SBK-L-05260, License Amendment Request 05-11, Changes to Technical Specification 3.8.3.1, Onsite Power Distribution, for Vital Inverter Allowed Outage Time.

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License Amendment Request 05-11, Changes to Technical Specification 3.8.3.1, Onsite Power Distribution, for Vital Inverter Allowed Outage Time.
ML053420341
Person / Time
Site: Seabrook NextEra Energy icon.png
Issue date: 12/06/2005
From: St.Pierre G
Florida Power & Light Energy Seabrook
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-05260
Download: ML053420341 (21)
v • d • e


Text

FPL Energy Seabrook Station FPL Energy P.O. Box 300 Seabrook, NH 03874 Seabrook Station (603) 773-7000 December 6, 2005 SBK-L-05260 Docket No. 50-443 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Seabrook Station License Amendment Request 05-11 "Changes to Technical Specification 3.8.3.1, Onsite Power Distribution, for Vital Inverter Allowed Outage Time" FPL Energy Seabrook, LLC (FPL Energy Seabrook) has enclosed herein License Amendment Request (LAR) 05-11. License Amendment Request 05-11 is submitted pursuant to the requirements of 10 CFR 50.90 and 10 CFR 50.4.

This proposed amendment will revise Seabrook Station Technical Specification (TS) 3.8.3.1 "Onsite Power Distribution," to extend the allowed outage time for the two balance-of plant (BOP) vital inverters from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days. Extending the AOT would provide the time necessary to perform repairs and post-maintenance testing in the event an inverter becomes inoperable. The benefit of the extended AOT includes minimizing the potential safety consequences and operational risks associated with the transient of a plant shutdown due to an inoperable inverter that cannot be repaired within the current 24-hour AOT. In addition, an AOT extension would avoid the need for a Notice of Enforcement Discretion (NOED). On November 30, 2005, FPL Energy Seabrook requested and received approval of a NOED for an 18-hour extension to the 24-hour AOT for an inoperable inverter. This LAR is in follow-up to the NOED.

This Technical Specification change has been prepared in accordance with the guidance provided in Regulatory Guide 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk Informed Decisions on Plant-Specific Changes to the Licensing Basis" and Regulatory Guide 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking; Technical Specifications." The evaluation of this change concludes that the requested AOT extension is acceptable and results in a minimal increase in risk.

an FPL Group company

U. S. Nuclear Regulatory Commission SBK-L-05260 l Page 2 As discussed in the enclosed LAR, the proposed change does not involve a significant hazard consideration pursuant to 10 CFR 50.92. A copy of this letter and the enclosed LAR has been forwarded to the New Hampshire State Liaison Officer pursuant to 10 CFR 50.91(b). FPL Energy Seabrook has determined that LAR 05-11 meets the criteria of 10 CFR 51.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact Statement. The Station Operation Review Committee and the Company Nuclear Review Board have reviewed this LAR.

FPL Energy Seabrook requests NRC Staff review and approval of LAR 05-11 with issuance of a license amendment by December 6, 2006 and implementation of the amendment within 90 days.

Should you have any questions regarding this letter, please contact Mr. James M. Peschel, Regulatory Programs Manager, at (603) 773-7194.

Very truly yours, FPL Energy Seabrook, LLC.

Gene F. St. Pierre Site Vice President

Enclosures:

Notarized Affidavit Licensee's Evaluation of the Proposed Change Attachments:

1. Proposed Technical Specification Change (mark-up)
2. Proposed Technical Specification page (re-type) cc: S. J. Collins, NRC Region I Administrator G. E. Miller, NRC Project Manager, Project Directorate I-2 G.T. Dentel, NRC Senior Resident Inspector Mr. Bruce G. Cheney, ENP, Director, Division of Emergency Services N.H. Department of Safety Division of Emergency Services, Communications, and Management Bureau of Emergency Management 33 Hazen Drive Concord, NH 03305

FPL Energy Seabrook Station The following information is enclosed in support of this License Amendment Request:

  • Enclosure - Licensee's Evaluation of the Proposed Change
  • Attachment 1 - Proposed Technical Specification Change (mark-up)
  • Attachment 2 - Proposed Technical Specification Page (re-type)

I, Gene St. Pierre, Site Vice President of FPL Energy Seabrook, LLC hereby affirm that the information and statements contained within this License Amendment Request are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

Sworn and Subscribed before me this

( day of Axe , 2005

,4/4e 'or14

-- Gene St. Pierre w- iSite Vice President

., X - .- .

I II'l . . .

,

  • en, I r - 'T n e

Enclosure Licensee's Evaluation of the Proposed Change

LICENSEE'S EVALUATION

Subject:

License Amendment Request 05-11, Changes to Technical Specification 3.8.3.1, "Onsite Power Distribution," for Vital Inverter Allowed Outage Time DESCRIPTION PROPOSED CHANGE BACKGROUND TECHNICAL ANALYSIS REGULATORY ANALYSIS 5.1 No Significant Hazards Consideration 5.2 Applicable Regulatory Requirements / Criteria

6. ENVIRONMENTAL CONSIDERATION
7. REFERENCES 1

1.0 DESCRIPTION

This proposed amendment will revise Seabrook Station Technical Specification (TS) 3.8.3.1 "Onsite Power Distribution," to extend the allowed outage time (AOT) for the two balance-of-plant (BOP) vital instrument bus inverters from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days.

Extending the AOT will provide the time necessary to perform repairs and post-maintenance testing in the event an inverter becomes inoperable. The benefit of the extended AOT includes minimizing the potential safety consequences and operational risks associated with the transient of a plant shutdown due to an inoperable instrument bus inverter that cannot be repaired within the current 24-hour AOT. In addition, an AOT extension will avoid the need for a Notice of Enforcement Discretion (NOED). On November 30, 2005, FPL Energy Seabrook requested and received approval of a NOED (Reference 1) for an 18-hour extension to the 24-hour AOT for an inoperable instrument bus inverter. This LAR is in follow-up to the NOED.

2.0 PROPOSED CHANGE

Currently, the TS specify a 24-hour AOT with any one of the six vital instrument bus inverters inoperable. This proposed change extends the AOT for the two BOP vital inverters, 1-EDE-I-IE and 1-EDE-I-1F, to 7 days.

With one A.C. vital panel either not energized from its associated inverter, or with the inverter not connected to its associated D.C. bus: reenergize the A.C. vital panel within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />; and

1. For A.C. Vital Panels IA, IB, IC, and ID, reenergize the A.C. vital panel from its associated inverter connected to its associated D.C. bus within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
2. For A.C. Vital Panels IE and IF, reenergize the A.C. vital panel from its associated inverter connected to its associated D.C. bus within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

3.0 BACKGROUND

Descriptionof the 120 Volt A. C. ElectricalSystem The 120 volt AC vital instrument power system ensures that sufficient power will be available to supply the safety-related equipment required for (1) safe shutdown of the plant, and (2) the mitigation of accident conditions for any Condition I through IV event.

The minimum specified independent and redundant AC and DC power sources and distribution systems satisfy the requirements of General Design Criterion 17 of Appendix A to 10 CFR Part 50.

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The 120 volt AC instrument power system is comprised of six independent AC buses designated as 1A through IF, with each bus having its own uninterruptible power supply (UPS). The six vital UPS units are normally powered from the 480V system and can also convert 125-volt DC power from station batteries to 120-volt AC power. This system provides the source of power for reactor protection, reactor control, and BOP instrument systems. The UPS units' primary function is to continuously supply power to critical safety-related loads that cannot tolerate momentary power interruptions under normal, transient, and accident operating conditions. Each vital UPS and its supporting components are classified as ANS Safety Class 3, Seismic Category I, and Electrical Class 1E per IEEE 308 and Regulatory Guide 1.32.

The UPSs (vital instrument bus inverters I-EDE-I-IE and I-EDE-I-IF) associated with instrument buses IE and IF supply power to the BOP vital instrumentation. UPS IE is "A" train and UPS IF is "B" train. Accordingly, the UPS units derive their AC and DC input power from train "A" and train "B" safety-related power supplies. Each of the two BOP vital instrument buses is provided with a static transfer switch for automatic, fast transfer of these buses to a maintenance supply from a 480/120-volt AC transformer connected to a non-safety-related power source (with a back up power supply from the emergency diesel generator) in the event of unavailability of the associated UPS. In addition to the automatic transfer switch, manual transfer capability to maintenance supply is also provided to bypass and isolate the static transfer switch for maintenance.

On each UPS, instrumentation is provided to monitor AC and DC input currents, as well as output current and voltage. Alarms are provided on the station computer for loss of AC voltage on the vital instrument bus.

Basesfor Requesting the Proposed Change On November 30, 2005 FPL Energy Seabrook received approval of enforcement discretion for an 18-hour extension to the AOT for an inoperable vital instrument bus inverter. The need for the request followed a failure of vital inverter IF due to a malfunction of a circuit board. The 24-hour AOT did not provide adequate time to troubleshoot the problem, complete the repair activities, and perform post-maintenance testing to return the inverter to operable status. This license amendment request is the result of a commitment that accompanied the November 30, 2005 notice of enforcement discretion (NOED).

The 24-hour AOT for an inoperable instrument bus inverter creates an unnecessary burden. Performing an on-line repair of a failed inverter will likely exceed the AOT. In addition to the recent NOED approved for FPL Energy Seabr ok, both Nine Mile Point and Watts Bar nuclear stations received enforcement discretion m 2003 and 2001, respectively, to extend the AOT for an inoperable instrument lus inverter (References 2 and 3). Extending the AOT to seven days for an inoperabl instrument bus inverter will:

  • Reduce the potential for a transient due to an unplanned shutdown to repair a failed inverter.
  • Provide additional time to complete repairs following an inverter malfunction.

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  • Increase the time to perform troubleshooting, repair, and testing following inverter equipment problems, which will enhance the safety and reliability of equipment and personnel.
  • Allow time to perform routine maintenance activities on the vital inverters in Modes 1 through 4. Performing preventative maintenance while on-line will enhance the ability to focus quality resources on the activity and will improve the availability of the inverters during refueling outage periods.

Precedent exists for extending the AOT for an inoperable instrument bus inverter to 7 days. In November 2003, the NRC issued Amendment No. 135 and No. 129 to Byron and Braidwood Stations, respectively (Reference 4). These amendments revised the TS to permit a 7-day completion time (AOT) for an inoperable vital instrument bus inverter.

Similarly, North Anna received approval of a 7-day AOT for vital instrument bus inverters in Amendment No. 217 in May 2004 (Reference 5). The change proposed in this LAR is similar to those previously approved; however, FPL Energy Seabrook is only requesting the extended AOT for the two vital instrument bus inverters that power the BOP instrument buses whereas the Byron, Braidwood, and North Anna amendments applied the AOT extensions to the inverters associated with the instrument buses that power the reactor protection system (RPS).

4.0 TECHNICAL ANALYSIS

Evaluation of Risk Impact Purpose This evaluation considers the increased risk from an extension of the AOT for instrument bus inverters l-EDE-I-1-E and 1-EDE-I-I-F from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days. The subject inverters, while safety related, do not solely support any risk significant functions. Failure of the inverter(s) does not create an initiating event or increase the frequency of an initiating event. The current 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed outage time (AOT) is overly conservative and, since exceeding the AOT requires a plant shutdown, has a negative impact on overall plant risk.

Evaluation This evaluation is a risk assessment for extending the AOT from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days. RG 1.177 recognizes that the scope and level of detail of a risk evaluation for a TS change depends upon the particular systems and functions affected, and in some instances, a qualitative rather than quantitative analysis is acceptable. Consistent withis consideration, this is generally a qualitative evaluation since the inverters in question are not modeled in the Seabrook Station PRA model because they do not perform mitigative functions. The PRA model is an all-modes, full scope, level 3 PRA. The PRA model was peer reviewed according to the Westinghouse Owner's Group process in 1999.

There are five open 'B' level comments (level 2 success criteria) that will be closed by December 31, 2005 (Reference 6). None of these comments affect the conclusions of this 4

evaluation. In addition, the current PRA model had a limited scope peer review (SC:

success criteria, AS: accident sequence analysis, HR: human reliability analysis, and configuration control) in accordance with the ASME standard and Regulatory Guide 1.200. Open comments from this review are expected to close by December 31, 2005.

There were no items from that review that impact the conclusions of this analysis.

The inverters are not modeled because they do not solely support any mitigative functions (e.g. primarily indication or limited automatic operations that have reliable manual backup from the main control board) and failure of these inverters does not create an initiating event. Failure of these inverters does not affect containment function or increase the likelihood of a containment bypass event. These inverters do not supply power to the reactor protection system (RPS). Seabrook Station operating experience demonstrates that failure of these inverters does not result in a plant transient.

Upon inverter failure, there is an automatic transfer to a maintenance power supply. This maintenance supply is diesel backed, so inverter failure only represents a marginal loss of redundant supply (i.e. DC power input) to the associated loads, but does not fail any equipment. The maintenance supplies (1-EDE-MCC-53 1, 1-EDE-MCC-63 1) for both of the subject inverters are included in the PRA model.

The probability of inverter failure during operation (i.e. one year) is approximately 1.58E-01. The failure probability of the maintenance power supply during a 7-day period is approximately 1.4E-04. The conditional probability of inverter failure followed by subsequent maintenance power supply failure in the next 7 days is approximately 2.2E-05. This is a small probability and is roughly equivalent to the probability of a medium LOCA during a calendar year.

Multiple failures need to occur before the failure of an inverter would result in consequences. For example, the combined failure of one of the subject inverters and the associated maintenance power supply would be loss of the ability to remotely start the ventilation fans for the associated emergency diesel generator. In this case, the fans could be started by manual actuation of the starting relays. In addition, the associated emergency diesel would not be required unless there was a concurrent loss of offsite power (LOOP). The conditional probability of the three events (inverter failure, maintenance supply failure, LOOP) is approximately 1.1E-8. Failure of the subject inverter(s) and subsequent failure of the maintenance power supply would not affect the ability of the Supplemental Emergency Power System (SEPS) to provide power to the associated emergency bus.

These inverters are of a different design and manufacturer tha ithe inverters that supply RPS so there are no common cause considerations for the more risk-sigiAficant inverters (1A, lB, IC, ID).

Removal of an inverter from service is subject to the configuration risk management requirements of 10CFR50.65(a)(4).

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Safety Significance Extending the AOT for instrument bus inverters l-EDE-I-I-E and I-EDE-I-I-F from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days does not increase the risk of core damage or a large early release. Failure of these inverters does not adversely affect any mitigating equipment or create an initiating event.

Conclusion This evaluation supports an AOT extension for inverter l-EDE-I-lE and l-EDE-I-lF from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days. There is no increase in core damage frequency or large early release frequency as a result of failure of inverter 1-EDE-I-l-E or 1-EDE-I-1-F. Failure of these inverters does not create an initiating event or increase the likelihood of an initiating event.

Deterministic Evaluation Defense in Depth Assessment The proposed AOT extension will be applied to the two vital instrument bus inverters that power the BOP instrumentation. The AOT for the four vital instrument bus inverters that provide power to the Reactor Protection and Engineered Safety Features Actuation systems will remain unchanged at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

During operation with an inoperable, out-of-service vital instrument bus inverter, the associated BOP instrument bus is energized from its maintenance source through a safety-related static transfer switch. The source of power for the maintenance supply is a non-safety-related motor control center (MCC), which relies on the EDG as the back up power supply. In the event of a failure of vital inverter IE or IF, the static transfer switch will shift the instrument bus to its maintenance source with no interruption of power to the instrument bus. Should a loss of off-site power (LOOP) occur while an instrument bus is aligned to its maintenance source, the instrument bus will remain de-energized for approximately 10 seconds until the EDG starts and energizes the maintenance supply. In order for the instrument bus to remain de-energized, the EDG would have to fail or the MCC that provides the maintenance power source would have to fail to energize.

However, the TS will continue to permit no more than one vital instrument bus inverter to be inoperable, so that when one vital instrument bus is aligned to its maintenance source, the redundant instrument bus inverters will be operable and aligned to a DC power supply.

ConfigurationRisk Management Prior to performing maintenance activities during plant operation, on-line maintenance reviews evaluate the risk impact of the planned work. The weekly schedule of planned work receives a risk assessment review as required by 10 CFR 50.65 (a)(4).

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Additionally, the work control process provides for prompt assessment of risk when emergent conditions arise during plant operation. FPL Energy Seabrook administrative procedures implement a "protected train" concept that serves to maintain the availability and operability of redundant systems and components. Equipment in the protected train that is required for reactor safety must be either operating or operable and, therefore, may not be removed from service for maintenance or surveillance testing. The station does not schedule maintenance activities that are likely to result in exceeding a TS AOT. For activities that are likely to exceed 50% of the AOT, compensatory measures and contingency plans are considered to reduce risk and equipment unavailability, and to enhance reliability and margin of safety.

MaintenanceRule (MR) and Implementation and MonitoringProgram The Maintenance Rule, 10 CFR 50.65(a)(4), requires assessments before conducting maintenance activities on structures, systems, and components (SSCs) that are covered by the Maintenance Rule, and management of any increase in risk that may result from the proposed activities. RG 1.174, Section 2.3, Element 3, "Define Implementation and Monitoring Program," states that monitoring that is in conformance with the Maintenance Rule can be used to satisfy Element 3 when the monitoring performed under the Maintenance Rule is sufficient for the SSCs affected by the risk-informed application.

The reliability of the instrument bus inverters is monitored under the MR program. If pre-established reliability criteria are exceeded, the components are evaluated in accordance with 10 CFR 50.65(a)(1), with increased management attention and goal setting in order to restore performance to acceptable levels. The inverters are all currently meeting established performance criteria and are in the 10 CFR 50.65(a)(2) category.

To ensure that the extended instrument bus inverter AOT does not degrade operational safety over time, an evaluation is required, as part of the MR program, if equipment does not meet its performance criteria. Appropriate corrective action will be taken as required by the MR.

Safety MarginAssessment The instrument bus inverters are the preferred source of power for the AC instrument buses because of the stability and reliability that they provide. The inverters can be powered from an AC source or from an associated 125-volt DC battery. The battery provides an uninterruptible power source. Each BOP instrument bus inverter is equipped with a safety-related static transfer switch that connects the vital inverter output to its associated instrument bus. The static transfer switch will transfer the instrument bus power source to its maintenance supply in the absence of an output from the inverter, in the event of an overload condition, or with a degraded AC power source to the inverter.

The static transfer switch is an electronic, solid state device that will automatically or manually transfer instrument bus power from the inverter to the maintenance source, or from the maintenance source to the inverter, without interruption of power.

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In the event of a loss of off-site power (LOOP) with a BOP vital instrument bus aligned to its maintenance source, the instrument bus will remain de-energized for approximately 10 seconds until the EDG starts and energizes the maintenance supply. In order for the instrument bus to remain de-energized, the EDG would have to fail or the MCC that provides the maintenance power source would have to fail to energize. The simultaneous failure of an inverter and its maintenance supply coincident with a LOOP is unlikely.

Further, in the event of a LOOP, the supplemental emergency power system (SEPS) could energize the affected emergency bus. Nonetheless, a failure to energize a BOP instrument bus following a LOOP has no impact on the ability of the RPS or ESF systems to actuate.

5.0 REGULATORY SAFETY ANALYSIS 5.1 No Significant Hazards Consideration In accordance with 10 CFR 50.92, FPL Energy Seabrook has concluded that the proposed changes do not involve a significant hazards consideration (SHC). The basis for the conclusion that the proposed changes do not involve a SHC is as follows:

1. The proposed changes do not involve a significant increase in the probability or consequences of an accidentpreviously evaluated.

The proposed change extends the allowed outage time (AOT) for the balance-of-plant (BOP) instrument bus inverters from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to seven days. The BOP instrument bus inverters do not solely support any risk-significant functions. The failure of an inverter is not an initiator of any analyzed event and does not increase the frequency of an initiating event. Consequently, extending the AOT will not have an impact on the frequency of occurrence of any event previously analyzed. The proposed change does not alter the design, configuration, operation, or function of any plant system, structure, or component. As a result, the outcomes of previously evaluated accidents are unaffected. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. The proposedchanges do not create the possibility of a new or different kind of accidentfrom anypreviously evaluated.

No new accident scenarios, failure mechanisms, or limiting single failures are introduced as a result of the proposed change. The proposed change does not challenge the performance or integrity of any safety-related system. The proposed change neither installs nor removes any plant equipment, nor alters the design, physical configuration, or mode of operation of any plant structure, system, or component. Installed equipment will not be operated in a new or different manner.

No physical changes are being made to the plant, so no new accident causal mechanisms are being introduced. Procedures that ensure the unit operates within analyzed limits and procedures that respond to off-normal and emergency conditions 8

are not altered with this proposed change. Therefore, the proposed change does not create the possibility of a new or different accident from any previously evaluated.

3. The proposedchanges do not involve a sign ificant reduction in the margin of safety.

The margin of safety associated with the acceptance criteria of any accident is unchanged. The proposed change does not alter the design, configuration, operation, or function of any plant system, structure, or component. The ability of any operable structure, system, or component to perform its designated safety function is unaffected by this change. Operation with one instrument bus inverter inoperable and the associated instrument bus aligned to its maintenance supply does not result in a significant reduction in the margin of safety. Surveillance testing of the emergency diesel generators (EDGs) and the electrical distribution system provides confidence that the EDGs will energize the emergency AC buses following a loss of power.

Therefore, the proposed change does not involve a significant reduction in the margin of safety.

Based on the above, FPL Energy Seabrook concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92 (c), and accordingly, a finding of"no significant hazards consideration" is justified.

5.2 Applicable Regulatory Requirements / Criteria 5.2.1 Regulations General Design Criterion (GDC) 17, "Electric power systems," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50 requires, in part, that nuclear power plants have onsite and offsite electric power systems to permit the functioning of SSCs that are important to safety. The onsite power system is required to have sufficient independence, redundancy, and testability to perform its safety function, assuming a single failure. The proposed change continues to provide sufficient independence, redundancy, and testability and therefore continues to meet GDC- 17.

GDC- 18, "Inspection and testing of electric power systems," requires that electric power systems that are important to safety must be designed to permit appropriate periodic inspection and testing. The proposed change does not make changes to inverter inspections or testing and therefore continues to meet GDC-1 8.

5.2.2 Design Bases - UFSAR The onsite AC power system is designed to permit the functioning of structures, systems, and components important to safety under all normal and accident conditions. The system provides sufficient capacity and capability to assure that specified fuel design limits and design conditions of the reactor pressure boundary 9

core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents.

The onsite AC system has sufficient independence, redundancy, and testability to perform its safety functions assuming a single failure. Independence is provided by physical separation of components and cables to reduce vulnerability of redundant engineered safety features systems to single credible accidents.

Systems and components which comprise the onsite AC distribution system have been designed to afford maximum in-service testability. Where in-service testability cannot be provided due to adverse impact on plant operation, systems and components are tested during plant shutdown.

5.2.3 Analysis The proposed 7 day AOT for the BOP instrument bus inverters was evaluated using a deterministic evaluation and a qualitative risk assessment. The deterministic evaluation considered the attributes contained in RG 1.177, "An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications," and concluded that the defense in depth philosophy and sufficient safety margins are maintained. Implementation of the Maintenance Rule in accordance with 10CFR50.65 manages plant risk for both planned maintenance activities and for emergent conditions. Instrument bus inverter reliability will continue to be monitored and assessed under the Maintenance Rule. The risk assessment found that the proposed change does not increase the risk of core damage or a large early release frequency. The instrument bus inverters involved in this proposed change do not supply any risk significant loads.

5.2.3 Conclusion FPL Energy has concluded that reasonable assurance exists that the proposed change (1) will not endanger the health and safety of the public, and (2) is in compliance with NRC regulations.

6.0 ENVIRONMENTAL CONSIDERATION

The proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant icrease in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22 (c) (9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement of environmental assessment need be prepared in connection with the proposed amendment.

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7.0 REFERENCES

1. FPL Energy Seabrook Letter SBK-05258, Request for Notice of Enforcement Discretion.

December 1, 2005.

2. Notice of Enforcement Discretion Regarding Nine Mile Point Unit 2 [TAC No. MC0294, NOED No. 2003-03-01-002], August 18, 2003.
3. Notice of Enforcement Discretion for Tennessee Valley Authority Regarding Watts Bar Nuclear Plant Unit 1, NOED No. 2001-2-001, March 8, 2001.
4. Amendment No. 135 to NPF-37 (Byron 1)

Amendment No. 135 to NPF 66 (Byron 2)

Amendment No. 129 to NPF-72 (Braidwood 1)

Amendment No. 129 to NPF-77 (Braidwood 2)

5. Amendment No. 235 to NPF-4 (North Anna 1)

Amendment No. 217 to NPF-7 (North Anna 2)

6. SSPSS-2004, "Seabrook Station Probabilistic Safety Study, 2004 Update," December 2004.

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Attachment 1 Proposed Technical Specification Change (mark-up)

Refer to the attached markup of the proposed change to the Technical Specifications. The attached markup reflects the currently issued version of the Technical Specifications. At the time of submittal, the Technical Specifications were revised through Amendment No. 104. Pending Technical Specifications or Technical Specification changes issued subsequent to this submittal are not reflected in the enclosed markup.

Listed below are the license amendment requests that are awaiting NRC approval and may impact the currently issued version of the Technical Specifications.

LAR Title FPL Energy Seabrook Date of SBK Letter No. Submittal NONE The following Technical Specifications are included in the attached markup:

Technical Specification Title Page 3.8.3.1 Onsite Power Distribution Operating 3/4 8-17 3/4 8-17a X,:.

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ELECTRICAL POWER SYSTEMS ONSITE POWER DISTRIBUTION OPERATING LIMITING CONDITION FOR OPERATION 3.8.3.1 (Continued)

i. Train A, 125-volt D.C. Busses consisting of:
1) 125-volt D.C. Bus #11A energized from Battery Bank 1A* or 1C*, and
2) 125-volt D.C. Bus #11 C energized from Battery Bank 1C* or 1A*.
j. Train B, 125-volt D.C. Busses consisting of:
1) 125-volt D.C. Bus #11 B energized from Battery Bank 1B* or 1D*, and
2) 125-volt D.C. Bus #11 D energized from Battery Bank 1D* or 1B*.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTION:

a. With one of the required trains of A.C. emergency busses (except 480-volt Emergency Bus # E64) not fully energized, reenergize the train within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
1. With 480-volt Emergency bus #E64 not fully erergized, reenergize the bus within 7 days or be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD j1 SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. ,
b. With one A.C. vital panel either not energized from its associated inverter, or with the inverter not connected to its associated D.C. bus: 4reenergize the I A.C. vital panel within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT STANDBY within the next Ar e j-.k 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />; andI2T
  • V Ad reenergize the A.C. vital panel from itsX associated inverter connected to its I . 61 pa S t ,/ V associated D.C. bus within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be' in at least HOT STANDBY within I C, and Cbgo the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
c. With one D.C. bus not energized from its associated battery bank, reenergize the D.C. bus from its associated battery bank or close the bus tie to the alternate OPERABLE battery of the same train within 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s* or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

SEABROOK - UNIT 1 3/4 8-17 Amendment No. 4t,)

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Attachment 2 Protosed Technical Specification Page (re-tvpe)

Refer to the attached retype of the proposed change to the Technical Specifications. The attached retype reflects the revised, currently issued version of the Technical Specifications. At the time of submittal, the Technical Specifications were revised through Amendment No. 104.

Pending Technical Specifications or Technical Specification changes issued subsequent to this submittal are not reflected in the enclosed retype.

Listed below are the license amendment requests that are awaiting NRC approval and may impact the currently issued version of the Technical Specifications.

LAR Title FPL Energy Seabrook Date of SBK Letter No. Submittal NONE The following revised Technical Specifications are included in the attached retype:

Technical Specification Title 3.8.3.1 Onsite Power Distribution Operating 3/4 8-17 3/4 8-17a

ELECTRICAL POWER SYSTEMS ONSITE POWER DISTRIBUTION OPERATING LIMITING CONDITION FOR OPERATION 3.8.3.1 (Continued)

i. Train A, 125-volt D.C. Busses consisting of:
1) 125-volt D.C. Bus #11A energized from Battery Bank 1A* or lC*, and
2) 125-volt D.C. Bus #11 C energized from Battery Bank 1C* or 1A*.
j. Train B, 125-volt D.C. Busses consisting of:
1) 125-volt D.C. Bus #11 B energized from Battery Bank 1B* or 1D*, and
2) 125-volt D.C. Bus #11 D energized from Battery Bank 1D* or 1B*.

APPLICABILITY: MODES 1, 2,3, and 4.

ACTION:

a. With one of the required trains of A.C. emergency busses (except 480-volt Emergency Bus # E64) not fully energized, reenergize the train within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
1. With 480-volt Emergency bus #E64 not fully energized, reenergize the bus within 7 days or be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
b. With one A.C. vital panel either not energized from its associated inverter, or with the inverter not connected to its associated D.C. bus: reenergize the A.C.

vital panel within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />; and

1. For A.C. Vital Panels 1A, 1B, 1C, and 1D, reenergize the A.C. vital panel from its associated inverter connected to its associated D.C. bus within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
2. For A.C. Vital Panels 1E and I F, reenergize the A.C. vital panel from its associated inverter connected to its associated D.C. bus within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

SEABROOK - UNIT 1 3/4 8-17 Amendment No. 48,

ELECTRICAL POWER SYSTEMS ONSITE POWER DISTRIBUTION OPERATING LIMITING CONDITION FOR OPERATION 3.8.3.1 (Continued)

c. With one D.C. bus not energized from its associated battery bank, reenergize the D.C. bus from its associated battery bank or close the bus tie to the alternate OPERABLE battery of the same train within 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s* or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

SURVEILLANCE REQUIREMENTS 4.8.3.1 The specified busses and panels shall be determined energized in the required manner at least once per 7 days by verifying correct breaker alignment and indicated voltage on the busses.

  • No more than one Battery Bank (1A, 1B, 1C, or 1D) at a time may be taken out of service for more than 30 days.

SEABROOK - UNIT 1 3/4 8-17a Amendment No. 48,

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