Text

Application for Amends to Licenses DPR-67 & NPF-16,revising TS 3.5.2 to Allow Up to 7 Days to Restore Inoperable LPSI Train to Operable Status
	ML17241A352
Person / Time
Site:	Saint Lucie
Issue date:	06/01/1999
From:	Stall J; FLORIDA POWER & LIGHT CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17241A353	List: ML17241A352; ML17241A354;
References
	L-99-079, L-99-79, NUDOCS 9906090019
	Download: ML17241A352 (35)
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CATZaoax 1 REGULA' INFORMATION DISTRIBUTI . SYSTEM (RIDS)

ACCESSION NBR:9906090019 DOC.DATE: 99/06/01 NOTARIZED: YES DOCKET FACXL:5'-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335

,$ 0-.389 St. Lucie Plant, Unit 2, Florida Power 8 Light Co. 05000389 ASH';NAME AUTHOR AFFILIATION STA/L,J.A. Florida Power E Light Co.

RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)

SUBJECT:

Application for amends to licenses DPR-67 & NPF-16,revising TS 3.5.2 to allow up to 7 days to restore inoperable LPSI train to operable status.

DISTRIBUTION CODE: AOOID TITLE: OR COPIES RECEIVED:LTR Submittal: General Distribution L ENCL 1 SIZE:

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL LPD2-2 LA 1 1 LPD2-2 PD 1 1 GLEAVES,W 1 1 R INTERNAL: ACRS 1 1 E CENTER 01 1 1 NRR/DE/EEXB 1 1 NRR ITT 1 1 NRR/DE/EMEB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NRR/SPSB JUNG,I 1 1 NUDOCS-ABSTRACT 1 1 OGC/RP 1 0 EXTERNAL: NOAC 1 1 NRC PDR D

'E NOTE TO ALL "RZDS" RECIPIENTS:

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Florida Power & Light Company, 6351 S. Ocean Drive, Jensen Beach, FL34S57 June 1999 L-99-079 1,

10 CFR 50.90 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 RE: St. Lucie Unit 1 and Unit 2 Docket Nos. 50-335 and 50-389 Proposed License Amendments LPSI S stem Risk Informed AOT Extension Pursuant to 10 CFR 50.90, Florida Power 8 Light Company (FPL) requests to amend Facility Operating Licenses DPR-67 and NPF-16 for St. Lucie Unit 1 and Unit 2, respectively, by incorporating the attached Technical Specifications (TS) revisions. The amendments will revise TS 3.5.2 to allow up to 7 days to restore an inoperable Low Pressure Safety Injection (LPSI) train to operable status. The proposed action completion/allowed outage time (AOT) will enhance overall plant safety by avoiding potential unscheduled plant shutdowns, and by providing increased flexibilityfor scheduling and performing maintenance activities. The risk-informed AOT is 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 Safety Assessment (PSA) model for each St. Lucie unit. The results of these improvements relative to the LPSI AOT are provided herein and supersede the corresponding plant-specific information in CE NPSD-995. It is requested that the proposed amendments be issued by February 29, 2000. is an evaluation of the proposed changes. Attachment 2 is the "Determination of No Significant Hazards Consideration." Attachments 3 and 4 contain copies of the appropriate technical specifications pages marked up to show the proposed changes. The St. Lucie Facility Review Group and the FPL Company Nuclear Review Board have reviewed the proposed amendments, and a copy of this submittal is being forwarded to the State Designee for the State of 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. Stall Vice President St. Lucie Plant JAS/RLD 990S0900<9 ~ego~

Attachments PDR ADOCK 05000335 p PDR ~i CC:

Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant Mr. W.A. Passetti, Florida Department of Health and Rehabilitative Services an FPL Group company

St. Lucie Unit1 and Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Page 2 Proposed License Amendments LPSI S stem Risk Informed AOT Extension STATE OF FLORIDA )

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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 & Light Company, the Licensee herein; That he has executed the foregoing document; that the statements made in this document are true and correct to the best of his knowledge, information and belief, and that he is authorized to execute 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 Florida Leslle J. Whltwell MY COMMISSION 4 CCQ6183 EXPIRES May 12, 2001 80NOED 1HRU TROY FAN ICSRA!CE, INC.

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

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St. Lucie Unit 1 and Unit 2 Docket Nos. 50-335 and 50-389 Proposed License Amendments LPSI S stem Risk Informed AOT Extension L-99-079 ATTACHMENT1 EVALUATIONOF PROPOSED TS CHANGES 1.0 Introduction 2.0 Background 2.1 Low Pressure Safety Injection (LPSI) System 2.2 Technical Specification (TS) 3.5.2, ECCS Subsystems Tavg ~ 325'F 2.3 Previous FPL Correspondence Related to the Proposed Amendments 3.0 Proposed TS Changes: Description and Bases/Justification 3.1 Description of TS Changes 3.2 Basis for Proposed Changes 3.2.1 Deterministic Assessment of LPSI AOT Extension 3.2.2 Piobabilistic Safety Assessment of LPSI AOT Extension 3.2.3 Summary of Results for Tier 1, 2, and 3 Evaluations 3.2.4 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 Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 1 of 19 LPSI S stem Risk Informed AOT Extension EVALUATIONOF PROPOSED TS CHANGES 1.0 Introduction Florida Power and Light Company (FPL) requests that Appendix A of Facility Operating License DPR-67 for St. Lucie Unit 1 (PSL1) and NPF-16 for St. Lucie Unit 2 (PSL2) be revised to extend the action completion/allowed outage time (AOT) for an inoperable Low Pressure Safety Injection (LPSI) train from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days. The AOT extension will enhance overall plant safety by avoiding potential unscheduled plant shutdowns, and by providing increased flexibility for scheduling and performing maintenance activities. The proposed AOT is based on the results of a cooperative study performed by participating members of the Combustion Engineering Owners Group (GEOG) in conjunction with information provided herein. The study included an integrated review and assessment of plant operations, deterministic design basis factors, and overall plant risk using probabilistic safety assessment (PSA) techniques.

The NRC has been reviewing and granting improvements to technical specifications (TS) that are based, at least in part, on probabilistic risk assessment insights since the mid-1980's. In concert with this initiative, the GEOG submitted several joint application reports that provide justifications for TS AOT extensions to the NRC staff for generic review (GEOG Letter 95-344, D.F. Pilmer to NRC Document Control Desk, C-E Owners Group Submiffal of Joint Appircaffon Reports, July 10, 1995). The justifications for these extensions are based on a balance of probabilistic and traditional engineering considerations, and risk assessments for the participating Combustion Engineering (CE) plants are contained in the reports. St. Lucie Unit 1 and Unit 2 were participating plants in that owner's group task, and the report pertinent to this submittal is CE NPSD-995, Joint Appir'cafions Report for Low Pressure Safefy Injection System AOT Extension; ABB-Combustion Engineering Inc., May 1995. A license amendment request based on CE NPSD-995, as supplemented 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 redundant subsystems, and each subsystem includes a LPSI train in combination with a High Pressure Safety Injection (HPSI) train. The plant specific safety analyses for PSL1 and PSL2 demonstrate that either 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 the Safety Injection Tank (SIT) inventory in re-flooding the reactor vessel with borated water during the early stages of a large break Loss of Coolant Accident (LOCA). The LPSI system is actuated by an automatic or manually initiated Safety Injection Actuation Signal (SIAS) which starts the associated pump and causes the LPSI flow control valves to open. The LPSI pumps transfer borated water from the Refueling Water Tank (RWT), through the LPSI header(s), and into the safety injection penetrations to the Reactor Coolant System (RCS) cold legs. During the recirculation phase of the LOCA scenario, the LPSI pumps are stopped by an automatic or manually initiated Recirculation Actuation Signal (RAS) and long term core cooling is supplied by

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St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 2 of 19 LPSI S stem Risk Informed AOT Extension the HPSI pumps taking suction from the containment sump. The LPSI systems for both St. Lucie units are functionally the same, but contain differences in the piping arrangement, e.g., PSL1 has a common LPSI header which branches out to each of the four high pressure cold leg penetrations whereas PSL2 has two independent LPSI headers, each branching out to two of the high pressure cold leg penetrations.

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

Detailed descriptions of the LPSI systems are contained in Section 6.3 of the Updated Final Safety Analysis Report (UFSAR) for each St. Lucie unit. Shutdown cooling operations are described in UFSAR 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 in Mode 3 when RCS pressure is z 1750 psia. In the event one of the ECCS subsystems becomes inoperable, the Limiting Condition for Operation (LCO) requires the inoperable subsystem to be restored to operable status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or the plant must transition to Mode 4 (Hot Shutdown) within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . If both ECCS subsystems become inoperable, action must be initiated in compliance with TS 3.0.3, which would ultimately lead to the cold shutdown condition. The prescribed 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months AOT is based on an NRC study, circa 1975, "using a reliability evaluation [of ECCS 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 ensure that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of one subsystem through any single failure consideration. Either subsystem operating in conjunction with the safety injection tanks is capable of supplying sufficient core cooling to limit the peak cladding temperatures within the acceptance criteria for all postulated break sizes ranging from the double-ended break of the largest RCS hot Ieg pipe downward. In addition, each ECCS subsystem provides long-term core cooling capability in the recirculation mode during the accident recovery period. In Mode 3 with RCS pressure < 1750 psia and in Mode 4, one operable ECCS subsystem is acceptable without single failure consideration based on the stable reactivity condition of the reactor and the limited core cooling requirements.

~ St. Lucie Unit1 and Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 3 of 19 LPSI S stem Risk Informed AOT Extension 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 License Amendments, LPSI System AOT Extension; June 22, 1995. CE NPSD-995, Joint Applications Report for Low Pressure Safety Injection System AOT Extension: ABB Combustion 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 of Proposed License Amendments for LPSI and EDG Risk Informed Technical Specifications; December 15, 1998 was issued, in part, to withdraw FPL's previous request to extend the TS 3.5.2 AOT for an inoperable LPSI train. This letter resulted from several changes that had occurred subsequent to the original submittal: (a) formal guidelines that were being developed during and after the time of FPL's submittal were issued, e.g., USNRC Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, August 1998; (b) improved input data was developed and enhancements were made to the St. Lucie PSA models; and (c) improvements to the St. Lucie plant configuration risk management process were being developed.

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 affected TS 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 associated LPSI train is inoperable, restore the inoperable subsystem to OPERABLE status within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

a.2. With one ECCS subsystem inoperable for reasons other than condition a.1., restore the inoperable subsystem to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

h i h 4, ill b the 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 the following paragraph:

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+St. Lucie Unit1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 4 of 19 LPSI S stem Risk Informed AOT Extension "TS 3.5.2, ACTION a.1. provides an allowed outage/action completion time (AOT) of up to 7 days from initial discovery of failure to meet the LCO provided the affected ECCS subsystem is inoperable only because its associated LPSI train is inoperable. This 7 day AOT is based on the findings of a deterministic and probabilistic safety analysis and is referred to as a "risk-informed" AOT extension. Entry into this ACTION requires that a risk assessment be performed in accordance with the Configuration Risk Management Program (CRMP), which is described in the Administrative Procedure (ADM-17.08) that implements 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 a portion of the ECCS, and TS 3.5.2 requires two independent ECCS subsystems to be operable in Modes 1, 2, and 3 when RCS pressure is 2 1750 psia. With one ECCS subsystem inoperable, that subsystem must be returned to operable status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or a plant shutdown to Mode 4 is required. If both ECCS subsystems become inoperable, action must be initiated in compliance with TS 3.0.3, which would ultimately lead to the cold shutdown condition. The proposed change applies to the case where one ECCS subsystem becomes inoperable, and will allow up to 7 days to restore that subsystem to operable status, provided the subsystem is inoperable only because a LPSI train is inoperable.

In the upper operating modes, LPSI trains must be available in the event that LOCA mitigation becomes 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 and lower. In contrast, at least one LPSI train is required to be operable for RCS heat removal during normal shutdown operations in Modes 4, 5, and 6, and is almost always in operation when in these modes. Therefore, in the broad view, performing preventive and corrective maintenance on LPSI trains when at power can enhance overall plant safety by increasing the availability and reliability of the 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 associated valves 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 plant shutdown or a request for temporary relief to allow continued plant operation. Based on a review of the maintenance requirements of LPSI systems for CE pressurized water reactors, the GEOG study described in CE NPSD-995 concluded that a 7-day AOT would provide sufficient margin to effect most anticipated preventive and corrective maintenance activities and LPSI system surveillance 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 a given ECCS design relative to reactor core cooling performance during postulated LOCAs. The ECCS cooling performance for each St. Lucie unit is calculated using acceptable evaluation

~ St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 5 of 19 LPSI S stem Risk Informed AOT Extension models that are designed pursuant to 10 CFR 50, Appendix K, and satisfies all of the 10 CFR 50.46 acceptance criteria. The required and acceptable features of Appendix K evaluation models ensure that thermohydraulic and hydrodynamic phenomena are conservatively represented in the calculations of peak cladding temperature (PCT), and the methodology provides assurance that the minimum equipment requirements for adequate response to design basis LOCAs are conservative. The PSL1 and PSL2 safety analyses demonstrate that a single train of ECCS equipment operating in conjunction with safety injection tanks provides an adequate and conservative 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 typical pressurized water reactor (PWR) suggest that the Appendix K methodology may result in overstating the minimum equipment requirements for adequate LOCA response. In the example given for large break LOCAs, incipient core melt could be averted by operating combinations of ECCS 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 provide adequate response to a design basis large LOCA scenario. For each St. Lucie unit, major ECCS components include four passively actuated SITs, two HPSI pumps, and two LPSI pumps, and the proposed AOT extension from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days will be permitted in a condition where only one LPSI train is inoperable. If an ECCS subsystem becomes inoperable for any other reason, the existing 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months AOT must be applied. If both ECCS subsystems are inoperable, power operation is 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 for RCS inventory control, the HPSI system functions to keep the reactor core covered. The LPSI system is only required as part of the SDC system which is used for RCS and core heat removal after the initial transient and radioactive releases have been controlled. Loss of both LPSI trains is beyond design basis accident assumptions and the proposed AOT extension does not change the design basis for these events. However, in the unlikely event that one I PSI train is out of service and the second LPSI train fails, the defense-in-depth principle ensures that operators can continue to control and satisfy the RCS and Core Heat Removal safety function by steaming one or both steam 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 capabilities for 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 116,000 gallons and 307,000 gallons, respectively. However, the steam generator heat sink can be maintained indefinitely provided make-up condensate remains available to the Condensate Storage Tank (CST). Plant procedures provide instructions for replenishing condensate inventory storage, and also include instructions for supplying the PSL1 Auxiliary Feedwater Pumps from the PSL2-CST in the event that the smaller PSL1-CST becomes unavailable. Extending the LPSI AOT would not impact this defense-in-depth capability.

The methodology, assumptions, and results of calculations performed to conservatively assess the radiological 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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.. St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 6 of 19 LPSI S stem Risk Informed AOT Extension generally considered that the potential for accident initiation within the brief time intervals conditionally allowed by the TS for return of inoperable safety-related equipment to operable status is sufficiently small to justify continued power operations during those intervals. However, the impact of an AOT interval on the probability and estimated frequency of large radiological releases can be quantified in a probabilistic framework by using PSA techniques to evaluate the risk associated with continued plant operations during periods of equipment inoperability. Part 6.2.2 of the joint applications report, CE NPSD-995, provides a discussion of the radiological release considerations included in the GEOG study. The report concludes that potential releases would remain within 10 CFR 100 limits in the unlikely event that a design basis accident occurred in the presence of a compromised ECCS, i.e., no LPSI.

~Summa: Based on recent best estimate analyses for a typical PWR, the design basis LOCA requirement for one LPSI train, one HPSI train, and all SITs to avert a core melt condition is considered conservative in that design basis ECCS acceptance criteria could be met if a LOCA occurred at a time when one LPSI train is out of service. The LPSI system is not required for a non-LOCA event until such time as the event has been brought under control and the plant is at the low 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. In addition to the accident considerations, the fact that the LPSI system is required for decay heat removal every time the plant is placed in cold shutdown indicates that it would be prudent to perform maintenance on the LPSI system during power operations rather than during shutdown when the demand for the system is at its highest. Therefore, extending the AOT for one inoperable LPSI train from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days should continue to ensure defense-in-depth is maintained and sufficient 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 with the plant design bases, a probabilistic safety assessment of risks involved with applicable plant operations was also performed by FPL. The assessment generally conforms to the three-tiered approach to an evaluation of the risk impact from an AOT extension that is identified in Regulatory Position C.2.3 of USNRC Regulatory Guide 1.177, An Approach for Planf-Specific, Risk-Infolmed Decisionmaking: 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 Configuration Risk Management. A summary of the results of this approach is provided in Part 3.2.3 of this attachment.

The considerations, assumptions, methodologies, and detailed results of the initial risk assessment are reported in CE NPSD-995, Joint Applicafions Report for Low Passu>8 Safety Injection System AOT Exfension, Final Report GEOG Task 836, prepared for the CE Owners Group, May 1995, as supplemented 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 AOT extension that is applicable to both St. Lucie units. The joint applications report, as supplemented,

-'t. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 7 of 19 LPSI S stem Risk Informed AOT Extension in conjunction with the improved data and PSA model enhancements that have been incorporated subsequent to 1995 as described in the following paragraphs, forms the risk-informed justification/basis for the proposed license amendments.

The St. Lucie contribution to the 1995 preparation of CE NPSD-995 was generated using the IPE models developed in response to Generic Letter (GL) 88-20, Individual Plant Examinafion for Severe Accident Vulnerabilifies, and associated supplements. Subsequently in 1997, the NRC completed 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 concluded that the FPL IPE process is capable of identifying the most likely severe accidents and severe accident 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 risk numbers for the units. The most significant change included with each model update is the creation of a "one-top" model which is constructed from the original model's individual top events for various initiators, e.g., small LOCA, large LOCA, SGTR, reactor trips, etc. The one-top model allows rapid quantification, and each case for this re-evaluation of LPSI was individually quantified. The truncation used for quantification was 2E-10 or lower. This replaces the use of one 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 implemented since creation of the original models. Due to the maturity of the St. Lucie units, only one plant design 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/unavailability database update, FPL was able to use the last three years of data gathered pursuant to the Maintenance Rule (10 CFR 50.65) which provided concise, high quality unavailability and reliability data for the risk significant systems. Outside peer review was not performed for the update because creating a one-top model essentially involved combining the existing tops for the various 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 the LPSI AOT extension follows:

Test & Maintenance (T&M) events for selected equipment were added to better support Maintenance Rule implementation and related risk evaluations. Minor improvements were made in 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 accordance with 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, the net impact was an increase in the total LOCA IE frequency of nearly 48%, i.e., from 2.09E-3 to 3.09E-3 per year.

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

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~ St. Lucie Unit1 and Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 8 of 19 LPSI S stem Risk Informed AOT Extension scenarios are recovered automatically. This automatic feature ensures uniform and complete inclusion of recovery actions throughout all of the generated cutsets, and yields more realistic and consistent results.

FPL re-evaluated all offsite power recovery cases for both St. Lucie units. One case was added to the Unit 1 analysis for recovery of offsite power in 9 hours1.041667e-4 days 0.0025 hours 1.488095e-5 weeks 3.4245e-6 months (approximately 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months before the Unit 1 CST would deplete without condensate replenishment). The non-recovery probability for one case was increased for both units due to an incorrect assumption that was used in the original analysis. In addition, the related recovery for getting power from the alternate unit was increased due to timing considerations. Although 60 minutes total is available (as assumed in the original evaluation), only 45 minutes remains for power recovery after diagnosis of the event per the plant Emergency Procedures. This factor was combined with hardware related failures to calculate the total 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 to be locked open. The valve was normally closed during power operations, and this action was taken in response to concerns raised by GL 95-07, Pressure Locking and Thermal Binding of Safety-Related Power Operafed Gate Va/ves. The modification also Included a requirement to remove electrical power from each of the SDC suction isolation valve actuators by locking open their associated motor control circuit breakers. The intersystem-LOCA (ISLOCA) calculations were revised to include the plant design change and show a risk increase in the ISLOCA frequency. However, the plant design change prevents inadvertent opening of the SDC suction valves during power operations and improves the ability to initiate shutdown cooling operations for events involving loss of one train of electrical power. These factors were judged to offset the calculated 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 damage frequency (CDF). However, when the data update was completed, including all other initiating events, the final result was a decrease in the calculated CDF for both units. Results of the updated calculations for the increased LPSI AOT are included in the following tables for St. Lucie Units 1 and 2. In cases where the revised numerical values differ from those shown in Tables 6.3.2-1, 6.3.2-2, and 6.3.2-3 of CE NPSD-995, the original value is shown in parentheses. The updated St Lucie results align well with the 1995 data for the other CE units, and indicate less risk than the original calculations for the proposed LPSI AOT.

. St. Lucie Unit1 and Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 9 of 19 LPSI S stem Risk Informed AOT Extension 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 1 of2 1 of2 Current AOT, days Proposed AOT, days Conditional CDF, per yr.,

1 LPSI train unavailable 3.21E45 (9.0E-05) 2.91E45 (9.1E-05)

Conditional CDF, per yr.,

1 LPSI train not out for T/M 1A4E45 (2.14E-05) 1.25E45 (2.35E-05)

Increase in CDF, per yr. 1.77E45 (6.9E-05) 1.66E45 (6.8E-05)

Single AOT Risk, Current full AOT 1.45E47 (5.7E-07) 1.36E47 (5.6E-07)

Single AOT Risk, Proposed full AOT 3.39E47 (1.3E-06) 3.18E47 (1.3E-06)

Downtime Frequency, events/yr/train 1.0 (0.5) 1.0 (0.5)

Yearly AOT Risk, Current full AOT, per yr. 2.91E47 (5.7E-07) 2.73E47 (5.6E-07)

Yearly AOT Risk, Proposed full AOT, per yr. 6.78E47 (1.3E-06) 6.36E47 (1.3E-06)

Mean Duration, hrs/event 24 24 Single AOT Risk for Mean Duration 4.85E48 (1.9E-07) 4.54E48 (1.9E-07)

Yearly AOT Risk for Mean Duration, per yr. 9.69E48 (1.9E-07) 9.09E48 (1.9E-07)

Per CE NPSD-995, Table 6.3.2-1, 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is assumed to be a bounding value based on historic data.

St. Lucie Unit1 and Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 10 of 19 LPSI S stem Risk Informed AOT Extension Table 2 AOT CONDITIONALCDF CONTRIBUTIONS FOR LPSI SYSTEM-Preventive Maintenance (CE NPSD-995, Table 6.3.2-2 superseded values are shown in parentheses)

Parameter St. Lucie Unit 1 St. Lucie Unit 2 LPSI System Success Criteria 1 of2 1 of 2 Current AOT, days Proposed AOT, days Conditional CDF, per yr.,

1 LPSI train unavailable 1.75E45 (3.2E-05) 1.55E45 (3.2E-05)

Conditional CDF, per yr.,

1 LPSI train not out for T/M 1.44E45 (2.14E45) 1.25E45 (2.35E-05)

Increase in CDF, per yr. 3.1E46 (1.1E-05) 3.00E46 (8.5E-06)

Single AOT Risk, Current full AOT 2.55E48 (9E48) 2.46E48 (7E-08)

Single AOT Risk, Proposed full AOT 5.94E48 (2.1E-07) 5.75E48 (1.6E-07)

Downtime Frequency, events/yr/train 3 (2) (2)

Yearly AOT Risk, Current full AOT, per yr. 1.53E47 (3.6E-07) 1.48E47 (2.8E-07)

Yearly AOT Risk, Proposed full AOT, per yr. 3.56E47 (8.4E-07) 3.45E47 (6.5E-07)

Proposed Downtime, hrs/yr/train 208 (252) 208 (252)

Mean Duration, hrs/event 69 (112) 69 (112)

Single AOT Risk for Mean Duration 2.45E48 (1.4E-07) 2.37E48 (1.1E-07)

Yearly AOT Risk for Mean Duration, per yr. 1.47E47 (5.6E-07) 1.42E47 (4.3E-07)

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

0 St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 11 of 19 LPSI S stem Risk Informed AOT Extension Table 3 PROPOSED AVERAGE CDF's (CE NPSD-995, Table 6.3.2-3 superseded values are shown in parentheses)

Parameter St. Lucie Unit 1 St. Lucie Unit 2 LPSI System Success Criteria 1 of2 1 of2 Present AOT, days Proposed AOT, days Proposed Downtime, hrs/train/yr 232 (276) 232 (276)

Average CDF, base, per yr. 1.44E45 (2.14E-05) 1.25E45 (2.35E-05)

Proposed Average CDF, per yr.,

using LPSI T/M set at Proposed Downtime value 1.45E45 (2.2E-05) 1.26E45 (2.4E-05)

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

Table 4 PROPOSED AVERAGE LERF's Early Containment Failure

Early Containment Failure Probability = 0.01 (baseline) Probability = 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 6.00EZ6 4.68E46 7.10E46 Proposed LERF, per yr, using LPSI T/M set at proposed downtime value 3.42E46 6.00E46 4.69E46 7.11E46

Sensitivity evaluation (factor of 10 increase)

S t. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 12 of 19 LPSI S stem Risk Informed AOT Extension FPL calculated the Incremental Conditional Core Damage Probability (ICCDP) for each St. Lucie unit using the methodology specified in RG 1.177 and demonstrated (Table 5) that the ICCDP meets the acceptance guideline for a single AOT change, i.e., the AOT change has only a small quantitative 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)

Parameter St. Lucie Unit 1 St. Lucie Unit 2 ICCDP for Corrective Maintenance (CM) case 3.39EW7 3.18E47 ICCDP for Preventive Maintenance (PM) case 5.94E48 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 the ICLERP meets the acceptance guideline for a single AOT change, i.e., the AOT change has only a 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 that unit.

Table 6 ICLERP RESULTS (Calculated using RG 1.177 methodology)

Early Containment Failure

Early Containment Failure Probability = 0.01 (baseline) Probability = 0.1 Case St. Lucie Unit 1 St. Lucie Unit 2 St. Lucie Unit 1 St. Lucie Unit 2 CM 1.09E48 5.94E49 4.08E48 3.43E48 PM 1.15E49 9.58E-10 6.52E49 6.13E49 Sensitivity evaluation (factor of 10 increase)

The original analyses for PSL1 and PSL2 indicated that continued plant operation with a single LPSI train out of service will result in a small increase in "at power risk;" however, when the full scope of plant risk is considered, the risk incurred by extending the AOT for the performance of maintenance activities would be offset by risk benefits associated with averting unnecessary plant transitions to shutdown modes and/or by reducing risk during shutdown operations. In addition, the proposed AOT extension for the LPSI system was evaluated as having a negligible impact on the large early radiological release probability for CE Pressurized Water Reactors in the event of a design basis accident. Based on the original results, including the sensitivity studies (PM and CM conditional 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 noted above, indicate less risk per AOT and confirm our original conclusion regarding the risk benefits of an increased allowable outage time for the LPSI system.

~

St. Lucie Unit1 and Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 13 of 19 LPSI S stem Risk Informed AOT Extension 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 the change in core damage frequency, the incremental conditional change in core damage probability, and when appropriate, the change in large early release frequency and the incremental conditional large early release probability. A series of sensitivity studies were performed to estimate the risk impact of the proposed AOT extension on the core damage and large early release frequencies. The types of sensitivity studies were developed as part of the GEOG 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 these parameters is satisfied. In addition, the calculated ICCDP (Table 5) is less than 5E-07 and the calculated ICLERP (Table 6) is less than 5E-08, and satisfy the acceptance guideline that the proposed AOT change has only a "small" quantitative impact on plant risk as defined in RG 1.177.

The PSA model used to calculate the estimated risk impact of the proposed AOT extension does not 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 for Seven.. Accident Vulnerabilifies, (IPEEE) concluded that there are no severe accident vulnerabilities to internal fire and external events. Based on engineering judgement, it is estimated that any potential impact the proposed AOT extension could have on the risk due to fires 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 high risk configurations that could exist if equipment in addition to that associated with the TS change is concurrently taken out of service or other risk significant operational factors such as concurrent system or equipment testing are involved. The objective of Tier 2 is to ensure that appropriate restrictions are placed on dominant risk significant configurations that would be relevant to the proposed TS change. Based on previous maintenance related risk evaluations and calculations performed 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 or compensatory actions that should be included with the proposed AOT extension in order to avoid planned high risk configurations. Assessments performed in accordance with provisions of the proposed CRMP will ensure that potentially risk significant configurations are identified prior to removing a LPSI train from service for pre-planned maintenance. Similarly, implementation of the CRMP will ensure that the risk significance of unexpected configurations resulting from unplanned maintenance 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. The program 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 operation and is described in RG 1.177 as the CRMP. The need for this third tier stems from the difficulty of identifying all possible risk-significant configurations under Tier 2 that will be encountered over extended periods of plant operation.

~ St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 14 of 19 LPSI S stem Risk Informed AOT Extension The St: Lucie Technical. Specifications do not presently contain any AOTs that require implementation 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 used for evaluating planned on-line maintenance and is also used to support compliance with the Maintenance Rule. A CRMP based on the model program described in RG 1.177 will be implemented to support the proposed and potential future risk-informed AOT extension(s). A description of the CRMP and its essential elements will be described in the St. Lucie Plant Administrative Procedure that ensures compliance with the Maintenance Rule. The primary tool for performing CRMP risk assessments for each St. Lucie unit will be the PSA-informed On-Line Risk Monitor (OLRM). The OLRM and requirements for risk assessment group specific evaluations 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 to perform a contemporaneous assessment of the overall impact on safety of proposed plant configurations prior to performing and during performance of maintenance activities that remove equipment from service. Licensees should explain how these tools or other processes will be used to ensure that risk-significant plant configurations will not be entered and that appropriate actions will be taken when unforeseen events put the plant in a risk-significant configuration. The TS Administrative Controls should describe the licensee's program for performing a real-time risk assessment. The bases for TS for which an extended AOT is granted should reference this program description. The following program should be incorporated and should be described in the TS Administrative Controls section." Regulatory Position C.2.3.7.2 states in part, "The intent of the CRMP is to implement Section a(3) of the Maintenance Rule (10 CFR 50.65) with respect to on-line maintenance for risk-informed TS, ..."

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

FPL proposes to include the description of the CRMP and its essential elements in the St. Lucie Plant 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 staff position of RG 1.177, Part C.2.3.7, which states in part, "Consistent with the fundamental principle that changes to TS result in small increases in the risk to public health and safety (Principle 4),

certain configuration controls need to be utilized."

~ St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 15 of 19 LPSI S stem Risk Informed AOT Extension 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 with equipment inoperability. The program applies to technical specification structures, systems, or components (SSC) for which risk-informed allowed outage time has been granted. The program is to include the following:

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

b. Provisions for performing an assessment prior to entering the plant configuration described by the Limiting Conditions for Operation (LCO) Action Statement for preplanned activities.

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

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

e. Provisions for considering other applicable risk-significant contributors such as Level 2 issues 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 implement Section a(3) of the Maintenance Rule with respect to on-line maintenance for risk-informed TS (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 PSA in addition to all SSCs considered high safety significant per Revision 2 of RG 1.160.

The On-Line Risk Monitor (OLRM) will be the primary tool used for risk assessments in support of the CRMP. The existing OLRM uses the Electric Power Research Institute EOOS software and is PSA-informed. The scope of the OLRM will be modified to ensure that all SSCs modeled in the PSA, as well as high safety signiTicant SSCs per Revision 2 of 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 addressed qualitatively. In addition, procedures applicable to the RRAG will ensure that all SSCs included in the PSA model, as well as all high safety significant SSCs not in the PSA, are considered 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 in support of the CRMP. If the OLRM identifies a proposed maintenance activity as potentially 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>y 1

~ St. Lucie Unit1 and Unit2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 16 of 19 LPSI S stem Risk Informed AOT Extension SSCs but not all SSCs modeled in the PSA. FPL will not use the PREMRA matrices for SSCs with risk-informed AOTs, and plans to remove components affected by any such TS changes from the matrices.

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

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

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

Work Control and Operations Procedures will be revised to ensure that if a component within 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 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after the component was removed from service. Although it is expected that on-shift personnel could perform most assessments, 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is a reasonable time frame to ensure adequate resources are on site to perform an assessment and is in line with the existing Condition Report (CR) process used in the plant corrective actions program. The risk 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, will be performed in a time frame defined by the plant's Corrective Action Program (Criteria XVIof Appendix B to 10 CFR Part 50).

Work Control and Operations Procedures will be revised to ensure that if a component within the scope of the CRMP is out of service and additional applicable SSCs become inoperable or non-functional, a risk assessment will be performed as soon as practicable, but no later than 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after the additional SSCs were removed from service. Although it is expected that on-shift personnel could perform most assessments, 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months is a reasonable time frame to ensure adequate resources are on site to perform the assessment and is in line with the existing CR process. The risk assessment would be performed using the OLRM or by the engineering RRAG.

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

As discussed above, risk assessments will be required for both pre-planned and emergent activities within the scope of the CRMP. Based on previous maintenance related risk evaluations and calculations performed in support of PREMRA matrices, FPL has not identified any additional constraints or compensatory actions that should be included with

. St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 17 of 19 LPSI S stem Risk Informed AOT Extension

.the proposed AOT extension in order to avoid or reduce the probability of planned high risk configurations. Assessments performed in accordance with provisions of the CRMP will ensure potentially risk significant configurations are identified prior to removing a component within the scope of CRMP from service for pre-planned maintenance.

Similarly, implementation of the CRMP will ensure that the risk significance of unexpected configurations 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 be dispositioned byimplementing PSA model changes or by the qualitative assessment of the impact of fhe changes on the CRMP assessment fool. This qualitative assessment recognizes thaf changes to fhe PSA fake time fo implement and that changes can be effectivel compensated for without compromising the abilify to make sound engineering judgments.

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

b. Limitations of fhe CRMP assessment tool are identified and understood for each specific AOT extension.

Any specific limitations of the OLRM applicable to CRMP requirements will be identified and understood as part of updating the OLRM to support the CRMP. Any interim limitations of the OLRM due to PSA changes will be brought to the attention of the Work Control and Operations Departments, and specific evaluations will be performed by the engineering RRAG in support of the CRMP until the OLRM can be updated to address the identified limitations.

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

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

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

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

~ St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 18 of 19 LPSI S stem Risk Informed AOT Extension The OLRM is PSA-informed and will be the primary tool used for risk assessments in support of the CRMP. The PSA model is re-quantified for the plant configuration of concern and therefore quantitative results are provided for sound decision-making.

Qualitative input is provided for those components within the scope of the CRMP but outside the scope of the PSA model. FPL will not use the PREMRA matrices for SSCs with risk-informed AOTs, and is planning to remove components affected by any such TS changes from the matrices.

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

Prior to implementing the CRMP, Work Control, Operations, and Reliability and Risk Assessment Group Procedures will contain provisions for performing qualitative risk assessments as required.

3.2.4.5 Ke Com onent 4 Level 2 Issues and External Events: Exfemal events and Level 2 issues 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 events can not be readily performed. A checklist of qualitative considerations will be developed and used when performing risk assessments with the OLRM and by the engineering RRAG.

b. For Level 2 (Containment), the potential risk impact on the large early release frequency is estimated as part of the OLRM results, and acceptance criteria are provided.

In addition, Reliability and Risk Assessment Group Procedures address consideration of the 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 AOT does nof degrade operational safety over time, the licensee should ensun., as part ofifs Maintenance Rule Program (10 CFR 50.65), that when equipmenf does nof meef ifs performance criferia, the evaluation required under fhe Maintenance Rule includes prior related TS changes in ifs scope. If the licensee concludes fhaf the performance or condition of TS equipmenf affected by a TS change does nof meef established performance criferia, appropriafe conecfIve action should be faken in accordance wifh the Mainfenance Rule. Such conecfI've acfI'on could include consideration of another TS change fo shorten the revised AOT, or imposition of a 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) that ensures 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 review of prior risk-informed TS changes as part of the corrective actions for components that do not meet established performance criteria. This requirement will apply to components within the scope of the CRMP, i.e., components for which a risk-informed TS change has been granted.

~ St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 1 Proposed License Amendments Page 19 of 19 LPSI S stem Risk Informed AOT Extension G.2.5 Other Considerations The proposed changes to TS 3.5.2 Action a. are similar to the Combustion Engineering Standard TS approved for licensees for whom the risk-informed LPSI AOT has been granted, and differences are primarily those of structure in order to ensure the proposed action statements remain consistent with the existing St. Lucie TS narrative format.

The editorial changes proposed for the Recirculation Actuation Signal verification test on TS pages 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 proposed changes 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 a facility component located within the restricted area as defined in 10 CFR Part 20. The proposed amendment involves no significant increase in the amounts and no significant change in the types of any eNuents that may be released offsite, and no significant increase in individual or cumulative occupational radiation exposure. FPL has concluded that the proposed amendment involves no significant hazards consideration and meets the criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) and that, pursuant to 10 CFR 51.22(b), an environmental impact statement or environmental 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 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days have been quantitatively evaluated using the current plant specific Probabilistic Safety Assessment for PSL1 and PSL2. The analyses, in conjunction with CE NPSD-995, show that the small increase in the calculated "at power risk" can be offset by averting the risk associated with an unnecessary plant transition to a shutdown mode, and/or reduced risk during shutdown operations that can result from improved flexibility in scheduling and performing surveillance and maintenance 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 Risk Based Analyses of Technical Specifications, December 1994, and, except for the location of the CRMP description, USNRC Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, August 1998. Relative to the average Core Damage Frequency calculated for the appropriate severe accidents, NUREG/CR-6141 states, "A risk-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 the proposed amendment is acceptable.

St. Lucie Unit 1 and Unit 2 Docket Nos. 50-335 and 50-389 Proposed License Amendments LPSI S stem Risk Informed AOT Extension L-99-079 ATTACHMENT2 DETERMINATIONOF NO SIGNIFICANT HAZARDS CONSIDERATION

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St. Lucie Unit 1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 2 Pro'posed License Amendments Page 1 of2 LPSI S stem Risk Informed AOT Extension DETERMINATIONOF NO SIGNIFICANT HAZARDS CONSIDERATION Description of amendment request: The proposed amendments will revise TS 3.5.2, ECCS Subsystems Tavg t 325'F, for both St. Lucie units, to extend the existing 72-hour action completion/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 the specified Recirculation Actuation Signal (RAS) verification test are also included to ensure the terminology used in the specification is consistent with plant design.

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

(1) Operation of the facility in accordance with the proposed amendment would not involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed amendments for St. Lucie Unit 1 and Unit 2 will extend the action completion/allowed outage time (AOT) for a single inoperable Low Pressure Safety Injection (LPSI) train from 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months to 7 days. A LPSI train is designed as a part of each Emergency Core Cooling System (ECCS) subsystem to supplement Safety Injection Tank (SIT) inventory during the early stages of mitigating a Design Basis Accident. As such, components of the LPSI system are not accident initiators, and an extended AOT to restore operability of an inoperable LPSI train would not increase the probability of occurrence of accidents previously analyzed.

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

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

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

St. Lucie Unit1 and Unit 2 L-99-079 Docket Nos. 50-335 and 50-389 Attachment 2 Proposed License Amendments Page 2 of2 LPSI S stem Risk Informed AOT Extension Therefore, operation of either facility in accordance with its proposed amendment would not involve a 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 create the 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 operation defined in either Facility License. The changes do not involve the addition or modification of equipment nor do they alter the design of plant systems. Therefore, operation of either facility in accordance with its proposed amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated.

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

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

Based on the above discussion and the supporting Evaluation of Proposed Technical Specification Changes, FPL has determined that the proposed license amendments involve no significant hazards consideration.

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