Application for amends to licenses DPR-67 & NPF-16 ... · c.St. Lucie Unit1 and Unit2 Docket Nos. 50-335 and 50-389 Proposed License Amendments LPSI S stem Risk Informed AOT Extension

CATZaoax 1REGULA' INFORMATION DISTRIBUTI . SYSTEM (RIDS)

ACCESSION NBR:9906090019 DOC.DATE: 99/06/01 NOTARIZED: YESFACXL:5'-335 St. Lucie Plant, Unit 1, Florida Power & Light Co.

,$ 0-.389 St. Lucie Plant, Unit 2, Florida Power 8 Light Co.ASH';NAME AUTHOR AFFILIATION

STA/L,J.A. Florida Power E Light Co.RECIP.NAME RECIPIENT AFFILIATION

Records Management Branch (Document Control Desk)

DOCKET0500033505000389

SUBJECT: Application for amends to licenses DPR-67 & NPF-16,revisingTS 3.5.2 to allow up to 7 days to restore inoperable LPSItrain to operable status.

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Florida Power &Light Company, 6351 S. Ocean Drive, Jensen Beach, FL34S57

June 1, 1999 L-99-07910 CFR 50.90

U. S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555

RE: St. Lucie Unit 1 and Unit 2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension

Pursuant to 10 CFR 50.90, Florida Power 8 Light Company (FPL) requests to amend FacilityOperating Licenses DPR-67 and NPF-16 for St. Lucie Unit 1 and Unit 2, respectively, byincorporating the attached Technical Specifications (TS) revisions. The amendments will reviseTS 3.5.2 to allow up to 7 days to restore an inoperable Low Pressure Safety Injection (LPSI) trainto operable status. The proposed action completion/allowed outage time (AOT) will enhanceoverall plant safety by avoiding potential unscheduled plant shutdowns, and by providingincreased flexibilityfor scheduling and performing maintenance activities. The risk-informed AOTis based on a cooperative study by participating Combustion Engineering Owners Group (GEOG)members. The joint applications report of that study (CE NPSD-995) is applicable to both St.Lucie units and was submitted to the DCD for each St. Lucie docket on June 21, 1995.

FPL has developed improved input data and enhancements to the Probabilistic SafetyAssessment (PSA) model for each St. Lucie unit. The results of these improvements relative tothe LPSI AOT are provided herein and supersede the corresponding plant-specific information inCE NPSD-995. It is requested that the proposed amendments be issued by February 29, 2000.

Attachment 1 is an evaluation of the proposed changes. Attachment 2 is the "Determination of NoSignificant Hazards Consideration." Attachments 3 and 4 contain copies of the appropriatetechnical specifications pages marked up to show the proposed changes. The St. Lucie FacilityReview Group and the FPL Company Nuclear Review Board have reviewed the proposedamendments, and a copy of this submittal is being forwarded to the State Designee for the Stateof Florida in accordance with 10 CFR 50.91 (b) (1).

Please contact us if there are any questions about this submittal.

Very truly yours,

J. A. StallVice PresidentSt. Lucie Plant

JAS/RLDAttachments

990S0900<9 ~ego~PDR ADOCK 05000335p PDR

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Regional Administrator, Region II, USNRCSenior Resident Inspector, USNRC, St. Lucie PlantMr. W.A. Passetti, Florida Department of Health and Rehabilitative Services

an FPL Group company

St. Lucie Unit1 and Unit2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension

L-99-079Page 2

STATE OF FLORIDA )) ss.

COUNTY OF ST. LUCIE )

J. A. Stall being first duly sworn, deposes and says:

That he is Vice President, St. Lucie Plant, for the Nuclear Division of Florida Power & LightCompany, the Licensee herein;

That he has executed the foregoing document; that the statements made in this document aretrue and correct to the best of his knowledge, information and belief, and that he is authorized toexecute the document on behalf of said Licensee.

J. A. Stall

STATE OF FLORIDA

COUNTY OF t. L

Sworn to and subscribed before me

this 14. day of ,~a'8

by J. A. Stall, who is personally known to me.

Si ture of Notary ubl'tate of FloridaLeslle J. Whltwell

MY COMMISSION 4 CCQ6183 EXPIRES

May 12, 200180NOED 1HRU TROY FAN ICSRA!CE, INC.

Name of Notary Public (Print, Type, or Stamp)

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St. Lucie Unit 1 and Unit 2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension

L-99-079 ATTACHMENT1

EVALUATIONOF PROPOSED TS CHANGES

1.0 Introduction

2.0 Background2.1 Low Pressure Safety Injection (LPSI) System2.2 Technical Specification (TS) 3.5.2, ECCS Subsystems —Tavg ~ 325'F2.3 Previous FPL Correspondence Related to the Proposed Amendments

3.0 Proposed TS Changes: Description and Bases/Justification3.1 Description of TS Changes3.2 Basis for Proposed Changes

3.2.1 Deterministic Assessment of LPSI AOT Extension3.2.2 Piobabilistic Safety Assessment of LPSI AOT Extension3.2.3 Summary of Results forTier 1, 2, and 3 Evaluations3.2.4 Configuration Risk Management Program (CRMP)3.2.5 Other Considerations

4.0 Environmental Consideration

5.0 Conclusion

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c.St. Lucie Unit1 and Unit2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension

L-99-079Attachment 1

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EVALUATIONOF PROPOSED TS CHANGES

1.0 Introduction

Florida Power and Light Company (FPL) requests that Appendix A of Facility Operating LicenseDPR-67 for St. Lucie Unit 1 (PSL1) and NPF-16 for St. Lucie Unit 2 (PSL2) be revised to extendthe action completion/allowed outage time (AOT) for an inoperable Low Pressure Safety Injection(LPSI) train from 72 hours to 7 days. The AOT extension will enhance overall plant safety byavoiding potential unscheduled plant shutdowns, and by providing increased flexibility forscheduling and performing maintenance activities. The proposed AOT is based on the results ofa cooperative study performed by participating members of the Combustion Engineering OwnersGroup (GEOG) in conjunction with information provided herein. The study included an integratedreview and assessment of plant operations, deterministic design basis factors, and overall plantrisk using probabilistic safety assessment (PSA) techniques.

The NRC has been reviewing and granting improvements to technical specifications (TS) that arebased, at least in part, on probabilistic risk assessment insights since the mid-1980's. In concertwith this initiative, the GEOG submitted several joint application reports that provide justificationsfor TS AOT extensions to the NRC staff for generic review (GEOG Letter 95-344, D.F. Pilmer toNRC Document Control Desk, C-E Owners Group Submiffal ofJoint Appircaffon Reports, July 10,1995). The justifications for these extensions are based on a balance of probabilistic andtraditional engineering considerations, and risk assessments for the participating CombustionEngineering (CE) plants are contained in the reports. St. Lucie Unit 1 and Unit 2 were participatingplants in that owner's group task, and the report pertinent to this submittal is CE NPSD-995, JointAppir'cafions Report for Low Pressure Safefy Injection System AOT Extension; ABB-CombustionEngineering Inc., May 1995. A license amendment request based on CE NPSD-995, assupplemented by the GEOG and the licensee, was approved for the designated pilot plant in 1998.

2.1 Low Pressure Safe In'ection LPSI S stem

The Emergency Core Cooling System (ECCS) includes two independent and redundantsubsystems, and each subsystem includes a LPSI train in combination with a High Pressure SafetyInjection (HPSI) train. The plant specific safety analyses for PSL1 and PSL2 demonstrate thateither one of the ECCS subsystems operating in conjunction with the Safety Injection Tanks (SIT)conservatively satisfy the requisite 10 CFR 50.46 ECCS performance acceptance criteria.

Each LPSI train contains a high volume, low head, centrifugal pump designed to supplement theSafety Injection Tank (SIT) inventory in re-flooding the reactor vessel with borated water during theearly stages of a large break Loss of Coolant Accident (LOCA). The LPSI system is actuated byan automatic or manually initiated Safety Injection Actuation Signal (SIAS) which starts theassociated pump and causes the LPSI flow control valves to open. The LPSI pumps transferborated water from the Refueling Water Tank (RWT), through the LPSI header(s), and into thesafety injection penetrations to the Reactor Coolant System (RCS) cold legs. During therecirculation phase of the LOCA scenario, the LPSI pumps are stopped by an automatic ormanually initiated Recirculation Actuation Signal (RAS) and long term core cooling is supplied by

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the HPSI pumps taking suction from the containment sump. The LPSI systems for both St. Lucieunits are functionally the same, but contain differences in the piping arrangement, e.g., PSL1 has acommon LPSI header which branches out to each of the four high pressure cold leg penetrationswhereas PSL2 has two independent LPSI headers, each branching out to two of the high pressurecold leg penetrations.

The primary role of LPSI trains during power operation is to be available for use upon demand forLOCA mitigation. The LPSI system also defines the end-state for a design basis steam generatortube rupture (SGTR) and other non-LOCA design basis events, i.e., the LPSI system would beused for RCS heat removal as part of the shutdown cooling (SDC) system after the initial transientand radioactive releases have been controlled. In addition to being available for accidentmitigation, the most common use of the LPSI systems is for decay heat removal during normalshutdown cooling operations in MODES 4, 5, and 6, and at least one LPSI pump and subtrain arerequired for RCS heat removal in all of these modes. In the shutdown-cooling configuration, theLPSI pumps circulate reactor coolant from the RCS hot legs, through Shutdown Cooling HeatExchangers (SDHX), and into the RCS cold leg penetrations.

Detailed descriptions of the LPSI systems are contained in Section 6.3 of the Updated Final SafetyAnalysis Report (UFSAR) for each St. Lucie unit. Shutdown cooling operations are described inUFSAR Section 9.3.5 (PSL1) and 5.4.7 (PSL2).

2.2 Technical S ecification S 3.5.2 ECCS Subs stems —Tav ~ 325'F

TS 3.5.2 requires two independent ECCS subsystems to be operable in Modes 1 and 2, and inMode 3 when RCS pressure is z 1750 psia. In the event one of the ECCS subsystems becomesinoperable, the Limiting Condition for Operation (LCO) requires the inoperable subsystem to berestored to operable status within 72 hours or the plant must transition to Mode 4 (Hot Shutdown)within the next 12 hours. If both ECCS subsystems become inoperable, action must be initiated incompliance with TS 3.0.3, which would ultimately lead to the cold shutdown condition. Theprescribed 72 hour AOT is based on an NRC study, circa 1975, "using a reliability evaluation [ofECCS components] and is a reasonable amount of time to effect many repairs." (Ref: Page 8 3.5-15 of NUREG-1432, Standard Technical Specifications for Combustion Engineering Plants,Volume 3, Rev. 1; April, 1995).

TS 3.5.2 requires the operability of two separate and independent ECCS subsystems to ensurethat sufficient emergency core cooling capability will be available in the event of a LOCA assumingthe loss of one subsystem through any single failure consideration. Either subsystem operating inconjunction with the safety injection tanks is capable of supplying sufficient core cooling to limit thepeak cladding temperatures within the acceptance criteria for all postulated break sizes rangingfrom the double-ended break of the largest RCS hot Ieg pipe downward. In addition, each ECCSsubsystem provides long-term core cooling capability in the recirculation mode during the accidentrecovery period. In Mode 3 with RCS pressure < 1750 psia and in Mode 4, one operable ECCSsubsystem is acceptable without single failure consideration based on the stable reactivitycondition of the reactor and the limited core cooling requirements.

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2.3 Previous FPL Corres ondence Related to the Pro osed Amendments

1. FPL previously requested an AOT extension for LCO 3.5.2 in letter L-95-133:D.A.Sager (FPL) to NRC (DCD), Docket Nos. 50-335 and 50-389, Proposed LicenseAmendments, LPSI System AOT Extension; June 22, 1995. CE NPSD-995, JointApplications Report for Low Pressure Safety Injection System AOT Extension: ABBCombustion Engineering, Inc; May 1995, was submitted as an enclosure to the FPL letter.

2. FPL letter L-98-290: J.A. Stall (FPL) to NRC (DCD), Docket Nos. 50-335 and 50-389,Withdrawal ofProposed License Amendments for LPSI and EDG Risk Informed TechnicalSpecifications; December 15, 1998 was issued, in part, to withdraw FPL's previousrequest to extend the TS 3.5.2 AOT for an inoperable LPSI train. This letter resulted fromseveral changes that had occurred subsequent to the original submittal: (a) formalguidelines that were being developed during and after the time of FPL's submittal wereissued, e.g., USNRC Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, August 1998; (b) improved input datawas developed and enhancements were made to the St. Lucie PSA models; and (c)improvements to the St. Lucie plant configuration risk management process were beingdeveloped.

3.0 Pro osed TS Chan es: Descri tion and Basis

3.1 Descri tion of TS Chan es

The following proposed changes apply to both St. Lucie units. Marked-up copies of the affectedTS pages are contained in Attachment 3 (PSL1) and Attachment 4 (PSL2).

1. TS 3.5.2 ACTION a. will be revised to include a 7 day risk-informed AOT as follows:

a.1. With one ECCS subsystem inoperable only because its associatedLPSI train is inoperable, restore the inoperable subsystem to OPERABLEstatus within 7 days or be in at least HOT STANDBY within the next 6hours and in HOT SHUTDOWN within the following 6 hours.

a.2. With one ECCS subsystem inoperable for reasons other thancondition a.1., restore the inoperable subsystem to OPERABLE statuswithin 72 hours or be in at least HOT STANDBY within the next 6 hoursand in HOT SHUTDOWN within the following 6 hours.

*h i h 4, ill bthe surveillance test specified for containment sump recirculation.

3. Bases Section 3/4.5.2 and 3/4.5.3, ECCS Subsystems, will be revised by adding thefollowing paragraph:

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+St. Lucie Unit1 and Unit 2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension


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"TS 3.5.2, ACTION a.1. provides an allowed outage/action completion time (AOT) of up to7 days from initial discovery of failure to meet the LCO provided the affected ECCSsubsystem is inoperable only because its associated LPSI train is inoperable. This 7 dayAOT is based on the findings of a deterministic and probabilistic safety analysis and isreferred to as a "risk-informed" AOT extension. Entry into this ACTION requires that a riskassessment be performed in accordance with the Configuration Risk ManagementProgram (CRMP), which is described in the Administrative Procedure (ADM-17.08) thatimplements the Maintenance Rule pursuant to 10 CFR 50.65."

3.2 BasisforPro osedChan es

The current St. Lucie Unit 1 and Unit 2 Technical Specifications address the LPSI system as aportion of the ECCS, and TS 3.5.2 requires two independent ECCS subsystems to be operable inModes 1, 2, and 3 when RCS pressure is 2 1750 psia. With one ECCS subsystem inoperable, thatsubsystem must be returned to operable status within 72 hours or a plant shutdown to Mode 4 isrequired. If both ECCS subsystems become inoperable, action must be initiated in compliancewith TS 3.0.3, which would ultimately lead to the cold shutdown condition. The proposed changeapplies to the case where one ECCS subsystem becomes inoperable, and will allow up to 7 daysto restore that subsystem to operable status, provided the subsystem is inoperable only because aLPSI train is inoperable.

In the upper operating modes, LPSI trains must be available in the event that LOCA mitigationbecomes necessaiy. The estimated frequency of a large LOCA is on the order of E-05 per year.The LPSI system would also be used for RCS heat removal in the event of a SGTR or other non-LOCA design basis events, which have estimated frequencies on the order of E-03 per year andlower. In contrast, at least one LPSI train is required to be operable for RCS heat removal duringnormal shutdown operations in Modes 4, 5, and 6, and is almost always in operation when in thesemodes. Therefore, in the broad view, performing preventive and corrective maintenance on LPSItrains when at power can enhance overall plant safety by increasing the availability and reliability ofthe LPSI system for normal shutdown-cooling operations, i.e., when it is most often needed.

In some cases, corrective maintenance and subsequent testing of a LPSI pump and/or associatedvalves may require a LPSI train to be out of service for more than several days. In such cases,repair within the existing AOT could not be assured and may result in an unscheduled plantshutdown or a request for temporary relief to allow continued plant operation. Based on a reviewof the maintenance requirements of LPSI systems for CE pressurized water reactors, the GEOGstudy described in CE NPSD-995 concluded that a 7-day AOT would provide sufficient margin toeffect most anticipated preventive and corrective maintenance activities and LPSI systemsurveillance tests at power.

3.2.1 Deterministic Assessment of LPSI AOT Extension

10 CFR 50.46 defines deterministic acceptance criteria that are used to judge the acceptability of agiven ECCS design relative to reactor core cooling performance during postulated LOCAs. TheECCS cooling performance for each St. Lucie unit is calculated using acceptable evaluation



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models that are designed pursuant to 10 CFR 50, Appendix K, and satisfies all of the 10 CFR50.46 acceptance criteria. The required and acceptable features of Appendix K evaluation modelsensure that thermohydraulic and hydrodynamic phenomena are conservatively represented in thecalculations of peak cladding temperature (PCT), and the methodology provides assurance thatthe minimum equipment requirements for adequate response to design basis LOCAs areconservative. The PSL1 and PSL2 safety analyses demonstrate that a single train of ECCSequipment operating in conjunction with safety injection tanks provides an adequate andconservative response to such events initiated from full power operation.

As discussed in section 6.2.1 of CE NPSD-995, recent best-estimate analyses for a typicalpressurized water reactor (PWR) suggest that the Appendix K methodology may result inoverstating the minimum equipment requirements for adequate LOCA response. In the examplegiven for large break LOCAs, incipient core melt could be averted by operating combinations ofECCS subsystems other than those currently defined in the ECCS operability requirements, e.g.,operation of a single LPSI pump or the operation of one HPSI pump and a single SIT could provideadequate response to a design basis large LOCA scenario. For each St. Lucie unit, major ECCScomponents include four passively actuated SITs, two HPSI pumps, and two LPSI pumps, and theproposed AOT extension from 72 hours to 7 days will be permitted in a condition where only oneLPSI train is inoperable. If an ECCS subsystem becomes inoperable for any other reason, theexisting 72 hour AOT must be applied. If both ECCS subsystems are inoperable, power operationis not permitted and the plant must ultimately transition to cold shutdown.

For the design basis SGTR and other non-LOCA events where safety injection may be required forRCS inventory control, the HPSI system functions to keep the reactor core covered. The LPSIsystem is only required as part of the SDC system which is used for RCS and core heat removalafter the initial transient and radioactive releases have been controlled. Loss of both LPSI trains isbeyond design basis accident assumptions and the proposed AOT extension does not change thedesign basis for these events. However, in the unlikely event that one I PSI train is out of serviceand the second LPSI train fails, the defense-in-depth principle ensures that operators can continueto control and satisfy the RCS and Core Heat Removal safety function by steaming one or bothsteam generators, as applicable to the specific event, in Mode 3 or 4.

Table 6.2.1-1 of CE NPSD-995 provides a comparison of secondary side heat removal capabilitiesfor GEOG plants, and includes the approximate condensate storage depletion time (without refill).The minimum contained volume of condensate required by the PSL1 and PSL2 TS is 116,000gallons and 307,000 gallons, respectively. However, the steam generator heat sink can bemaintained indefinitely provided make-up condensate remains available to the CondensateStorage Tank (CST). Plant procedures provide instructions for replenishing condensate inventorystorage, and also include instructions for supplying the PSL1 Auxiliary Feedwater Pumps from thePSL2-CST in the event that the smaller PSL1-CST becomes unavailable. Extending the LPSIAOTwould not impact this defense-in-depth capability.

The methodology, assumptions, and results of calculations performed to conservatively assess theradiological consequences of design basis accidents are described in the UFSAR for each St.Lucie unit, and equipment AOTs are not considered in the analyzed accident scenarios. It is

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generally considered that the potential for accident initiation within the brief time intervalsconditionally allowed by the TS for return of inoperable safety-related equipment to operable statusis sufficiently small to justify continued power operations during those intervals. However, theimpact of an AOT interval on the probability and estimated frequency of large radiological releasescan be quantified in a probabilistic framework by using PSA techniques to evaluate the riskassociated with continued plant operations during periods of equipment inoperability. Part 6.2.2 ofthe joint applications report, CE NPSD-995, provides a discussion of the radiological releaseconsiderations included in the GEOG study. The report concludes that potential releases wouldremain within 10 CFR 100 limits in the unlikely event that a design basis accident occurred in thepresence of a compromised ECCS, i.e., no LPSI.

~Summa: Based on recent best estimate analyses for a typical PWR, the design basis LOCArequirement for one LPSI train, one HPSI train, and all SITs to avert a core melt condition isconsidered conservative in that design basis ECCS acceptance criteria could be met if a LOCAoccurred at a time when one LPSI train is out of service. The LPSI system is not required for anon-LOCA event until such time as the event has been brought under control and the plant is at thelow temperature and pressure conditions where SDC operations can be initiated. Moreover,having one LPSI system out of service at the time of event initiation would not impact defense-in-depth capabilities for the RCS and Core Heat Removal safety function at either St. Lucie unit. Inaddition to the accident considerations, the fact that the LPSI system is required for decay heatremoval every time the plant is placed in cold shutdown indicates that it would be prudent toperform maintenance on the LPSI system during power operations rather than during shutdownwhen the demand for the system is at its highest. Therefore, extending the AOT for one inoperableLPSI train from 72 hours to 7 days should continue to ensure defense-in-depth is maintained andsufficient safety margin exists to meet the design basis analyses for the PSL1 and PSL2 ECCS.

3.2.2 Probabilistic Safe Assessment of LPSI AOT Extension

In addition to evaluating the impact of the AOT extension on deterministic factors associated withthe plant design bases, a probabilistic safety assessment of risks involved with applicable plantoperations was also performed by FPL. The assessment generally conforms to the three-tieredapproach to an evaluation of the risk impact from an AOT extension that is identified in RegulatoryPosition C.2.3 of USNRC Regulatory Guide 1.177, An Approach for Planf-Specific, Risk-InfolmedDecisionmaking: Technical Specificafions, August 1998, i.e., Tier 1: PRA Capability and Insights,Tier 2: Avoidance of Risk-Significant Plant Configurations, and Tier 3: Risk-Informed ConfigurationRisk Management. A summary of the results of this approach is provided in Part 3.2.3 of thisattachment.

The considerations, assumptions, methodologies, and detailed results of the initial risk assessmentare reported in CE NPSD-995, Joint Applicafions Report forLow Passu>8 Safety Injection SystemAOTExfension, Final Report GEOG Task 836, prepared for the CE Owners Group, May 1995, assupplemented by the associated RAI response dated May 31, 1996 (GEOG Letter 96-254, D.F.Pilmer to C.l. Grimes, Chief, Technical Specifications Branch, NRR, Project No. 692; June 14,1996). CE NPSD-995 also contains other generic information relevant to the proposed AOTextension that is applicable to both St. Lucie units. The joint applications report, as supplemented,

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in conjunction with the improved data and PSA model enhancements that have been incorporatedsubsequent to 1995 as described in the following paragraphs, forms the risk-informedjustification/basis for the proposed license amendments.

The St. Lucie contribution to the 1995 preparation of CE NPSD-995 was generated using the IPEmodels developed in response to Generic Letter (GL) 88-20, Individual Plant Examinafion forSevere Accident Vulnerabilifies, and associated supplements. Subsequently in 1997, the NRCcompleted its review of the GL 88-20 submittals and in a letter to FPL dated July 21, 1997,Subject: Staff Evaluation Report of St. Lucie, Units 1 and 2, Individual Plant Examination (IPE)Submittal —TAC Nos. M74473 AND M74474, the NRC staff stated, "The NRC staff concludedthat the FPL IPE process is capable of identifying the most likely severe accidents and severeaccident vulnerabilities for St. Lucie, Units 1 and 2, and, therefore, meets the intent of GL 88-20."

Since then, FPL has updated both the models and the reliability/unavailability databases for St.Lucie Units 1 and 2. The updated models and databases were then used to re-calculate the risknumbers for the units. The most significant change included with each model update is thecreation of a "one-top" model which is constructed from the original model's individual top eventsfor various initiators, e.g., small LOCA, large LOCA, SGTR, reactor trips, etc. The one-top modelallows rapid quantification, and each case for this re-evaluation of LPSI was individuallyquantified. The truncation used for quantification was 2E-10 or lower. This replaces the use ofone master cutset file (per unit) in the original (1995) GEOG evaluation.

The model update process included a review of all plant design changes that were implementedsince creation of the original models. Due to the maturity of the St. Lucie units, only one plantdesign change was implemented (PSL2) that resulted in a notable impact on the analysis results,and is discussed in the following summary of significant changes. For the reliability/unavailabilitydatabase update, FPL was able to use the last three years of data gathered pursuant to theMaintenance Rule (10 CFR 50.65) which provided concise, high quality unavailability andreliability data for the risk significant systems. Outside peer review was not performed for theupdate because creating a one-top model essentially involved combining the existing tops for thevarious scenarios, and other model changes that were implemented are not extensive.

A summary of significant model changes and the results of revised risk calculations relevant to theLPSI AOT extension follows:

Test & Maintenance (T&M) events for selected equipment were added to better supportMaintenance Rule implementation and related risk evaluations. Minor improvements were madein the modeling of instrument air systems and in the handling of common cause events.

New initiating event (IE) frequencies were calculated for all LOCAs. This was done in accordancewith GEOG Probabilistic Safety Assessment Working Group (PSAWG) Technical Position Paper,Evaluation of the Initiating Event Frequency for the Loss of Coolant Accident, GEOG Task 941,January 1997. Although the IE frequency for two LOCA sizes (large and small) decreased, thenet impact was an increase in the total LOCA IE frequency of nearly 48%, i.e., from 2.09E-3 to3.09E-3 per year.

The process of adding recoveries is now automated using a recovery "Rule File". The rule fileutilizes a manual recovery action process in that recovery actions are added to each cutset ratherthan being generated from the model; but the process is automated such that all the similar cutset

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scenarios are recovered automatically. This automatic feature ensures uniform and completeinclusion of recovery actions throughout all of the generated cutsets, and yields more realistic andconsistent results.

FPL re-evaluated all offsite power recovery cases for both St. Lucie units. One case was addedto the Unit 1 analysis for recovery of offsite power in 9 hours (approximately 1 hour before the Unit1 CST would deplete without condensate replenishment). The non-recovery probability for onecase was increased for both units due to an incorrect assumption that was used in the originalanalysis. In addition, the related recovery for getting power from the alternate unit was increaseddue to timing considerations. Although 60 minutes total is available (as assumed in the originalevaluation), only 45 minutes remains for power recovery after diagnosis of the event per the plantEmergency Procedures. This factor was combined with hardware related failures to calculate thetotal non-recovery probability of 0.1 for the cross-tie recovery event.

For PSL2, a plant design change was made that requires the SDC suction cross-connect valve tobe locked open. The valve was normally closed during power operations, and this action wastaken in response to concerns raised by GL 95-07, Pressure Locking and Thermal Binding ofSafety-Related Power Operafed Gate Va/ves. The modification also Included a requirement toremove electrical power from each of the SDC suction isolation valve actuators by locking opentheir associated motor control circuit breakers. The intersystem-LOCA (ISLOCA) calculationswere revised to include the plant design change and show a risk increase in the ISLOCAfrequency. However, the plant design change prevents inadvertent opening of the SDC suctionvalves during power operations and improves the ability to initiate shutdown cooling operations forevents involving loss of one train of electrical power. These factors were judged to offset thecalculated risk increase such that the net change to ISLOCA is at least risk neutral.

The net effect of the modeling changes caused a slight increase in the calculated core damagefrequency (CDF). However, when the data update was completed, including all other initiatingevents, the final result was a decrease in the calculated CDF for both units. Results of theupdated calculations for the increased LPSI AOT are included in the following tables for St. LucieUnits 1 and 2. In cases where the revised numerical values differ from those shown in Tables6.3.2-1, 6.3.2-2, and 6.3.2-3 of CE NPSD-995, the original value is shown in parentheses. Theupdated St Lucie results align well with the 1995 data for the other CE units, and indicate less riskthan the original calculations for the proposed LPSI AOT.

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Table 1

AOT CONDITIONALCDF CONTRIBUTIONS FOR LPSI SYSTEM-Corrective Maintenance

(CE NPSD-995, Table 6.3.2-1 superseded values are shown in parentheses)

Parameter St. Lucie Unit 1 St. Lucie Unit 2

LPSI System Success Criteria

Current AOT, days

Proposed AOT, days

Conditional CDF, per yr.,1 LPSI train unavailable

1 of2

3.21E45 (9.0E-05)

1 of2

2.91E45 (9.1E-05)

Conditional CDF, per yr.,1 LPSI train not out for T/M

Increase in CDF, per yr.

Single AOT Risk, Current fullAOT

Single AOT Risk, Proposed full AOT

Downtime Frequency, events/yr/train

1A4E45 (2.14E-05)

1.77E45 (6.9E-05)

1.45E47 (5.7E-07)

3.39E47 (1.3E-06)

1.0 (0.5)

Yearly AOT Risk, Current fullAOT, per yr. 2.91E47 (5.7E-07)

Yearly AOT Risk, Proposed fullAOT, per yr. 6.78E47 (1.3E-06)

Mean Duration, hrs/event

Single AOT Risk for Mean Duration

24

4.85E48 (1.9E-07)

Yearly AOT Risk for Mean Duration, per yr. 9.69E48 (1.9E-07)

1.25E45 (2.35E-05)

1.66E45 (6.8E-05)

1.36E47 (5.6E-07)

3.18E47 (1.3E-06)

1.0 (0.5)

2.73E47 (5.6E-07)

6.36E47 (1.3E-06)

24

4.54E48 (1.9E-07)

9.09E48 (1.9E-07)

Per CE NPSD-995, Table 6.3.2-1, 24 hours is assumed to be a bounding value based on historic data.

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Table 2

AOT CONDITIONALCDF CONTRIBUTIONS FOR LPSI SYSTEM-Preventive Maintenance

(CE NPSD-995, Table 6.3.2-2 superseded values are shown in parentheses)



Current AOT, days

Proposed AOT, days

Conditional CDF, per yr.,1 LPSI train unavailable

Conditional CDF, per yr.,1 LPSI train not out for T/M

Increase in CDF, per yr.

Single AOT Risk, Current fullAOT

Single AOT Risk, Proposed fullAOT

Downtime Frequency, events/yr/train

1 of2

1.75E45 (3.2E-05)

1.44E45 (2.14E45)

3.1E46 (1.1E-05)

2.55E48 (9E48)

5.94E48 (2.1E-07)

3 (2)

1 of 2

1.55E45 (3.2E-05)

1.25E45 (2.35E-05)

3.00E46 (8.5E-06)

2.46E48 (7E-08)

5.75E48 (1.6E-07)

(2)

Proposed Downtime, hrs/yr/train

Mean Duration, hrs/event

Single AOT Risk for Mean Duration

208 (252)

69 (112)

2.45E48 (1.4E-07)

Yearly AOT Risk for Mean Duration, per yr. 1.47E47 (5.6E-07)

Yearly AOT Risk, Current full AOT, per yr. 1.53E47 (3.6E-07)

Yearly AOT Risk, Proposed full AOT, per yr. 3.56E47 (8.4E-07)

1.48E47 (2.8E-07)

3.45E47 (6.5E-07)

208

69

(252)

(112)

2.37E48 (1.1E-07)

1.42E47 (4.3E-07)

A mean duration of 112 hrs/event was conservatively assumed (2/3 of proposed AOT) in CE NPSD-995unless actual plant data was available.

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Page 11 of 19

Table 3

PROPOSED AVERAGE CDF's (CE NPSD-995, Table 6.3.2-3 superseded values are shown inparentheses)



Present AOT, days

Proposed AOT, days

Proposed Downtime, hrs/train/yr

Average CDF, base, per yr.

Proposed Average CDF, per yr.,using LPSI T/M set at ProposedDowntime value

1 of2

232 (276)

1.44E45 (2.14E-05)

1.45E45 (2.2E-05)

1 of2

232 (276)

1.25E45 (2.35E-05)

1.26E45 (2.4E-05)

FPL calculated the Large Early Release Frequency (LERF) and demonstrated (Table 4) that thecalculated increase in the LERF as a result of the proposed AOT meets the RG 1.174 acceptanceguideline of very small, which is taken as being less than 1E-07 per reactor year.

Table 4

PROPOSED AVERAGE LERF's

Early Containment FailureProbability = 0.01 (baseline)

* Early Containment FailureProbability = 0.1

Parameter St. Lucie Unit 1 St. Lucie Unit 2 St. Lucie Unit 1 St. Lucie Unit 2

Avg. LERF, base, per yr. 3.42E46

Proposed LERF, per yr,using LPSI T/M set atproposed downtime value 3.42E46

* Sensitivity evaluation (factor of 10 increase)

6.00EZ6

6.00E46

4.68E46

4.69E46

7.10E46

7.11E46

S t. Lucie Unit 1 and Unit 2 L-99-079Docket Nos. 50-335 and 50-389 Attachment 1

Proposed License Amendments Page 12 of 19LPSI S stem Risk Informed AOT Extension

FPL calculated the Incremental Conditional Core Damage Probability (ICCDP) for each St. Lucieunit using the methodology specified in RG 1.177 and demonstrated (Table 5) that the ICCDPmeets the acceptance guideline for a single AOT change, i.e., the AOT change has only a smallquantitative impact on plant risk defined in Part C.2.4.1 of the regulatory guide as <5E-07.

Table 5

ICCDP RESULTS (Calculated using RG 1.177 methodology)


ICCDP for Corrective Maintenance (CM) case 3.39EW7

ICCDP for Preventive Maintenance (PM) case 5.94E48

3.18E47

5.75E48

FPL calculated the Incremental Conditional Large Early Release Probability (ICLERP) for each St.Lucie unit using the methodology specified in RG 1.177 and demonstrated (Table 6) that theICLERP meets the acceptance guideline for a single AOT change, i.e., the AOT change has onlya small quantitative impact on plant risk defined in Part C.2.4.1 of the regulatory guide as <5E-08.The revised intersystem-LOCA value for PSL2 is included in calculations of the ICLERP for thatunit.

Table 6

ICLERP RESULTS (Calculated using RG 1.177 methodology)

Case

Early Containment FailureProbability = 0.01 (baseline)

St. Lucie Unit 1 St. Lucie Unit 2

* Early Containment FailureProbability = 0.1

St. Lucie Unit 1 St. Lucie Unit 2

CM 1.09E48 5.94E49

PM 1.15E49 9.58E-10

Sensitivity evaluation (factor of 10 increase)

4.08E48

6.52E49

3.43E48

6.13E49

The original analyses for PSL1 and PSL2 indicated that continued plant operation with a singleLPSI train out of service will result in a small increase in "at power risk;" however, when the fullscope of plant risk is considered, the risk incurred by extending the AOT for the performance ofmaintenance activities would be offset by risk benefits associated with averting unnecessary planttransitions to shutdown modes and/or by reducing risk during shutdown operations. In addition, theproposed AOT extension for the LPSI system was evaluated as having a negligible impact on thelarge early radiological release probability for CE Pressurized Water Reactors in the event of adesign basis accident. Based on the original results, including the sensitivity studies (PM and CMconditional CDF cases and annual CDF) and the comparison with other CE units in CE NPSD-995, the AOT extension was shown to be risk beneficial overall. The updated results, as notedabove, indicate less risk per AOT and confirm our original conclusion regarding the risk benefits ofan increased allowable outage time for the LPSI system.



Page 13 of 19

3.2.3 Summa of Results for Tier 1 2 and 3 Evaluations

Tier 1 is an evaluation of the impact on plant risk of the proposed TS change as expressed by thechange in core damage frequency, the incremental conditional change in core damageprobability, and when appropriate, the change in large early release frequency and theincremental conditional large early release probability. A series of sensitivity studies wereperformed to estimate the risk impact of the proposed AOT extension on the core damage andlarge early release frequencies. The types of sensitivity studies were developed as part of theGEOG task with input from the NRC staff.

It can be seen from the data in Tables 3 and 4 that the calculated increase in CDF is less than 1E-06 per reactor year and the calculated increase in the LERF is less than 1E-07 per reactor year,respectively. Thus, the RG 1.174 acceptance guideline of "very small" increases in theseparameters is satisfied. In addition, the calculated ICCDP (Table 5) is less than 5E-07 and thecalculated ICLERP (Table 6) is less than 5E-08, and satisfy the acceptance guideline that theproposed AOT change has only a "small" quantitative impact on plant risk as defined in RG1.177.

The PSA model used to calculate the estimated risk impact of the proposed AOT extension doesnot include an assessment of the potential risk due to internal fires and external events. The St.Lucie response to GL 88-20, Supplement 4, Individual Plant Examinafion of Exfemal Evenfs forSeven.. Accident Vulnerabilifies, (IPEEE) concluded that there are no severe accidentvulnerabilities to internal fire and external events. Based on engineering judgement, it isestimated that any potential impact the proposed AOT extension could have on the risk due tofires and external events would be very small and well within the acceptance criteria.

Tier 2 is the avoidance of risk-significant plant configurations by identification of potentially highrisk configurations that could exist if equipment in addition to that associated with the TS changeis concurrently taken out of service or other risk significant operational factors such as concurrentsystem or equipment testing are involved. The objective of Tier 2 is to ensure that appropriaterestrictions are placed on dominant risk significant configurations that would be relevant to theproposed TS change. Based on previous maintenance related risk evaluations and calculationsperformed in support of pre-evaluated maintenance risk assessment (PREMRA) matrices(discussed in Part 3.2.4 of this attachment), FPL has not identified any additional constraints orcompensatory actions that should be included with the proposed AOT extension in order to avoidplanned high risk configurations. Assessments performed in accordance with provisions of theproposed CRMP will ensure that potentially risk significant configurations are identified prior toremoving a LPSI train from service for pre-planned maintenance. Similarly, implementation of theCRMP willensure that the risk significance of unexpected configurations resulting from unplannedmaintenance or conditions while in the risk-informed AOT is properly evaluated.

Tier 3 is the development of a proceduralized program, which ensures the risk impact of out-of-service equipment is appropriately evaluated prior to performing a maintenance activity. Theprogram applies to technical specification structures, systems or components for which a risk-informed AOT has been granted. A viable program would be one that is able to uncover risk-significant plant equipment outage configurations in a timely manner during normal plant operationand is described in RG 1.177 as the CRMP. The need for this third tier stems from the difficultyofidentifying all possible risk-significant configurations under Tier 2 that will be encountered overextended periods of plant operation.



Page 14 of 19

The St: Lucie Technical. Specifications do not presently contain any AOTs that requireimplementation of a CRMP. However, an engineering Reliability and Risk Assessment Group(RRAG) and use of a proceduralized risk management process is in place. This process is usedfor evaluating planned on-line maintenance and is also used to support compliance with theMaintenance Rule. A CRMP based on the model program described in RG 1.177 will beimplemented to support the proposed and potential future risk-informed AOT extension(s). Adescription of the CRMP and its essential elements will be described in the St. Lucie PlantAdministrative Procedure that ensures compliance with the Maintenance Rule. The primary toolfor performing CRMP risk assessments for each St. Lucie unit will be the PSA-informed On-LineRisk Monitor (OLRM). The OLRM and requirements for risk assessment group specificevaluations associated with the proposed CRMP are discussed in Part 3.2.4 of this attachment.

3.2.4 Confi uration Risk Mana ement Pro ram CRMP

Regulatory Position C.2.3.7.1 of RG 1.177 states, "Licensees should describe their capability toperform a contemporaneous assessment of the overall impact on safety of proposed plantconfigurations prior to performing and during performance of maintenance activities that removeequipment from service. Licensees should explain how these tools or other processes will beused to ensure that risk-significant plant configurations will not be entered and that appropriateactions willbe taken when unforeseen events put the plant in a risk-significant configuration. TheTS Administrative Controls should describe the licensee's program for performing a real-time riskassessment. The bases for TS for which an extended AOT is granted should reference thisprogram description. The following program should be incorporated and should be described inthe TS Administrative Controls section." Regulatory Position C.2.3.7.2 states in part, "The intentof the CRMP is to implement Section a(3) of the Maintenance Rule (10 CFR 50.65) with respect toon-line maintenance for risk-informed TS, ..."

In February 1999, the first public meeting of the NRC staff's'Risk-Informed Licensing Panel washeld in Washington DC. In view of the proposed revision to the Maintenance Rule which willincorporate requirements for a CRMP, considerable debate ensued concerning the stafl's position"that the program description should be incorporated and described in the TS AdministrativeControls section, and that licensee requests for risk-informed AOT extensions should include aproposed TS for this purpose. As a result of the meeting, the staff elected to provide interimguidance for the CRMP issue, which would be developed and attached to the meeting minutes.The interim guidance would note that placing the CRMP description into a licensee-controlleddocument would be considered as a potential alternative to the RG 1.177 staff position of placingthe CRMP into the TS Administrative Controls section. The interim guidance has not beenpublished as of the date of this submittal. However, FPL was informed (telephone conferencewith the staff (N.V. Gilles) and others (OPPD, NU, ABB-CE) held on April 16, 1999) that theinterim guidance has been written and is currently in the stafl"s concurrence review process, withthe expectation that an information notice willbe issued later in 1999.

FPL proposes to include the description of the CRMP and its essential elements in the St. LuciePlant Administrative Procedure (ADM) that ensures compliance with the Maintenance Rule(currently identified as ADM-17.08, Implementation of 10 CFR 50.65, the Maintenance Rule).Except for the location of the program description, the proposed CRMP is consistent with the staffposition of RG 1.177, Part C.2.3.7, which states in part, "Consistent with the fundamental principlethat changes to TS result in small increases in the risk to public health and safety (Principle 4),certain configuration controls need to be utilized."



Page 15 of 19

3.2.4.1 Pro osed CRMP descri tion: The Configuration Risk Management Program (CRMP)provides a proceduralized risk-informed assessment to manage the risk associated withequipment inoperability. The program applies to technical specification structures,systems, or components (SSC) for which risk-informed allowed outage time has beengranted. The program is to include the following:

a. Provisions for the control and implementation of a Level 1 at-power internal.eventsPSA-informed methodology. The assessment is to be capable of evaluating theapplicable plant configuration.

b. Provisions for performing an assessment prior to entering the plant configurationdescribed by the Limiting Conditions for Operation (LCO) Action Statement for preplannedactivities.

c. Provisions for performing an assessment after entering the plant configurationdescribed by the LCO Action Statement for unplanned entry into the LCO ActionStatement.

d. Provisions for assessing the need for additional actions after the discovery of additionalequipment-out-of-service conditions while in the plant configuration described by the LCOAction Statement.

e. Provisions for considering other applicable risk-significant contributors such as Level 2issues and external events, qualitatively or quantitatively.

3.2.4.2 Ke Com onent 1 lm lementation of CRMP: The intent of the CRMP is to implementSection a(3) of the Maintenance Rule with respect to on-line maintenance for risk-informedTS (Note: Additionslclarifications from RG 1.177, Part C.2.3.7.2, are shown in italics)

a. The scope of SSCs to be included in the CRMPis all SSCs modeled in the plant PSAin addition to all SSCs considered high safety significant per Revision 2 ofRG 1.160.

The On-Line Risk Monitor (OLRM) will be the primary tool used for risk assessments insupport of the CRMP. The existing OLRM uses the Electric Power Research InstituteEOOS software and is PSA-informed. The scope of the OLRM will be modified to ensurethat all SSCs modeled in the PSA, as well as high safety signiTicant SSCs per Revision 2of RG 1.160, are considered when performing risk assessments in support of the CRMP.Consideration of high safety significant SSCs not modeled in the PSA will be addressedqualitatively. In addition, procedures applicable to the RRAG will ensure that all SSCsincluded in the PSA model, as well as all high safety significant SSCs not in the PSA, areconsidered when performing specific evaluations in support of the CRMP.

b. The CRMP assessment tool is PSA-informed and may bein the form of a ris matrix,an on-line assessment, or a direct PSA assessment.

The OLRM is PSA-informed and will be the primary tool used for risk assessments insupport of the CRMP. If the OLRM identifies a proposed maintenance activity aspotentially risk significant or if the risk assessment can not be performed using the OLRM,the engineering RRAG will provide a specific evaluation for the activity. Presently,PREMRA matrices are used to address the Maintenance Rule high safety significant

l

a>y1



Page 16 of 19

SSCs but not all SSCs modeled in the PSA. FPL will not use the PREMRA matrices forSSCs with risk-informed AOTs, and plans to remove components affected by any such TSchanges from the matrices.

c. For pie-planned entrance into the plant configuration described by a TS ActionStatement with a risk-informed AOT, a risk assessment, including, at a minimum, a searchforrisk-significant configurations, willbe performed prior to entering the action statement.

Work Control and Operations Procedures currently address requirements for performing arisk assessment when removing SSCs from service. To support the CRMP, theseprocedures will be revised to ensure that risk assessments within the scope of the CRMPare performed using the OLRM or by the engineering RRAG prior to removing thecomponents from service.

d. For unplanned entrance into the plant configuration described by a TS ActionStatement with a risk-informed AOT, a similar assessment will be performed in a timeframe defined by the plant's Conective Action Program (Criteria XVIof Appendix B to 10CFR Part 50).

Work Control and Operations Procedures will be revised to ensure that if a componentwithin the scope of the CRMP is removed from service for previously unplanned activities,a risk assessment will be performed as soon as practicable, but no later than 24 hoursafter the component was removed from service. Although it is expected that on-shiftpersonnel could perform most assessments, 24 hours is a reasonable time frame toensure adequate resources are on site to perform an assessment and is in line with theexisting Condition Report (CR) process used in the plant corrective actions program. Therisk assessment would be performed using the OLRM or by the engineering RRAG.

e. When in the plant configuration described by a TS Action Statement with a risk-informed AOT, ifadditional SSCs become inoperable or non-functional, a risk assessment,including, at a minimum, a search forrisk-significant configurations, willbe performed in atime frame defined by the plant's Corrective Action Program (Criteria XVIofAppendix B to10 CFR Part 50).

Work Control and Operations Procedures will be revised to ensure that if a componentwithin the scope of the CRMP is out of service and additional applicable SSCs becomeinoperable or non-functional, a risk assessment will be performed as soon as practicable,but no later than 24 hours after the additional SSCs were removed from service. Althoughit is expected that on-shift personnel could perform most assessments, 24 hours is areasonable time frame to ensure adequate resources are on site to perform theassessment and is in line with the existing CR process. The risk assessment would beperformed using the OLRM or by the engineering RRAG.

f. Tier 2 commitments apply only for planned maintenance, but should be evaluated aspart of the Tier 3 assessment forunplanned occunences.

As discussed above, risk assessments will be required for both pre-planned and emergentactivities within the scope of the CRMP. Based on previous maintenance related riskevaluations and calculations performed in support of PREMRA matrices, FPL has notidentified any additional constraints or compensatory actions that should be included with

. St. Lucie Unit 1 and Unit 2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension


Page 17 of 19

.the proposed AOT extension in order to avoid or reduce the probability of planned highrisk configurations. Assessments performed in accordance with provisions of the CRMPwill ensure potentially risk significant configurations are identified prior to removing acomponent within the scope of CRMP from service for pre-planned maintenance.Similarly, implementation of the CRMP will ensure that the risk significance of unexpectedconfigurations resulting from unplanned maintenance or conditions while in the risk-informed AOT is properly evaluated.

3.2.4.3 Ke Com onent 2 Control and Use of the CRMP Assessment Tool

a. Evaluation of changes in plant configuration or PSA model features will bedispositioned byimplementing PSA model changes or by the qualitative assessment ofthe impact of fhe changes on the CRMP assessment fool. This qualitative assessmentrecognizes thaf changes to fhe PSA fake time fo implement and that changes can beeffectivel compensated for without compromising the abilify to make sound engineering

judgments.

Reliability and Risk Assessment Group procedures will require periodic reviews of plantconfiguration changes for impact on the PSA model. If plant changes are determined toimpact the PSA model, the PSA analyst will estimate the potential impact on CDF and onthe CRMP risk assessment tools. The significance of the impact of any proposed changeon the PSA results will determine the schedule for update of the PSA models and theCRMP assessment tools.

b. Limitations of fhe CRMP assessment tool are identified and understood for eachspecific AOTextension.

Any specific limitations of the OLRM applicable to CRMP requirements will be identifiedand understood as part of updating the OLRM to support the CRMP. Any interimlimitations of the OLRM due to PSA changes will be brought to the attention of the WorkControl and Operations Departments, and specific evaluations will be performed by theengineering RRAG in support of the CRMP until the OLRM can be updated to address theidentified limitations.

c. Procedures exist for the control and application ofCRMP assessmenf fools, including adescription of fhe process when the plant configuration of concern is outside the scope offhe CRMP assessment fool.

Work Control and Operations Procedures will contain guidance (prior to implementing theCRMP) to inform the engineering Reliability and Risk Assessment Group if the plantconfiguration of concern is outside the scope of the OLRM. The RRAG will provide aspecific risk assessment of that configuration.

3.2.4.4 Ke Com onent 3 Level 1 Risk-Informed Assessment: The CRMP assessment foolutilizes at least a Level 1, at power, infernal evenfs PSA model. The CRMP assessmentmay use any combination of quantitative and qualitative input. CRMP assessmenfs caninclude reference to a nsk matri, pie-existing calculations, or new PSA analyses.

a. Quantitative assessments should be performed whenever necessary for sounddecision-making.



Page 18 of 19

The OLRM is PSA-informed and will be the primary tool used for risk assessments insupport of the CRMP. The PSA model is re-quantified for the plant configuration ofconcern and therefore quantitative results are provided for sound decision-making.Qualitative input is provided for those components within the scope of the CRMP butoutside the scope of the PSA model. FPL will not use the PREMRA matrices for SSCswith risk-informed AOTs, and is planning to remove components affected by any such TSchanges from the matrices.

b. When quanfifafive assessments are nof necessary for sound decision making,qualifafive assessmenfs can be performed. QualifafI've assessmenfs should considerapplicable existinginsights from previous quanfI'fafI've assessmenfs.

Prior to implementing the CRMP, Work Control, Operations, and Reliability and RiskAssessment Group Procedures will contain provisions for performing qualitative riskassessments as required.

3.2.4.5 Ke Com onent 4 Level 2 Issues and External Events: Exfemal events and Level 2issues are freafed qualitatively or quanfI'fafively, or both.

a. External events (high winds, flooding, fires, etc.) are not explicitly modeled in the St.Lucie PSA. As such, a quantitative analysis of potential risk significance from such eventscan not be readily performed. A checklist of qualitative considerations will be developedand used when performing risk assessments with the OLRM and by the engineeringRRAG.

b. For Level 2 (Containment), the potential risk impact on the large early releasefrequency is estimated as part of the OLRM results, and acceptance criteria are provided.In addition, Reliability and Risk Assessment Group Procedures address consideration ofthe potential impact on large early release when performing specific risk evaluations.

3.2.4.6 Maintenance Rule Control RG1.177 Part C.3.2: To ensure that extension of a TS AOTdoes nof degrade operational safety over time, the licensee should ensun., as part ofifsMaintenance Rule Program (10 CFR 50.65), that when equipmenf does nof meef ifsperformance criferia, the evaluation required under fhe Maintenance Rule includes priorrelated TS changes in ifs scope. If the licensee concludes fhaf the performance orcondition of TS equipmenf affected by a TS change does nof meef establishedperformance criferia, appropriafe conecfIve action should be faken in accordance wifh theMainfenance Rule. Such conecfI've acfI'on could include consideration of another TSchange fo shorten the revised AOT, or imposition ofa more resfricfive adminisfrafI've limit,iffhe licensee defermines fhisis an imporfanf factorin reversing the negative frend.

Prior to implementing the CRMP, the St. Lucie Plant Administrative Procedure (ADM) thatensures compliance with the Maintenance Rule (currently identified as ADM-17.08,Implementation of 10 CFR 50.65, the Maintenance Rule) will be revised to require reviewof prior risk-informed TS changes as part of the corrective actions for components that donot meet established performance criteria. This requirement will apply to componentswithin the scope of the CRMP, i.e., components for which a risk-informed TS change hasbeen granted.



Page 19 of 19

G.2.5 Other Considerations

The proposed changes to TS 3.5.2 Action a. are similar to the Combustion Engineering StandardTS approved for licensees for whom the risk-informed LPSI AOT has been granted, anddifferences are primarily those of structure in order to ensure the proposed action statementsremain consistent with the existing St. Lucie TS narrative format.

The editorial changes proposed for the Recirculation Actuation Signal verification test on TSpages 3/4.5-5 will ensure the explicit terms of the specification are consistent with system design,and do not change the surveillance test requirements.

The paragraph proposed for addition to Bases Section 3/4.5.2 and 3/4.5.3, ECCS Subsystems,conforms to 10 CFR 50.36(a). The summary statements are consistent with the proposedchanges to TS 3.5.2 and Regulatory Position C.2.3.7.1 of RG 1.177.

4.0 Environmental Consideration

The proposed license amendment changes requirements with respect to installation or use of afacility component located within the restricted area as defined in 10 CFR Part 20. The proposedamendment involves no significant increase in the amounts and no significant change in the typesof any eNuents that may be released offsite, and no significant increase in individual or cumulativeoccupational radiation exposure. FPL has concluded that the proposed amendment involves nosignificant hazards consideration and meets the criteria for categorical exclusion set forth in 10CFR 51.22(c)(9) and that, pursuant to 10 CFR 51.22(b), an environmental impact statement orenvironmental assessment need not be prepared in connection with issuance of the amendment.

5.0 Conclusion

The risk contributions associated with extending the AOT for a single inoperable LPSI train from 72hours to 7 days have been quantitatively evaluated using the current plant specific ProbabilisticSafety Assessment for PSL1 and PSL2. The analyses, in conjunction with CE NPSD-995, showthat the small increase in the calculated "at power risk" can be offset by averting the risk associatedwith an unnecessary plant transition to a shutdown mode, and/or reduced risk during shutdownoperations that can result from improved flexibility in scheduling and performing surveillance andmaintenance activities.

The integrated assessment reported in CE NPSD-995, as supplemented by this submittal,generally conforms to guidance provided in NUREG/CR-6141, Handbook of Methods for RiskBased Analyses of Technical Specifications, December 1994, and, except for the location of theCRMP description, USNRC Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, August 1998. Relative to the average CoreDamage Frequency calculated for the appropriate severe accidents, NUREG/CR-6141 states, "Arisk-based AOT assures that the single event and yearly AOT risk contributions are acceptable."FPL believes the proposed 7-day AOT qualifies as a beneficial risk-based AOT, and that theproposed amendment is acceptable.

St. Lucie Unit 1 and Unit 2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension

L-99-079 ATTACHMENT2

DETERMINATIONOF NO SIGNIFICANTHAZARDS CONSIDERATION

4

Tq

4'e

~ ~

St. Lucie Unit 1 and Unit 2Docket Nos. 50-335 and 50-389Pro'posed License AmendmentsLPSI S stem Risk Informed AOT Extension

L-99-079Attachment 2Page 1 of2

DETERMINATIONOF NO SIGNIFICANTHAZARDS CONSIDERATION

Description of amendment request: The proposed amendments will revise TS 3.5.2, ECCSSubsystems —Tavg t 325'F, for both St. Lucie units, to extend the existing 72-hour actioncompletion/allowed outage time (AOT) for a single inoperable Low Pressure Safety Injection (LPSI)train to 7 days. The proposed 7-day action is a risk-informed AOT. Minor editorial changes for thespecified Recirculation Actuation Signal (RAS) verification test are also included to ensure theterminology used in the specification is consistent with plant design.

Pursuant to 10CFR50.92, a determination may be made that a proposed license amendmentinvolves no significant hazards consideration if operation of the facility in accordance with theproposed amendment would not: (1) involve a significant increase in the probability orconsequences of an accident previously evaluated; or (2) create the possibility of a new or differentkind of accident from any accident previously evaluated; or (3) involve a significant reduction in amargin of safety. Each standard is discussed as follows:

(1) Operation of the facility in accordance with the proposed amendment would not involvea significant increase in the probability or consequences of an accident previouslyevaluated.

The proposed amendments for St. Lucie Unit 1 and Unit 2 will extend the actioncompletion/allowed outage time (AOT) for a single inoperable Low Pressure Safety Injection (LPSI)train from 72 hours to 7 days. A LPSI train is designed as a part of each Emergency Core CoolingSystem (ECCS) subsystem to supplement Safety Injection Tank (SIT) inventory during the earlystages of mitigating a Design Basis Accident. As such, components of the LPSI system are notaccident initiators, and an extended AOT to restore operability of an inoperable LPSI train wouldnot increase the probability of occurrence of accidents previously analyzed.

The safety analyses for both St: Lucie Units demonstrate that ECCS performance acceptancecriteria are satisfied with only one of the two redundant ECCS subsystems operating during thepostulated Design Basis Accident. The proposed technical specification revisions involve the AOTfor a single inoperable LPSI train, and do not change the conditions assumed for the minimumamount of operating equipment needed for accident mitigation. Therefore, the consequences of anaccident previously evaluated will not be significantly increased.

In addition to the preceding evaluation, a Probabilistic Safety Analysis (PSA) was performed toquantitatively assess the risk impact of the proposed amendments. It was concluded from theresults of that assessment that the risk contribution of the AOT extension is very small, and that thenet impact of the proposed amendment can be risk beneficial.

The editorial corrections proposed for the specified RAS verification test do not alter existing testrequirements and have no impact on the accident analyses.

St. Lucie Unit1 and Unit 2Docket Nos. 50-335 and 50-389Proposed License AmendmentsLPSI S stem Risk Informed AOT Extension

L-99-079Attachment 2Page 2 of2

Therefore, operation of either facility in accordance with its proposed amendment would not involvea significant increase in the probability or consequences of an accident previously evaluated.

(2) Operation of the facility in accordance with the proposed amendment would not createthe possibility of a new or different kind of accident from any accident previously evaluated.

The proposed amendments will not change the physical plant or the modes of plant operationdefined in either Facility License. The changes do not involve the addition or modification ofequipment nor do they alter the design of plant systems. Therefore, operation of either facility inaccordance with its proposed amendment would not create the possibility of a new or different kindof accident from any accident previously evaluated.

(3) Operation of the facility in accordance with the proposed amendment would not involvea significant reduction in a margin of safety.

The margin of safety associated with the ECCS system is established by acceptance criteria forsystem performance defined in 10 CFR 50.46. The proposed amendments will not'change theseacceptance criteria or the operability requirements for equipment that is used to achieve suchperformance as demonstrated in the plant safety analyses. Moreover, an integrated assessmentof the risk impact of extending the AOT for a single inoperable LPSI train has concluded that therisk contribution is very small, LPSI system reliability can potentially be improved, and the netimpact of the proposed change can be risk beneficial. The editorial corrections proposed for thespecified RAS verification test do not alter existing test requirements and have no impact on theaccident analyses. Therefore, operation of either facility in accordance with its proposedamendment would not involve a significant reduction in a margin of safety.

Based on the above discussion and the supporting Evaluation of Proposed Technical SpecificationChanges, FPL has determined that the proposed license amendments involve no significanthazards consideration.

Documents

Application for amends to licenses DPR-67 & NPF-16 ... · c.St. Lucie Unit1 and Unit2 Docket Nos. 50-335 and 50-389 Proposed License Amendments LPSI S stem Risk Informed AOT Extension