 10 CFR 50.90 and 50.4. This report is intended to meet these requirements forthe period of April 22, 2012 through November 9, 2013.This report is typically divided into three (3) sections. First, changes to the facility as describedin the Updated Final Safety Analysis Report (UFSAR) performed by a Permanent Modification.Second, changes to the facility/procedures as described in the UFSAR, or tests/experiments notdescribed in the UFSAR, which are not performed by a Permanent Modification. And third, asummary of any Fuel Reload 10 CFR 50.59 evaluation.Sections 1, 2 and 3 summarize specific 10 CFR 50.59 evaluations that evaluated the specificchange(s). Each of these 10 CFR 50.59 evaluations concluded that the change does not require achange to the plant technical specifications, and prior NRC approval is not required.2 St. Lucie Unit 1Docket No. 50-335L-2014-125EnclosureTABLE OF CONTENTSSECTION 1PERMANENT MODIFICATIONSPAGEEC 277049, REVISION 0EC 275043, REVISION 0SECTION 2PERMANENT REMOVAL OF ST. LUCIEUNIT 1 RCP 1A1 WHIP (CABLE) RESTRAINTSPERMANENT REMOVAL OF ST. LUCIEUNIT 1 RCP 1A2 WHIP (CABLE) RESTRAINTS10 CFR 50.59 EVALUATIONS5811NONESECTION 3FUEL RELOAD EVALUATIONSST. LUCIE UNIT 1 CYCLE 25 RELOADEC 277290, REVISION 0133 St. Lucie Unit IDocket No. 50-335L-2014-125EnclosureSECTION 1PLANT CHANGE / MODIFICATIONS4 St. Lucie Unit I L-2014-125Docket No. 50-335 EnclosureEC 277049, REVISION 0PERMANENT REMOVAL OF ST. LUCIEUNIT I RCP IAI WHIP (CABLE) RESTRAINTSSUMMARY:To allow for future maintenance of the reactor coolant pump the RCP 1Al, whip (cable)restraints shall be permanently removed. In addition to removing an interference thatimpedes the disassembly of the pump it will also reduce the radiological dose required toreinstall the 4-inch cables.The St. Lucie Unit I Construction Permit was issued on July 1, 1970 and an OperatingLicensing was licensed in March 1976. Prior to 1986, General Design Criterion (GDC) 4,"Environmental and Missile Design Bases," required that systems and components importantto safety be appropriately protected against dynamic effects, including the effects of missiles,pipe whipping, and discharge fluids, which may result in equipment failures. In accordancewith NRC Branch Technical Position ASB 3-1, plants for which construction permits weretendered before July 1, 1993, and operating licenses were issued after July 1, 1975, shouldfollow the guidance of Appendix B of ASB 3-1 (letter by A Giambusso, December 1972,General Information Required for Consideration of the Effects of a Piping System BreakOutside Containment") and also provide moderate energy piping failure analyses inaccordance with Branch Technical Position ASB 3-1. Accordingly, the original St. LucieUnit I design bases considered all dynamic effects (missile generation, pipe whipping, pipebreak reaction forces, jet impingement forces, compartment, sub-compartment and cavitypressurizations and decompression waves with the ruptured pipe) and all environmentaleffects (pressure, temperature, humidity, and flooding) resulting from arbitrary intermediatepipe ruptures.Circa- 1986, GDC 4 was revised to read:"Environmental and dynamic effects design bases. Structures, systems, and componentsimportant to safety shall be designed to accommodate the effects of and to be compatiblewith the environmental conditions associated with normal operation, maintenance,testing, and postulated accidents, including loss-of-coolant accident. These structures,systems, and components shall be appropriately protected against dynamic effects,including the effects of missiles, pipe whipping, and discharging fluids, that may resultfrom equipment failures and from events and conditions outside the nuclear power unit.However, dynamic effects associated with postulated pipe ruptures in nuclear power unitsmay be excluded from the design basis when analyses reviewed and approved by theCommission demonstrate that the probability of fluid system piping rupture is extremelylow under conditions consistent with the design basis for the piping."Consistent with the revision to GDC 4, on June 19, 1987, the NRC issued Generic Letter 87-11, Relaxation in Arbitrary Intermediate Pipe Rupture Requirements which finalized arevision to Branch Technical Position (BTP) MEB 3-1 of Standard Review Plan (SRP)5 St. Lucie Unit 1 L-2014-125Docket No. 50-335 EnclosureSection 3.6.2 in NUREG-0800. The revisions to BTP MEB 3-1 and SRP 3.6.2 eliminated alldynamic effects and all environmental effects resulting from arbitrary intermediate piperuptures. This action allows the elimination of pipe whip restraints and jet impingementshields placed to mitigate the effects of arbitrary intermediate pipe ruptures, and other relatedchanges.On October 30, 1990, the NRC accepted Topical Report CEN-367, "Leak-Before-BreakEvaluation of Primary Loop Piping in Combustion Engineering Designed Nuclear SteamSupply Systems, which was submitted for staff review by Combustion Engineering OwnersGroup (CEOG) letter dated November 20, 1987. FPL was a participating CEOG memberand St. Lucie Units 1 and 2 were included in the bounding analyses submitted.By letter to the NRC dated August 26, 1992, FPL proposed to eliminate the dynamic effectsassociated with high energy pipe rupture in the reactor coolant system piping from thelicensing and design bases of St. Lucie Units 1 and 2 by the application of leak-before-break(LBB) technology. This change to the licensing and design bases is permitted by revisedGDC-4 of Appendix A to 10 CFR 50.By NRC letter dated March 5, 1993, the staff concluded that since the St. Lucie Units arebounded by the CEOG analyses and the leakage detection systems are capable of detectingthe specified leakage rate, the dynamic effects associated with postulated pipe breaks in theprimary coolant system piping can be excluded from the licensing and design bases of the St.Lucie Units.The Unit 1 UFSAR was updated to incorporate the effects of the staff's approval. Section3.1.4 was revised to read:Due to the application of leak before break methodology to the RCS hot and cold leg piping,the dynamic effects of a loss of coolant accident do not have to be considered. A technicalevaluation was performed to demonstrate that the probability or likelihood of large pipebreaks occurring in the primary coolant loops is sufficiently low that they need not be adesign basis.UFSAR Section 3.6.2 was revised to include the following acceptance criteria:It should be noted that circumferential (guillotine) and longitudinal (slot) breaks in RCS hotand cold leg piping are no longer considered a design basis for GDC 4 (NRC acceptanceletter for leak-before-break). The primary loop piping is not susceptible to failure from theeffects of corrosion, water hammer, fatigue, brittle fracture or indirect causes such as missilesor failure of nearby components. As a result, the mechanical/structural loadings associatedwith the dynamic effects of a large hot or cold leg break need not be considered.The proposed permanent removal of the upper two 4-inch reactor coolant pump RCP IAIwhip (cable) restraints meets the acceptance criteria found in Generic Letter 87-11. Also asdocumented in NRC letter dated March 5, 1993, the NRC staff has concluded that since theSt. Lucie Units are bounded by the CEOG analyses and the leakage detection systems are6 St. Lucie Unit I L-2014-125Docket No. 50-335 Enclosurecapable of detecting the specified leakage rate, the dynamic effects associated withpostulated pipe breaks in the primary coolant system piping can be excluded from thelicensing and design bases of the St. Lucie Units. The permanent removal of the upper RCPlAl whip restraints meets the acceptance criteria of BTP 3-1, as contained in SRP Section3.6.2, in that absent the whip restraints the primary coolant system piping continues to meetthe applicable ASME Code design requirements.There are no Technical Specifications that address the restraints. However, as discussed inthe Safety Evaluation by the NRC on Leak-Before-Break (LBB) Technology, the acceptanceof LBB is based on a leakage detection system consistent with Regulatory Guide 1.45,"Reactor Coolant Pressure Boundary Leakage Detection Systems." Technical SpecificationSection 3/4.4.6.1 addresses the RCS leakage detection system and no changes to this sectionor any other section is required as a result of the removal of the cable restraints.A License Amendment Request is not required. The RCS whip restraints were installedduring initial construction of St. Lucie Unit 1 to mitigate the dynamic effects associate withpostulated RCS hot and cold leg piping breaks. In 1993 the dynamic effects associated withpostulated pipe ruptures in RCS hot and cold leg piping were excluded from the design andlicensing bases of St. Lucie Unit 1, as described in UFSAR Section 3.6. Because theproposed change does not require a change to the technical specifications and does not meetany of the criteria in 10 CFR 50.59(c)(2), the change can be made without obtaining a licenseamendment pursuant to 10 CFR 50.90.7 St. Lucie Unit 1 L-2014-125Docket No. 50-335 EnclosureEC 275043, REVISION 0PERMANENT REMOVAL OF ST. LUCIEUNIT I RCP 1A2 WHIP (CABLE) RESTRAINTSSUMMARY:To allow for future maintenance of the reactor coolant pump the RCP 1A2 whip (cable)restraints shall be permanently removed. In addition to removing an interference that impedesthe disassembly of the pump it will also reduce the radiological dose required to reinstall the 4-inch cables.The St. Lucie Unit 1 Construction Permit was issued on July 1, 1970 and an Operating Licensingwas licensed in March 1976. Prior to 1986, General Design Criterion (GDC) 4, "Environmentaland Missile Design Bases," required that systems and components important to safety beappropriately protected against dynamic effects, including the effects of missiles, pipe whipping,and discharge fluids, which may result in equipment failures. In accordance with NRC BranchTechnical Position ASB 3-1, plants for which construction permits were tendered before July 1,1993, and operating licenses were issued after July 1, 1975, should follow the guidance ofAppendix B of ASB 3-1 (letter by A Giambusso, December 1972, General Information Requiredfor Consideration of the Effects of a Piping System Break Outside Containment") and alsoprovide moderate energy piping failure analyses in accordance with Branch Technical PositionASB 3-1. Accordingly, the original St. Lucie Unit I design bases considered all dynamic effects(missile generation, pipe whipping, pipe break reaction forces, jet impingement forces,compartment, sub-compartment and cavity pressurizations and decompression waves with theruptured pipe) and all environmental effects (pressure, temperature, humidity, and flooding)resulting from arbitrary intermediate pipe ruptures.Circa- 1986, GDC 4 was revised to read:"Environmental and dynamic effects design bases". Structures, systems, and componentsimportant to safety shall be designed to accommodate the effects of and to be compatible withthe environmental conditions associated with normal operation, maintenance, testing, andpostulated accidents, including loss-of-coolant accident. These structures, systems, andcomponents shall be appropriately protected against dynamic effects, including the effects ofmissiles, pipe whipping, and discharging fluids, that may result from equipment failures andfrom events and conditions outside the nuclear power unit. However, dynamic effects associatedwith postulated pipe ruptures in nuclear power units may be excluded from the design basiswhen analyses reviewed and approved by the Commission demonstrate that the probability offluid system piping rupture is extremely low under conditions consistent with the design basis forthe piping."Consistent with the revision to GDC 4, on June 19, 1987, the NRC issued Generic Letter 87-11,Relaxation in Arbitrary Intermediate Pipe Rupture Requirements which finalized a revision toBranch Technical Position (BTP) MEB 3-1 of Standard Review Plan (SRP) Section 3.6.2 in8 St. Lucie Unit I L-2014-125Docket No. 50-335 EnclosureNUREG-0800. The revisions to BTP MEB 3-1 and SRP 3.6.2 eliminated all dynamic effectsand all environmental effects resulting from arbitrary intermediate pipe ruptures. This actionallows the elimination of pipe whip restraints and jet impingement shields placed to mitigate theeffects of arbitrary intermediate pipe ruptures, and other related changes.On October 30, 1990, the NRC accepted Topical Report CEN-367, "Leak-Before-BreakEvaluation of Primary Loop Piping in Combustion Engineering Designed Nuclear Steam SupplySystems, which was submitted for staff review by Combustion Engineering Owners Group(CEOG) letter dated November 20, 1987. FPL was a participating CEOG member and St. LucieUnits 1 and 2 were included in the bounding analyses submitted.By letter to the NRC dated August 26, 1992, FPL proposed to eliminate the dynamic effectsassociated with high energy pipe rupture in the reactor coolant system piping from the licensingand design bases of St. Lucie Units I and 2 by the application of leak-before-break (LBB)technology. This change to the licensing and design bases is permitted by revised GDC-4 ofAppendix A to 10 CFR 50.By NRC letter dated March 5, 1993, the staff concluded that since the St. Lucie Units arebounded by the CEOG analyses and the leakage detection systems are capable of detecting thespecified leakage rate, the dynamic effects associated with postulated pipe breaks in the primarycoolant system piping can be excluded from the licensing and design bases of the St. LucieUnits. Furthermore by NRC letter dated July 9, 2012, NRC staff concludes that Leak BeforeBreak remains valid for SL- 1 under EPU conditions.The Unit 1 UFSAR was updated to incorporate the effects of the staff's approval. Section 3.1.4was revised to read:Due to the application of leak before break methodology to the RCS hot and cold leg piping, thedynamic effects of a loss of coolant accident do not have to be considered. A technicalevaluation was performed to demonstrate that the probability or likelihood of large pipe breaksoccurring in the primary coolant loops is sufficiently low that they need not be a design basis.UFSAR Section 3.6.2 was revised to include the following acceptance criteria:It should be noted that circumferential (guillotine) and longitudinal (slot) breaks in RCS hot andcold leg piping are no longer considered a design basis for GDC 4 (NRC acceptance letter forleak-before-break). The primary loop piping is not susceptible to failure from the effects ofcorrosion, water hammer, fatigue, brittle fracture or indirect causes such as missiles or failure ofnearby components. As a result, the mechanical/structural loadings associated with the dynamiceffects of a large hot or cold leg break need not be considered.The proposed permanent removal of the upper two 4-inch reactor coolant pump RCP 1A2 whip(cable) restraints meets the acceptance criteria found in Generic Letter 87-11. Also asdocumented in NRC letter dated March 5, 1993, the NRC staff has concluded that since the St.Lucie Units are bounded by the CEOG analyses and the leakage detection systems are capable ofdetecting the specified leakage rate, the dynamic effects associated with postulated pipe breaks in9 St. Lucie Unit I L-2014-125Docket No. 50-335 Enclosurethe primary coolant system piping can be excluded from the licensing and design bases of the St.Lucie Units. The EPU leak-before-break evaluation is based on evaluation CEN-367-A. Theprimary loop piping normal operating, SSE and pressure loads due to the EPU conditions wereused in the EPU evaluation. The results of the evaluation demonstrated that leak-before-breakrecommended margins for the primary loop piping continue to be satisfied for the EPUconditions. Calculation CN-MRCDA-09-68 provides an analysis of the RCP and surroundingcomponents to demonstrate the RCP HELB cable restraints for pumps lAl, 1A2, 1B1 and 1B2can be permanently removed. In addition, calculation CN-MRCDA-09-06 documents thatsufficient leak-before-break margin on crack stability is maintained on the main coolant loop hotand cold leg pipes under EPU conditions. NRC letter dated July 9, 2012, concludes that LeakBefore Break remains valid for SL-1 under EPU conditions. The permanent removal of theupper RCP 1A2 whip restraints meets the acceptance criteria of BTP 3-1, as contained in SRPSection 3.6.2, in that absent the whip restraints the primary coolant system piping continues tomeet the applicable ASME Code design requirements.There are no Technical Specifications that address the restraints. However, as discussed in theSafety Evaluation by the NRC on Leak-Before-Break (LBB) Technology, the acceptance of LBBis based on a leakage detection system consistent with Regulatory Guide 1.45, "Reactor CoolantPressure Boundary Leakage Detection Systems." Technical Specification Section 3/4.4.6.1addresses the RCS leakage detection system and no changes to this section or any other section isrequired as a result of the removal of the cable restraints.A License Amendment Request is not required. The RCS whip restraints were installed duringinitial construction of St. Lucie Unit I to mitigate the dynamic effects associated with postulatedRCS hot and cold leg piping breaks. In 1993 the dynanmic effects associated with postulated piperuptures in RCS hot and cold leg piping were excluded from the design and licensing bases of St.Lucie Unit 1, as described in UFSAR Section 3.6. In 2012, it was concluded that the leak beforebreak analysis remains valid for EPU conditions. Because the proposed change does not requirea change to the technical specifications and does not meet any of the criteria in 10 CFR50.59(c)(2), the change can be made without obtaining a license amendment pursuant to 10 CFR50.90.10 St. Lucie Unit IDocket No. 50-335L-2014-125EnclosureSECTION 250.59 EVALUATIONSFor the time period of this report, there were no changes to the facility (outside of the plantdesign modifications discussed in Section 1) as described in the Updated Final Safety AnalysisReport (UFSAR) performed by a 10 CFR 50.59 Evaluation.11 St. Lucie Unit IDocket No. 50-335L-2014-125EnclosureSECTION 3CORE RELOAD EVALUATION12 St. Lucie Unit I L-2014-125Docket No. 50-335 EnclosureEC 277290, REVISION 0ST. LUCIE UNIT I CYCLE 25 RELOADSUMMARYThe l0CFR50.59 Applicability/Screening performed for the St. Lucie Unit 1 Cycle 25 CoreReload concluded, based upon the changes provided in the reload EC [i.e., the new fuel batchRegion GG (88 fresh assemblies), implementation of a Zircaloy-4 MONOBLOC comer guidetube design, reduction in AFW flow and increased AFW temperature in accident analyses, SITline MOVs position to be less than 100% open (>90%), SG blowdown flow isolation in 30minutes instead of 20 minutes, and tripping of all four RCPs instead of two at 30 minutes], someitems could not screen out and had to be evaluated further in this document. The items to becovered in this 10CFR50.59 evaluation are the analytical parameter value changes to the AFWpressure/flow conditions, increased AFW temperature, and SG blowdown isolation timing in theaccident analyses, which constitute a change that adversely affects the UFSAR describedfunctions of the systems relied upon to mitigate the consequences of the loss of feedwater(LOFW) and feedwater (FW) line break events.The actual AFW operating point has been observed to be at pressures up to 1030 psia, whereasthe accident analyses had only considered conditions up to 1000 psia. Also, pump heat added tothe fluid had not been considered in the analyses. As a result, the input parameters for the AFWpumps was revised to add an operating point at 1030 psia, with a minimum degraded AFW flowrate of 276 gpm, and a maximum uncertainty adjusted AFW fluid temperature of ll 1.5°F(previous value being used was 104'F). At the same time, the analyses were run with the timeassumed for the operator to isolate the SG blowdown flow to be 30 minutes instead of thepreviously assumed timing in the Chapter 10 LOFW analysis of 20 minutes. These items wereconsidered adverse, as these changes could adversely affect the AFW system capability toremove heat from the primary system via the steam generators to cool down the RCS duringpost-accident conditions, and because of the delay in SG blowdown isolation which could affectSG inventory and challenge the heat removal to maintain RCS subcooling. These parametersrequired the re-analyses to be performed for three UFSAR events: the loss of normal feedwater(UFSAR Section 15.2.8), the loss of normal feedwater concurrent with Auxiliary Feedwater pipebreak (UFSAR Chapter 10), and the feedwater line break (UFSAR Section 10.5.3). The newresults of these three analyses provided in Reference I and discussed in the reload EC show thatthe analyses meet the same acceptance criteria as before and the consequences of these analysesremain unchanged from those presented in the UFSAR. These analyses are being incorporatedinto the UFSAR with a change package provided in Attachment 2 of the EC.The discussions within this EC, along with the 10 CFR 50.59 Screening and Evaluation justifythat the design and operation of the Cycle 25 reload core will meet the 10 CFR 50.59 (c)(2)criteria. The core reload activities can be implemented with no changes to the St. Lucie Unit 1Technical Specifications. The safety analyses results are within the acceptance limits providedby the USNRC regulatory criteria and within the criteria provided by 10 CFR 50.59. Therefore,prior NRC approval is not required for implementation of this EC-DCP for operation in allModes.13