ML040620457

Change to License Amendment Request 03-01, Changes to Electrical Power Systems - A.C. Sources Technical Specifications - Inclusion of the Supplemental Emergency Power System

ML040620457
Person / Time
Site:	Seabrook
Issue date:	02/23/2004
From:	Warner M Florida Power & Light Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NYN-04006
Download: ML040620457 (10)

Text

FPL Energy Seabrook Station FPL Energy P.O. Box 300 Seabrook, NH 03874 Seabrook Station (603) 773-7000 FEB 2 3 2004 Docket No. 50-443 NYN-04006 United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001

Reference:

NYN-03069, "License Amendment Request 03-01, Changes to Electrical Power Systems - A.C. Sources Technical Specifications -Inclusion of the Supplemental Emergency Power System, dated 8/25/03 Seabrook Station Change to License Amendment Request 03-01, "Changes to Electrical Power Systems - A.C. Sources Technical Specifications -

Inclusion of the Supplemental Emergency Power System" FPL Energy Seabrook, LLC (FPLE Seabrook) has enclosed herein a change to License Amendment Request (LAR) 03-01.

The change to LAR 03-01 is submitted pursuant to the requirements of 10 CFR 50.90 and 10 CFR 50.4.

The proposed changes submitted in LAR 03-01 are based on the permanent installation of a non safety-related supplemental emergency power system (SEPS), currently in the final design and construction phase of the project. At the time LAR 03-01 was submitted, the final vendor had not been chosen. Subsequently, the vendor has been selected and a final detailed design review was performed. The changes to LAR 03-01 are the result of changes made to the final SEPS design. The Technical Specification changes, originally proposed in LAR 03-01, are not affected by the change to LAR 03-01.

The changes to the detailed design do not change the overall scope nor the intent of the SEPS, which is designed to serve as a reliable backup standby AC power supply to either emergency bus whenever one of the emergency diesel generators (EDGs) is out of service. As stated in LAR 03-01, once operational, the SEPS will be capable of supplying the required safety-related and non safety-related safe shutdown loads during a total loss of offsite power (LOOP) event if both emergency diesel generators fail to start and load. Installation of the SEPS is in keeping with FPLE Seabrook and NRC philosophy to provide and ensure defense-in-depth to protect the health and safety of the public.

an FPL Group company

U. S. Nuclear Regulatory Commission NYN-04006/Page 2 The design changes necessitating the change to LAR 03-01 are described herein as well as inclusion of replacement pages containing the corrected information.

The conclusions of the deterministic evaluation and the probabilistic risk assessment (PRA) evaluation presented in LAR 03-01 remain valid, as well as the conclusion that the Technical Specification changes proposed in LAR 03-01 do not involve a significant hazards consideration (SHC) pursuant to 10 CFR 50.92. Additionally, the Technical Specification changes proposed in LAR 03-01 meet the criteria delineated in 10 CFR 51.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact Statement.

A copy of this letter has been forvarded to the New Hampshire State Liaison Officer pursuant to 10 CFR 50.91(b). FPLE Seabrook requests NRC Staff review of LAR 03-01 and this change with issuance of a license amendment by August 27, 2004.

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.

Mark E. Warner Site Vice President cc:

H. J. Miller, NRC Region I Administrator V. Nerses, NRC Project Manager, Project Directorate I-2 G.T. Dentel, NRC Senior Resident Inspector Mr. Bruce Cheney, Director New Hampshire Office of Emergency Management State Office Park South 107 Pleasant Street Concord, NH 03301

U. S. Nuclear Regulatory Commission NYN-04006/Page 3 OATH AND AFFIRMATION I, Mark E. Warner, Site Vice President of FPL Energy Seabrook, LLC, hereby affirm that the information and statements contained within this correction to License Amendment Request 03-01 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

_d3 dayof F4 rravL

, 2004 Mark E. Warner Site Vice President Notary Public

ATTACHMENT I - CHANGE DETAILS The final design of the SEPS equipment has been completed. The proposed design that was used to develop the LAR included a plug arrangement to provide service power to the SEPS equipment. Loss of this power would also be used to initiate the loss of power signal to start the SEPS gensets. The plug would manually be switched from emergency bus E5 to emergency bus E6, as required. Service power would follow the alignment of the SEPS.

Once the vendor was chosen and a detailed design review was performed, it was determined the proposed plug design was not suitable for the application. The proposed plug design would not provide power to the SEPS diesel cooling fan until the SEPS feeder breaker was closed. Based on requirements of the emergency procedures this would not occur until about 30 minutes after the SEPS gensets started.

The final design provides service power from a non-emergency bus. When a loss of offsite power condition occurs a start signal will start the SEPS gensets and an automatic transfer switch will be used to transfer the power supply from the non-emergency bus to the SEPS output to provide power to the cooling fan.

Based on the final design the following corrections are required to the LAR submittal.

The revised pages are included as Attachment 2 with revision bars in the right hand margin annotating the revised wording.

Page 4 Current Wording SEPS Design Description The design of the SEPS will meet the criteria set out below:

The SEPS will automatically start on an undervoltage condition sensed on the emergency bus that it is aligned to.

Page 4 Revised Wording SEPS Design Description The design of the SEPS will meet the criteria set out below:

• The SEPS will automatically start on a loss of power condition.

Page 18 Current Wording SEPS Support The SEPS support system failures are not critical to the success of the SEPS and are not included in the SEPS hardware fault tree. Support system failures are readily apparent and do not represent an immediate loss of function. Support power comes from a transformer fed from either bus E5 or bus E6 that supplies a 480-volt electrical power panel located at the SEPS gensets.

Page 18 Revised Wording SEPS Support The SEPS support system failures are not critical to the success of the SEPS and are not included in the SEPS hardware fault tree. Support system failures are readily apparent and do not represent an immediate loss of function. Support power comes from a non-emergency supply that supplies a 480-volt electrical power panel located at the SEPS gensets.

Page 19 Current Wording Human Reliability In very rare cases an additional operator action is required to realign the SEPS to the opposite train (bus E5). One such case is a failure of bus E6. In addition to the above operator actions, the operator in the switchgear room must obtain tools, procedure and protective gear to rack out the breaker at bus E6 and rack in the breaker at bus E5. The operator must then position the transfer switch to bus E5 and switch the SEPS 480 V support power supply to bus E5 as well.

Page 19 Revised Wording Human Reliability In very rare cases an additional operator action is required to realign the SEPS to the opposite train (bus E5). One such case is a failure of bus E6. In addition to the above operator actions, the operator in the switchgear room must obtain tools, procedure and protective gear to rack out the breaker at bus E6 and rack in the breaker at bus E5. The operator must then position the transfer switch to bus E5.

Technical Requirement 31 Sheet I of 2 Current Wording ACTION: b.3) c) Verifying SEPS 5 kV and 480 V circuit breaker / transfer switch / plug alignment to the selected emergency bus; and SURVEILLANCE REQUIREMENTS

a. At least once every 31 days by:

3) Verifying SEPS 5 kV and 480 V circuit breaker / transfer switch / plug alignment to the selected emergency bus; and Technical Requirement 31 Sheet I of 2 Revised Wording ACTION: b.3) c) Verifying SEPS 5 kV and 480 V circuit breaker and transfer switch alignment to the selected emergency bus; and SURVEILLANCE REQUIREMENTS

a. At least once every 31 days by:

3) Verifying SEPS 5 kV and 480 V circuit breaker and transfer switch alignment to the selected emergency bus; and

ATTACHMENT 2 LAR REPLACEMENT PAGES

emergency bus whenever one of the emergency diesel generators is out of service, particularly during Modes 1 through 4 operation'. The SEPS is verified available and an operational readiness status check is performed when it is anticipated that one of the EDGs will be inoperable for longer than the allowable outage time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The design of the SEPS is capable of providing the required safety-related and non safety-related safe shutdown loads in the event of a total loss of offsite power and if both emergency diesel generators fail to start and load. During these events it is assumed that there is no seismic event or an event that requires safeguards actuation, e.g., safety injection, containment building spray, etc.

SEPS Design Description The design of the SEPS will meet the criteria set out below:

• The SEPS will include two diesel generator units (gensets) for a size that will handle the required loss of offsite power (LOOP) loads (approximately 4.5 MW).

• The SEPS will be permanently installed south of the Cooling Tower within the plant's Protected Area.

The SEPS genset(s), switchgear and load bank will be housed in individual weather enclosures.

• The SEPS will include a 24-hour fuel oil supply.

• The SEPS will automatically start on a loss of power condition.

• The SEPS gensets will connect to the essential switchgear room via an underground duct bank.

• The SEPS will include a resistive/reactive electrical load bank for testing. It will be sized to accommodate the full load of a SEPS genset.

• SEPS components and subsystems will be protected against the effects of likely weather-related events that may initiate a loss of offsite power event.

• The SEPS gensets and local switchgear will not be designed to meet Class IE or safety system requirements.

• The SEPS will meet the Updated Final Safety Analysis Report (UFSAR) separation requirements.

• Failure of the SEPS components will not adversely affect Class I E power systems.

• The SEPS generators will have electrical separation from the Class IE power system by at least two circuit breakers and one transfer switch in series, one of which will be a Class IE breaker at the Class 1 E bus.

• The SEPS genset output will not be normally connected to the onsite or offsite power systems.

'FPLE Seabrook anticipates that the SEPS will be available at all times, excluding its preventive maintenance.

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S-EPS Reliability The SEPS power source consists of two diesel generators (gensets) that synchronize automatically.

The system fault tree models a failure of one diesel to start, run or synchronize as a failure of the SEPS system. The existing emergency diesel start and run failure data was used for each of the SEPS gensets. Using the EDG failure rate data is believed to be conservative. The SEPS data will be updated to manufacturer specific data when it is made available. The SEPS gensets are skid mounted units and are expected to be more mechanically reliable than the existing emergency diesel generators.

This is based on advances made in diesel reliability and the benefit of a long commercial operating history.

SEPS Availability The SEPS system will be added to the Maintenance Rule program. Contract personnel are expected to maintain the SEPS gensets. Five days of unavailability was assumed for this analysis. Load run testing will occur once per month for no more than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The SEPS gensets will be loaded to 50%

rated capacity using a load bank adjacent to the SEPS gensets. While in test the SEPS will be fully functional and require minimal additional operator action to exit the test. These additional operator actions were not modeled due to their low overall contribution to risk. The SEPS will be made functional before any scheduled entry into the extended EDG AOT.

SEPS Support The SEPS support system failures are not critical to the success of the SEPS and are not included in the SEPS hardware fault tree. Support system failures are readily apparent and do not represent an immediate loss of function. Support power comes from a non-emergency supply that supplies a 480-volt electrical power panel located at the SEPS gensets. The power is used for the battery chargers, lighting, and heating. The loss of a support function is discemable by a control room alarm that indicates SEPS trouble. A local alarm panel shows the specific parameter(s) that are in alarm. A battery low alarm is provided that allows a safety margin for replacing batteries before starting capability is lost. On loss of power to support systems, such as a transformer failure, the SEPS gensets will start and auto-synchronize.

Loss of power to support systems is of particular concern during freezing conditions, thus this provision will ensure the SEPS maintains adequate temperatures.

Operator rounds will also provide an additional level of protection against lost support systems and monitor overall SEPS condition.

EDG Reliability EDG reliability remains unchanged for this evaluation. The EDG failure data is based on a Bayesian update that combines generic data with station specific data and was last updated in 2002.

EDG Unavailability This risk assessment assumes no EDG scheduled maintenance during Modes 2 through 6. All scheduled maintenance is assumed performed in Mode 1. The 14-day AOT is expected to yield some efficiency in maintenance and thereby reduce total unavailability of the EDGs. However, no maintenance scheduling efficiency was assumed for this evaluation. The following Mode I maintenance was added to the PRA model.

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• 'Preventive Maintenance - 7 days every 18 months. This is equivalent to the normal scheduled unavailability in Modes 5 and 6

• Corrective Maintenance - 14 days every 10 years.

This is non-common cause corrective maintenance. A common cause maintenance event would require a plant shutdown.

The additional yearly maintenance is as follows: 7/1.5 + 14/10 = 6.1 days (146 hours0.00169 days <br />0.0406 hours <br />2.414021e-4 weeks <br />5.5553e-5 months <br />).

Seismic Fragility Because there is no information available regarding the seismic capacity of the SEPS, it is assumed that it has modest capacity, equivalent to offsite power. This is modeled by using the same seismic top event as offsite power (QY, median fragility of 0.3g) in the SEPS rules. This assumption is considered to be conservative.

Reactor Coolant Pump Seal LOCA Reactor Coolant Pump Seal LOCA is assumed to occur during station black out. Currently, the SEPS is not capable of restoring power to the charging pump or thermal barrier cooling (PCCW) within 13 minutes. However, a stable reactor coolant system (RCS) state is reached when safety injection and/or the charging pump restores RCS level and emergency feedwater (EFW) is successful in removing decay heat. The most probable seal leak rate is less than or equal to 84 GPM.

Human Reliability The SEPS requires human intervention to energize and load an emergency bus. Normally the SEPS will be aligned to emergency bus E6. In this alignment the breaker for bus E6 is racked onto the bus and in the open position. The control for the breaker is located on the breaker cubicle. The transfer switch, located in Train B essential switchgear, will be pre-positioned to bus E6. On station black out the SEPS gensets will auto-start and come up to rated speed and voltage and synchronize automatically. The emergency operating procedure (ECA 0.0, Loss of All AC Power) for loss of power will be entered directing the operators to manually strip bus E6 loads.

Once stripped, an operator dispatched to the Train B switchgear room closes the SEPS breaker per control room direction which energizes bus E6. The control room operator will load the emergency bus based on a predetermined loading schedule per ECA 0.0.

The EPRI Human Reliability Analysis (HRA) calculator was used to document the human actions required to restore power to an emergency bus using the SEPS using the Human Cognitive Reliability (HCR) / Operator Reliability Experiments (ORE) / Techniques for Human Error Prediction (THERP) methodology. This methodology considers timing dependency and stress on the operators to determine probabilities of the operator failing to load the SEPS properly. The total Human Error Probability (HEP) for failing to load the SEPS was calculated as.055 (5.5E-02).

In very rare cases an additional operator action is required to realign the SEPS to the opposite train (bus E5). One such case is a failure of bus E6. In addition to the above operator actions, the operator in the switchgear room must obtain tools, procedure and protective gear to rack out the breaker at bus E6 and rack in the breaker at bus E5. The operator must then position the transfer switch to bus E5.

The probability of failure for this set of human actions has been conservatively set to 0.5 (SE-01).

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Technical Requirement 31 Supplemental Emergency Power System Availability Requirements (Sheet 1 of 2)

LIMITING CONDITION FOR OPERATION TR 31-3.1 The Supplemental Emergency Power System (SEPS) shall be available for standby service.

APPLICABILITY: At All Times ACTION:

a.

With the requirements of the LCO not satisfied, initiate corrective action to restore the SEPS to available status in a timely fashion.

b.

Whenever an emergency diesel generator (EDG) is inoperable and SEPS is available perform the following additional actions:

1)

Prior to performance of any preplanned emergency diesel generator maintenance activity that is expected to extend beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, perform an operational readiness status check of the SEPS per ACTION b.3) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> prior to removing the selected EDG from service.

2)

During an unplanned corrective maintenance outage with an EDG inoperable and the SEPS available, perform an operational readiness status check of the SEPS per ACTION b.3) prior to exceeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from the time the EDG initially became inoperable.

3)

The operational readiness status check shall consist of the following:

a)

Verifying the SEPS is operationally ready for automatic start and energization of the selected emergency bus; b)

Verifying the fuel oil level in each fuel oil storage tank is greater than or equal to (TBD) percent/gallons; c)

Verifying SEPS 5 kV and 480 V circuit breaker and transfer switch alignment to the selected emergency bus; and d)

Repeating ACTION b.3) at least once every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> thereafter while an EDG is inoperable.

SURVEILLANCE REQUIREMENTS TR 31-4.1 The SEPS shall be demonstrated available:

a.

At least once every 31 days by:

1)

Verifying each diesel starts from manual initiation and attains a steady-state generator voltage and frequency of 4160 + 420 volts and 60 + 1.2 Hz;

2)

Verifying load-sharing capability of each generator while synchronized together;

3)

Verifying SEPS 5 kV and 480 V circuit breaker and transfer switch alignment to the l selected emergency bus; and 2-31.1 SSTR Rev. Draft