ML12144A135
| ML12144A135 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 05/22/2012 |
| From: | Jacobs D Entergy Nuclear South, Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC ME7342, W3F1-2012-0028 | |
| Download: ML12144A135 (17) | |
Text
SEntergyEntergy Nuclear SouthEntergy Operations, Inc.17265 River RoadKillona, LA 70057-3093Tel 504 739 6660Fax. 504 739 6678Djacob2@entergy.comDonna JacobsVice President, OperationsWaterford 3W3F1-2012-0028May 22, 2012U.S. Nuclear Regulatory CommissionAttn: Document Control DeskWashington, DC 20555-0001
SUBJECT:
References:
Supplement 2 of License Amendment Request to revise TechnicalSpecification 3/4.7.4 Table 3.7-3, "Ultimate Heat Sink Minimum FanRequirements per Train" [TAC No. ME7342]Waterford Steam Electric Station, Unit 3Docket No. 50-382License No. NPF-381. Waterford 3 Letter W3F1-2011-0067, License Amendment Request,Proposed Change to Technical Specification 3/4.7.4 Table 3.7-3, "UltimateHeat Sink Minimum Fan Requirements per Train" (ADAMS Accession No.ML11290A009) dated October 13, 2011.2. Waterford 3 Letter W3F1-2011-0082, Supplement to License AmendmentRequest, Proposed Change to Technical Specification 3/4.7.4 Table 3.7-3,"Ultimate Heat Sink Minimum Fan Requirements per Train" (ADAMSAccession No. ML113290070) dated November 25, 2011.3. Waterford 3 Letter W3F1 -2012-0004, Calculations Requested for LicenseAmendment Request, Proposed Change to Technical Specification 3/4.7.4Table 3.7-3, "Ultimate Heat Sink Minimum Fan Requirements per Train"(ADAMS Accession No. ML12023A080) dated January 18, 2012.4. Waterford 3 Letter W3F1 -2012-0019, Response to Request for AdditionalInformation, License Amendment Request to revise Technical Specification3/4.7.4 Table 3.7-3, "Ultimate Heat Sink Minimum Fan Requirements perTrain" (ADAMS Accession No. ML12095A308) dated April 3, 2012
Dear Sir or Madam:
By letter dated October 13, 2011, as supplemented by letters dated November 25, 2011, andJanuary 18, 2012 (References 1, 2, and 3), Entergy Operations, Inc. (Entergy) madeapplication to amend Technical Specification (TS) 3/4.7.4 Table 3.7-3, "Ultimate Heat SinkMinimum Fan Requirements per Train" of the Waterford Steam Electric Station, Unit 3(Waterford 3).AoIM W3F1-2012-0028Page 2In Reference 4, Waterford 3 committed to provide a supplement to its application to amendTS 3/4.7.4 Table 3.7-3, "Ultimate Heat Sink Minimum Fan Requirements per Train" to ensurea conservative revised specification is developed for NRC approval. This letter provides thatsupplement.Waterford 3 TS 3/4.7.4 Table 3.7-3 specifies the minimum DCT and WCT fan requirementsfor given ambient temperature conditions. This request modifies the WCT fan requirementsby requiring that all eight WCT fans be operable for the WCT to be considered operable,regardless of ambient temperature. This change is needed because the current WCT fanrequirement limits for operation with fans out of service were based on an inappropriateanalysis methodology. Waterford 3 has entered this condition into the corrective actionprocess (Condition Report CR-WF3-2012-1395) to identify the inappropriate methodology.The revised analysis demonstrates that the Ultimate Heat Sink (UHS) remains capable oftransferring the design basis heat load while maintaining the required cooling water supplytemperature.For the current configuration with all 8 WCT fans operable, design basis calculationsvalidated by thermal performance testing completed by System Engineering on a 5 yearfrequency demonstrate that the WCT is capable of performing its design basis function.Waterford 3 has implemented administrative controls, in accordance with NRC Administrativeletter 98-10 to address potential non-conservatisms in the TS limits for WCT fanrequirements.A mark-up of the tentative changes to TS Bases 3/4.7.3 is included for information.The proposed change has been evaluated in accordance with 10 CFR 50.91(a)(1) usingcriteria in 10 CFR 50.92(c), and it has been determined that the change involves nosignificant hazards considerations.The proposed change involves no new commitments. Please contact William Steelman,Licensing Manager, at 504-739-6685 if there are any comments regarding this response.I declare under penalty of perjury that the foregoing is true and correct. Executed onMay 22, 2012.Sincerely,Attachments:1. Analysis of Proposed Technical Specification Change2. Proposed Technical Specification Changes (mark-up)3. Proposed Technical Specification Changes (clean copy)4. Tentative Technical Specification Bases Changes (mark-up)
W3F1 -2012-0028Page 3cc: Mr. Elmo E. Collins, Jr.Regional AdministratorU. S. Nuclear Regulatory CommissionRegion IV1600 E. Lamar Blvd.Arlington, TX 76011-4125NRC Senior Resident InspectorWaterford Steam Electric Station Unit 3P.O. Box 822Killona, LA 70057-0751U. S. Nuclear Regulatory CommissionAttn: Mr. N. KalyanamMail Stop O-07D1Washington, DC 20555-0001Louisiana Department of EnvironmentalQualityOffice of Environmental ComplianceEmergency and Radiological Services DivisionP. O. Box 4312Baton Rouge, LA 70821-4312RidsRgn4MailCenter@nrc.govMarlone.Davis@nrc.govDean.Overland@nrc.govKaly.Kalyanam@nrc.govJi.Wiley@LA.gov Attachment I toW3F1-2012-0028Analysis of Proposed Technical Specification Change toW3F1`-2012-0028Page 1 of 61.0 DESCRIPTIONBy letter dated October 13, 2011, as supplemented by letters dated November 25, 2011, andJanuary 18, 2012 (References 7.1, 7.2, and 7.3), Entergy Operations, Inc. (Entergy) madeapplication to amend Technical Specification (TS) 3/4.7.4 Table 3.7-3, "Ultimate Heat SinkMinimum Fan Requirements per Train" of the Waterford Steam Electric Station, Unit 3(Waterford 3).In Reference 7.4, Waterford 3 committed to provide a supplement to its application to amendTS 3/4.7.4 Table 3.7-3, "Ultimate Heat Sink Minimum Fan Requirements per Train" to ensurea conservative revised specification is developed for NRC approval. This letter provides thatsupplement.Waterford 3 TS 3/4.7.4 Table 3.7-3 specifies the minimum DCT and WCT fan requirementsfor given ambient temperature conditions. This request modifies the WCT fan requirementsby requiring that all eight WCT fans be operable for the WCT to be considered operable,regardless of ambient temperature. This change is needed because the current WCT fanrequirement limits were based on an inappropriate analysis methodology. Waterford 3 hasentered this condition into the corrective action process (Condition Report CR-WF3-2012-1395) to identify the inappropriate methodology.The revised analysis demonstrates that the Ultimate Heat Sink (UHS) remains capable oftransferring the design basis heat load while maintaining the required cooling water supplytemperature.For the current configuration with all 8 WCT fans operable, design basis calculations,validated by thermal performance testing completed by System Engineering on a periodicbasis, demonstrate that the WCT is capable of performing its design basis function.Waterford 3 has implemented administrative controls, in accordance with NRC Administrativeletter 98-10 to address potential non-conservatisms in the TS limits for WCT fanrequirements.2.0 PROPOSED CHANGEThe proposed modification of TS Table 3.7-3 will be to specify that all WCT fans are requiredto be operable for the WCT to be considered operable. The previous submittal W3F1-2011-0067 (Reference 7.1) continues to request the dry bulb temperature limits for the DCT to bereduced. These changes are intended to correct non-conservatisms in the TS relative to theWCT and account for increased heat load due to the Replacement Steam Generators. Thespecific TS changes are listed below.For the DCT, lower the ambient dry bulb temperature limit for 14 fans from 980F to970F.For the WCT, require all eight fans regardless of ambient temperature. toW3F1-2012-0028Page 2 of 63.0 ..BACKGROUNDThe function of the Ultimate Heat Sink (UHS) is to dissipate the heat removed from thereactor and its auxiliaries during normal operation, during refueling, or after a design basisaccident. The UHS consists of a DCT, a WCT, and the water stored in the WCT basins. Two100% capacity trains employ one DCT and one WCT each.The DCT removes heat from the Component Cooling Water (CCW) system, which is aclosed cooling system that serves reactor auxiliaries. The Auxiliary Component CoolingWater (ACCW) system is a separate system that provides cooling water to the CCW heatexchanger and utilizes the WCT for heat dissipation to the atmosphere. The CCW andACCW systems are described in the Updated Final Safety Analysis Report (UFSAR) Section9.2.2.Each DCT is sized to dissipate approximately 60% of heat removed by the CCW Systemafter a Loss of Coolant Accident (LOCA). The heat removal capacity of the DCT variessignificantly depending on the CCW temperature, atmospheric dry bulb temperature, and theheat removal by the ACCW system. Each DCT consists of five separate cells; each cellcontains two vertical cooling coils. Cooling for each cell is provided by three fans. InEmergency operation, the DCT fans are started and shut-off automatically to maintain theCCW supply temperature at a predetermined setpoint. When the water outlet temperature ofthe CCW Heat Exchanger exceeds another predetermined setpoint, the associated ACCWpump automatically starts, which initiates heat removal via the WCTs.The WCT is designed to operate whenever the heat rejection capacity of the DCT isexceeded or ambient conditions degrade the ability of the DCT to reject its heat load. TheWCT ban also be used to maintain the CCW system temperature below the range,maintained by the DCT during normal operation.Each WCT is sized to dissipate approximately 40% of the heat removed by the CCW systemafter a LOCA to the atmosphere. The capacity of the WCT varies significantly, depending onthe CCW temperature to be maintained and the atmosphere wet bulb temperature. EachWCT consists of two cells separated by a concrete barrier, which prevents air recirculationbetween the fans of each cell. The WCT fans are started automatically whenever the watertemperature in the WCT basin exceeds a predetermined setpoint.The previous method for determining the WCT fan requirements for a given ambienttemperature used a Cooling Tower Institute (CTI) equation that is not intended for thatpurpose. The equation correlates cooling tower performance to the cube root of the ratio ofactual fan horsepower to design fan horsepower. A cooling tower industry expert confirmedthat the equation is intended to be used for comparing design performance to testperformance where small changes in fan horsepower were measured. It was not intended topredict tower performance where total fan horsepower is reduced by large amounts.Therefore, the results of the analysis and the associated TS limits are potentially non-conservative.In addition, after the Replacement Steam Generators are installed, the UHS will have ahigher heat duty, which impacts the ambient temperature limits on TS Table 3.7-3. toW3F1-2012-0028Page 3 of 64.0 TECHNICAL ANALYSISThe current TS Table 3.7-3 for WCT fan requirements for a given ambient temperature is notconservative because it is based on inappropriate analysis methodology.TS Table 3.7-3, which specifies the number of WCT fans operable for a given wet bulbtemperature, will be revised. All eight fans will be required for the WCT to be consideredoperable regardless of ambient temperature.This change is necessary because the design basis analysis for determining the ambienttemperature limits with WCT fans out of service used an inappropriate methodology.In addition to the changes to address the non-conservatisms in TS Table 3.7-3, the dry bulbtemperature limit for one DCT fan out-of-service will also be lowered to account for theincreased heat load as a result of the Replacement Steam Generators. For the DCT, thetemperature was lowered so that all 15 fans are required to be operable with a dry bulbtemperature greater than or equal to 970F. The ambient temperature limit for 3 DCT fans out-of-service will remain unchanged at < 91OF.The revised temperature is based on calculations ECM95-008, ECM95-009, and ECI91-029,and additional margin. With the above changes, the UHS will continue to meet its designfunction to dissipate the heat removed from the reactor and its auxiliaries during normaloperation, during refueling, or after a design basis accident. The TS Bases 3/4.7.4 indicatesthat the calculated temperature values associated with the fan requirements have beenrounded in the conservative direction and lowered at least one full degree.5.0 REGULATORY ANALYSIS5.1 Applicable Regulatory Requirements/CriteriaEntergy Operations, Inc. (Entergy) proposes to modify TS Table 3.7-3, "Ultimate Heat SinkMinimum Fan Requirements per Train," by specifying that all eight WCT fans are requiredregardless of ambient temperature and lowering the dry bulb temperature limit for one DCTfan out-of-service. This change will correct a non-conservative TS and account for increasedheat load resulting from the Replacement Steam Generators.This change to TS Table 3.7-3 does not involve any physical changes to the plant or to theCCW/ACCW system design that would affect the intent of the General Design Criteria,national standards, or engineering principles. Consistency.with the defense-in-depthphilosophy is maintained in that the independence of fission product barriers has not beendegraded by the TS change. Sufficient safety margins are maintained in that the proposedchange is not in conflict with approved Codes and standards relevant to the CCW/ACCWsystem, such as GDC 2, GDC 44, ANSI N18.2-1973, ANSI N18.2a-1975, Regulatory Guide1.27-1976, Regulatory Guide 1.29-1973, and Regulatory Guide 1.53-1973. The proposedchanges will lower the ambient temperature limit for one DCT fan out-of-service in Table 3.7-3. The revised temperature is based on calculations ECM95-008, ECM95-009, and ECI91-029, and additional margin. With the above changes, the UHS will continue to meet itsdesign function to dissipate the heat removed from the reactor and its auxiliaries duringnormal operation, during refueling, or after a design basis accident. The revised analysis toW3F1-2012-0028Page 4 of 6demonstrates that the UHS remains capable of transferring the design basis heat load whilemaintaining the required cooling water supply temperature. The TS Bases 3/4.7.4 indicatesthat the calculated temperature values associated with the fan requirements have beenrounded in the conservative direction and lowered at least one full degree.In conclusion, Entergy has determined that the proposed change does not require anyexception or relief from regulatory requirements and does not adversely affect systems,structures, and components described in the Waterford 3 FSAR. Based on FSAR 9.2.5, thefunction of the UHS is to dissipate the heat removed from the reactor and its auxiliariesduring normal operation, during refueling or after a design basis accident. The proposedchanges to place more restrictive ambient temperature limits for DCT fans and increaseWCT fan requirements do not adversely affect the design function, method of controlling adesign function, or any method of evaluation that demonstrates intended design function ofthe UHS as described in the FSAR.5.2 No Significant Hazards ConsiderationsEntergy Operations, Inc. has evaluated whether or not a significant hazards considerations isinvolved with the proposed amendment by focusing on the three standards set forth in10CFR50.92, "Issuance of amendment," as discussed below:1. Does the proposed change involve a significant increase in the probability orconsequences of an accident previously evaluated?Response: No.The proposed change modifies Technical Specification (TS) 3/4.7.4 Table 3.7-3 to beconsistent with the revised design basis calculation for Dry Cooling Tower (DCT) fanrequirements and to compensate for an inappropriate methodology in the calculationfor Wet Cooling Tower (WCT) fan requirements. This change is necessary topreserve the assumptions and limits of the revised Ultimate Heat Sink (UHS) designbasis calculation. The calculation determines the number of cooling tower fansrequired for a given ambient temperature and establishes more restrictive coolingtower fan operating requirements. The proposed change does not directly affect anymaterial condition of the plant that could contribute to an accident or that couldcontribute to the consequences of an accident. The proposed change ensures thatthe mitigating effects of the UHS will be consistent with the design basis analysis.Therefore, the proposed change will not involve a significant increase in theprobability or consequences of any accident previously evaluated.2. Does the proposed change create the possibility of a new or different kind of accidentfrom any accident previously evaluated?Response: No.The proposed change modifies TS 3/4.7.4 Table 3.7-3 to be consistent with therevised design basis calculation for DCT fan requirements and to compensate for aninappropriate methodology in the calculation for WCT fan requirements. The revisedTS lowers the dry bulb temperature limit for one DCT fan out-of-service to account forincreased heat load due to the Replacement Steam Generators. This change also toW3F1-2012-0028Page 5 of 6implements more restrictive WCT minimum fan requirements. The proposed changeto Table 3.7-3 does not alter the operation of the plant or the manner in which theplant is operated such that it creates credible new failure mechanisms, malfunctions,or accident initiators. Therefore, the proposed change will not create the possibility ofa new or different kind of accident from any accident previously evaluated.3. Does the proposed change involve a significant reduction in a margin of safety?Response: No.The proposed change modifies TS 3/4.7.4 Table 3.7-3 to be consistent with therevised design basis calculation for DCT fan requirements and to compensate for aninappropriate methodology in the calculation for WCT fan requirements. Morerestrictive cooling tower fan operability requirements result from lowering the ambienttemperature limit for one DCT fan out-of-service and requiring all eight WCT fans,regardless of ambient temperature. The revised temperatures are based oncalculations ECM95-008, ECM95-009, and ECI91-029, and additional margin. TheTS Bases 3/4.7.4 indicates that the calculated temperature values associated with thefan requirements have been rounded in the conservative direction and lowered atleast one full degree. The proposed change preserves the margin of safety byensuring that the UHS is capable of transferring the required heat load andmaintaining cooling water supply temperature within limits with the minimum numberof operable fans for a given ambient temperature. The proposed change does notexceed or alter a design basis or safety limit. Therefore, the proposed change will notinvolve a significant reduction in a margin of safety.Based on the above, Entergy concludes that the proposed amendment presents nosignificant hazards considerations under the standards set forth in 10 CFR 50.92(c), and,accordingly, a finding of "no significant hazards considerations" is justified.5.3 Environmental ConsiderationsThe proposed amendment does not involve (i) a significant hazards considerations, (ii) asignificant change in the types or significant increase in the amounts of any effluent that maybe released offsite, or (iii) a significant increase in individual or cumulative occupationalradiation exposure. Accordingly, the proposed amendment meets the eligibility criterion forcategorical exclusion set forth in 1 OCR51.22(c)(9). Therefore, pursuant to 1 OCFR51.22(b),no environmental impact statement or environmental assessment need be prepared inconnection with the proposed amendment.6.0 PRECEDENCEThere is no precedence identified. toW3F1-2012-0028Page 6 of 67.0 REFERENCES7.1 Waterford 3 Letter W3F1 -2011-0067, License Amendment Request, ProposedChange to Technical Specification 3/4.7.4 Table 3.7-3, "Ultimate Heat Sink MinimumFan Requirements per Train" (ADAMS Accession No. ML1 1290A009) datedOctober 13, 2011.7.2 Waterford 3 Letter W3F1-2011-0082, Supplement to License Amendment Request,Proposed Change to Technical Specification 3/4.7.4 Table 3.7-3, "Ultimate Heat SinkMinimum Fan Requirements per Train" (ADAMS Accession No. ML1 13290070) datedNovember 25, 2011.7.3. Waterford 3 Letter W3F1-2012-0004, Calculations Requested for LicenseAmendment Request, Proposed Change to Technical Specification 3/4.7.4 Table 3.7-3, "Ultimate Heat Sink Minimum Fan Requirements per Train" (ADAMS AccessionNo. ML12023A080) dated January 18, 2012.7.4, Waterford 3 Letter W3F1-2012-0019, Response to Request for Additional Information,License Amendment Request to revise Technical Specification 3/4.7.4 Table 3.7-3,"Ultimate Heat Sink Minimum Fan Requirements per Train" (ADAMS Accession No.ML12095A308) dated April 3, 20127.5 Technical Specifications (TS).7.6 Updated Final Safety Analysis Report (UFSAR) Revision 305. toW3F1-2012-0028Proposed Technical Specification Changes (mark-up) toW3F1-2012-0028Page 1 of 1[Note that the change reflected for the Dry Cooling Tower is replicated from thepreviously submitted mark-up.]AMBIENTýCONDITIONFanRoquirmmontslII15 14' 12,7L ~ ~ ~ ~ ~ i m~' Kam~~ amiad1 'fL odIE1io of- -w = stall ~ --' be OPEAUWATERFORD -UMT 31141 114WATEFOR. UT 3 I47.14AMENDMENT NO. OS-423.13 toW3F1-2012-0028Proposed Technical Specification Changes (clean copy)Attachment contains 1 page.
TABLE 3.7-3ULTIMATE HEAT SINK MINIMUM FAN REQUIREMENTS PER TRAINDRY COOLING TOWERN DRY BULB > 970F 970F > DRY BULB > 91°F15 14*AMBIENT Fan Requirements(')DRY BULB < 91°F12*WET COOLING TOWERFan Requirements -8(1) With any of the above required DCT fans inoperable, comply with ACTION d.* With a tornado watch in effect, all 9 DCT fans under the missile protected portion of the DCT shall be OPERABLE.WATERFORD -UNIT 33/4 7-14AMENDMENT NO. 95,123,39 toW3F1-2012-0028Tentative TS Bases Changes (Mark-up) toW3F1-2012-0028Page 1 of 2PLANT SYSTEMSBASES314.7.4 ULTIMATE HEAT SINKThe limitations on the ultimate heat sink level, temperature, and number of fans ensurethat sufficient cooling capacity is available to either (1) provide normal cooldown of the facility, or(2) to mitigate the effects of accident conditions within acceptable limits.The UHS consists of two dry cooling towers (DCTs), two wet cooling towers (WCTs), andwater stored in WCT basins. Each of two 100 percent capacity loops employs a dry and wetcooling tower-Each DCT consists of five separate cells. Cooling air for each cell is provided by 3 fans,for a total of 15 per DCT. The cooling coils on three cels of each DCT (i.e. 60%) are protectedfrom tornado missiles by grating located above the cola and capable of withstanding tornadomissile impact. With a Tornado Watch in effect and the number of fans OPERABLE within themissile protected area of a OCT less than that required by Table 3.7-3, ACTION c requires therestoration of inoperable fans within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or plant shutdown as specified. This ACTION isbased on FSAR analysis (subsection 9.2.5.3.3) that assumes the worst case single failure as, 1emergency diesel generator coincident with a loss of offtite power. This failure occurssubsequent to a tornado strike and 60% cooling capacity of a DCT is assumed available.elk Wl&Each WCT has a basin which is capable of storing sufficient water to bring the plant to safeshutdown under all design basis accident conditions. Item a of LCO 3/4.7.4 requires a minimumwater level in each WCT basin of 97% (-9.86 ft MSL). When the WCT basin water level ismaintained at -9.86 ft MSL, each basin has a minimum capacity of 174,000 gallons. This minimumWCT basin capacity contains enough volume to account for water evaporation and drift lossesexpected during a LOCA. Additional volume is needed from the second WCT basin to handle thenon-essential load of fuel pool cooling during the LOCA. (The WCTs can be manuallyinterconnected through a Seismic Category I line.) The WCT basin is also credited as a source ofEmergency Feedwater (EFW). The WCT minimum capacity bounds the amount of EFW requiredfrom the WCT basin for all design basis accidents. Each WCT consists of two cells, each cell isserviced by 4 induced draft fans, for a total of 8 per WCT. There is a concrete partitionbetwaenth~at prevents air recirculation b~etween thfans of each cell Table 3.7-3 spec'jJa~51 or decreased fan OPERABILITY requirements based onoutside air temperatur<'& J V W The table provides the cooling tower fan OPERABILITYrequirements that may vary wit outside ambient conditions. Fan OPERABILITY aresacified for eas controlling parameter (i.e., dry bulb temperatures for DCT fan.10-ý=lThe calculated temperature values (EC-M95-O09) associatedAMENDMENT NO. 95, "4,2, ,-39WATERFORD -UNIT 3 B 3/4 7-4 CHANGE NO. 4-, 38 toW3F1-2012-0028Page 2 of 2PLANT SYSTEMSBASES (Continued)3/4.7.4 ULTIMATE HEAT SINK (Continued) metwkan requirements have been rounded in the conseWdtve direction and loweredat l -n-efiIdegre .alure to-.e.4the OPERABILITYghLients of Table 3.T-uquf u-y- 1 ,,3 applicable action. Because temper atfui47ýubject to change during the day, ACTION d requires periodic temperature readinigto verify compliance with Table 3.7-3 when any cooling tower fan is inoperable.The limitations on minimum water level and maximum temperature are based onproviding a 30-day cooling water supply to essential equipment without exceeding theirdesign basis temperature and is consistent with the recommendations of Regulatory Guide 1.27,"Ultimate Heat Sink for Nuclear Plants,* March 1974.-DRN 06-124A, Ch. 36AMENDMENT NO. 449,CHANGE NO. 1&, 38WATERFORD -UNIT 3B 3/4 7-4 (1)