SBK-L-14126, Station,Proposed Change to Increase Voltage Limit for Diesel Generator Load Rejection Surveillance Requirement

Station,Proposed Change to Increase Voltage Limit for Diesel Generator Load Rejection Surveillance Requirement

ML14209A918
Person / Time
Site:	Seabrook
Issue date:	07/24/2014
From:	Dean Curtland NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-14126
Download: ML14209A918 (17)

Text

NEXTera ENERGY July 24, 2014 10 CFR 50.90 SBK-L-14126 Docket No. 50-443 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Seabrook Station License Amendment Request 14-02 Proposed Change to Increase Voltage Limit for Diesel Generator Load Rejection Surveillance Requirement Pursuant to 10 CFR 50.90, NextEra Energy Seabrook, LLC (NextEra) is submitting License Amendment Request (LAR) 14-02 to revise the Seabrook Station Technical Specification (TS).

The proposed change increases the voltage limit for a full load rejection test of the emergency diesel generator (EDG) specified in surveillance requirement (SR) 4.8.1.1.2.f.3 of Technical Specification (TS) 3.8.1.1, A.C. Sources - Operating. The LAR also revises the TS definition of the terms "Operable - Operability."

The Enclosure to this letter provides NextEra's evaluation of the proposed change. Attachment 1 to the enclosure provides markups of the TS that show the proposed change. As discussed in the evaluation, the proposed change does not involve a significant hazards consideration pursuant to 10 CFR 50.92, and there are no significant environmental impacts associated with the change.

No new commitments are made as a result of this change.

The Station Operation Review Committee has reviewed this LAR.

In accordance with 10 CFR 50.91, NextEra is notifying the State of New Hampshire of this LAR by transmitting a copy of this letter and enclosure to the designated State Official.

NextEra requests NRC review and approval of LAR 14-02 by August 1, 2015 and implementation within 60 days.

NextEra Energy Seabrook, LLc.

626 Lafayette Rd, Seabrook, NH 03874

United States Nuclear Regulatory Commission SBK-L-14126 / Page 2 Should you have any questions regarding this letter, please contact Mr. Michael Ossing, Licensing Manager, at (603) 773-7512.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on

.k' Y',2014.

Sincerely, Dean Curtland Site Vice President NextEra Energy Seabrook, LLC

Enclosure:

Evaluation of the Proposed Change cc:

NRC Region I Administrator NRC Project Manager NRC Senior Resident Inspector Director Homeland Security and Emergency Management New Hampshire Department of Safety Division of Homeland Security and Emergency Management Bureau of Emergency Management 33 Hazen Drive Concord, NH 03305 Mr. John Giarrusso, Jr., Nuclear Preparedness Manager The Commonwealth of Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702-5399

Enclosure NextEra Energy Seabrook's Evaluation of the Proposed Change

Subject:

Proposed Change to Increase Voltage Limit for Diesel Generator Load Rejection Surveillance Requirement 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 Significant Hazards Consideration 4.4 Conclusion

6.0 REFERENCES

- Markup of the Technical Specifications - Summary of Previous EDG Full Load Rejection Test Results

Evaluation of the Proposed Change 1.0

SUMMARY

DESCRIPTION NextEra Energy Seabrook, LLC (NextEra) proposes to (1) increase the voltage limit for a full load rejection test of the emergency diesel generators (EDG) specified in surveillance requirement (SR) 4.8.1.1.2.f.3 of Technical Specification (TS) 3.8.1.1, A.C. Sources -

Operating, and (2) revise the TS definition of the terms operable - operability.

2.0 DETAILED DESCRIPTION 2.1 EDG Voltage Limit NextEra proposes to revise SR 4.8.1.1.2.f.3 to increase the overvoltage limit for the EDG full load rejection test from 4784V to 4992V:

Verifying the generator capability to reject a load of 6083 kW without tripping.

The generator voltage shall not exceed 47-84 4992 volts during and following the load rejection; SR 4.8.1.1.2.f.3 demonstrates the capability of the generator to reject a load of 6083 kW without tripping. EDG full load rejection may occur because of a system fault or inadvertent breaker tripping. This SR ensures proper engine generator response under simulated test conditions. The test acceptance criteria provide for EDG damage protection. While the EDG is not expected to experience a fault or an inadvertent breaker trip during an event, this testing ensures that the EDG is not degraded for future use, including reconnection to the bus if the trip initiator can be corrected or isolated.

The existing TS overvoltage limit value of 4784V is equal to 115% of generator rated voltage. A technical basis for the specific 4784V value does not exist in any applicable industry or regulatory standards. IEEE 387-1977 [Reference 1], Section 6.4.5, Load Rejection Tests, states that load rejection tests shall demonstrate the capability of rejecting the maximum rated load without exceeding speed or voltage which would cause tripping, mechanical damage, or harmful overstresses. Specific voltage limit values are not provided.

Previous full load rejection test results have shown that not much margin exists between the resultant transient peak voltages and the TS overvoltage limit. See for a summary of past test results.

The existing TS overvoltage limit of 4784V has resulted in past test failures. The cause of the failures was attributed to high grid voltage conditions which resulted in corresponding high voltages on the station emergency buses. In order to obtain the full load value of 6083kW, the EDG must be operated in parallel with offsite power.

When an EDG is operated in parallel with the grid for the purpose of the full load rejection test, the emergency bus voltage is further increased as excitation is adjusted to meet the required VAR loading. If the steady-state bus voltage prior to 1

the full load rejection is too high, the overvoltage transient challenges the existing TS overvoltage limit.

An editorial change is made to the affected TS page to correct four instances of a misspelling of the term buses.

2.2 Definition of OPERABLE - OPERABILITY NextEra proposes to revise TS Definition 1.21, OPERABLE - OPERABILITY, as shown below.

1.21 A system, subsystem, train, component or device shall be OPERABLE or have OPERABILITY when it is capable of performing its specified safety function(s), and when all necessary attendant instrumentation, controls, normal or emergency electrical power, cooling e. and seal water, lubrication, and of other auxiliary equipment that are required for the system, subsystem, train, component, or device to perform its specified safety function(s) are also capable of performing their related support function(s).

3.0 TECHNICAL EVALUATION

3.1 EDG Voltage Limit NextEra proposes an overvoltage limit of 4992V for the EDG full load rejection test.

This value is equal to 120% of the generator rated voltage value of 4160V. This value is approximately 4.35% higher than the existing limit of 4784V and will provide adequate margin based on consideration of past test results.

Past test results show that the transient peak voltage is approximately 9% above the steady-state bus voltage prior to the full load rejection test. The transient peak voltage lasts for less than one second and returns to the steady-state voltage within 4 seconds of the load rejection. Assuming a typical maximum bus voltage prior to the load rejection of 4400V and a typical 9% transient due to the full load rejection, the expected transient peak voltage would be 4796V which is 196V below the 4992V limit.

The revised voltage limit of 4992V has been evaluated to ensure that there will be no component degradation of any connected equipment as a result of overvoltage transients up to the 4992V value. The effects of the increased overvoltage limit of 4992V are analyzed below.

Generator The emergency diesel generator was manufactured by Beloit Power Systems. It is a Type TGZDO with a nominal voltage rating of 4160 volts.

NextEra evaluated why previous voltage excursions on 04/24/05 and 12/07/05 on EDG-1 B did not affect its ability to perform its safety function of providing backup power to the emergency bus. The subject voltage excursions lasted approximately 2

4.7 minutes and 5.3 minutes. The evaluation concluded that a voltage of about 6000 volts, although undesirable, will not damage the generator or exciter components.

An industry criterion for medium voltage designs per ANSI is a high potential test at twice the nominal voltage plus 1000 volts (Standard Handbook for Electrical Engineers, Fink and Beaty, Eleventh Edition). Therefore, the generator voltage would have to exceed 9000 volts to be above the standard factory acceptance values. The Beloit Power Systems Qualification Program performed type testing at 15,000 volts DC phase to phase and phase to ground. Specific qualification testing of the generator also included a puncture test at 9300 volts for one minute. These test voltages exceed the actual voltage during the voltage excursion events and demonstrate that the generator is not impacted in any way by an excursion to about 6000 volts.

As final verification that there was no damage to the generator as a result of the voltage excursion, a Megger test of the winding insulation to ground at 2500 volts was performed right after the 04/24/05 voltage transient with acceptable readings in excess of 350 megohms at one minute. This value is comparable to original factory testing.

The peak voltage transient voltage following a full load rejection only exists for approximately one second. The transient voltage recovers back to a steady-state value within approximately four seconds. A peak voltage transient of 4992V will not have any detrimental effect on the emergency diesel generator insulation system due to its short duration. In addition, previous analysis shows that the 4992V limit is enveloped by factory acceptance test values.

NextEra confirmed with the EDG manufacturer (Fairbanks Morse) that a momentary excursion to 4992V does not pose a risk to the generator and exciter. The basis for this conclusion is that the peak voltage is far below the documented value and duration of the test voltage incurred during hipot testing (9300V) and the very short time duration of the transient.

Control Components The EDG voltage regulator was manufactured by Basler Electric and is a Static Exciter Regulator Model SER-CB.

NextEra confirmed with the EDG voltage regulator manufacturer (MPR/Basler) that a momentary excursion to 4992V does not pose a risk to the generator excitation system. The basis for this conclusion is that during a full load reject, generator stator voltage momentarily increases following the sudden cessation of stator current flow.

The vast majority of the SER-CB excitation system circuitry is powered by the vector combination of power potential transformer (PT) and power current transformer (CT) outputs. During a full load rejection, this portion of the excitation system experiences lower voltages than at full load conditions because the output from the power CT is zero. Accordingly, the portion of the SER-CB that is powered by the power CT and power PT is not overstressed during a full load reject.

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In addition, MPR/Basler identified that the power PTs have the limiting overvoltage rating for the supplied transformers. They are rated for an overvoltage of 1.20 per unit for 10 seconds. Therefore, a peak voltage transient voltage of 4992V for approximately 1 second will not have any detrimental effect on transformers supplied as part of the voltage regulator.

A review was performed for the balance of non-excitation system devices connected to the PT secondary circuits. Considering a PT ratio of 4200-120V, for a 4992V primary voltage, the secondary voltage would be approximately 142.6V. Component overvoltage concerns involve voltage stress and thermal heating. Industry standards typically include dielectric testing at voltage levels appreciably greater than rated insulation voltage to determine the adequacy against insulation breakdown under transient overvoltage conditions which are likely encountered in normal operation (NEMA ICS 1-2000, ANSI/IEEE C37.90-1978). The peak overvoltage transient resulting from a full load rejection has a very short duration, less than a second.

Based on a review of equipment data and specification sheets, it is concluded that these devices have adequate voltage ratings and will not be degraded by the anticipated magnitude and short duration of the overvoltage transient.

Non-Segregated Phase Bus Duct Non-segregated phase bus duct is used to connect the EDG to the 4.16kV switchgear. The non-segregated phase bus duct nominal voltage rating is 4.16kV, the maximum continuous voltage rating is 4.76kV, the one minute dry withstand voltage rating is 19kV rms, and the full wave impulse withstand voltage rating is 60kV. Since the one minute dry withstand voltage rating (19kV) significantly exceeds the proposed full load rejection overvoltage limit of 4992V, the bus duct will not experience any detrimental effects due to very short duration voltage transients up to 4992V.

4.16 kV Switchqear The switchgear nominal voltage rating is 4.16kV, the maximum continuous voltage rating is 4.76kV, the one minute low frequency withstand voltage rating is 19kV rms, and the full wave impulse withstand voltage rating is 60kV. Since the low frequency withstand voltage rating (19kV) significantly exceeds the proposed full load rejection overvoltage limit of 4992V, the switchgear will not experience any detrimental effects due to very short duration voltage transients up to 4992V.

3.2 Definition of OPERABLE - OPERABILITY The proposed changes to the definition of OPERABLE - OPERABLITY make grammatical corrections and clarify the definition with regard to electrical power. The changes are administrative in nature and do not alter the meaning of the terms operable and operability. The proposed changes make the definition consistent with the definition in NUREG-1431, Standard Technical Specifications - Westinghouse Plants [Reference 7].

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4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria Seabrook UFSAR section 8.1.5.2 states that the onsite power system conforms to General Design Criteria (GDC) 2, 4, 5, 17, and 18.

GDC 2-Design bases for protection against natural phenomena requires that structures, systems, and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions.

GDC 4-Environmental and dynamic effects design bases requires structures, systems, and components important to safety shall be designed to accommodate the effects of and to be compatible with the environmental conditions associated with normal operation, maintenance, testing, and postulated accidents, including loss-of-coolant accidents.

GDC 5-Sharing of structures, systems, and components states that structures, systems, and components important to safety shall not be shared among nuclear power units unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions, including, in the event of an accident in one unit, an orderly shutdown and cooldown of the remaining units.

GDC 17-Electric power systems requires an onsite electric power system and an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety.

The safety function for each system (assuming the other system is not functioning) shall be to provide sufficient capacity and capability to assure that (1) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents.

The onsite electric power supplies shall have sufficient independence, redundancy, and testability to perform their safety functions assuming a single failure. Electric power from the transmission network to the onsite electric distribution system shall be supplied by two physically independent circuits.

Provisions shall be included to minimize the probability of losing electric power from any of the remaining supplies as a result of, or coincident with, the loss of power generated by the nuclear power unit, the loss of power from the transmission network, or the loss of power from the onsite electric power supplies.

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GDC 18-Inspection and testing of electric power systems. Electric power systems important to safety shall be designed to permit appropriate periodic inspection and testing of important areas and features, such as wiring, insulation, connections, and switchboards, to assess the continuity of the systems and the condition of their components.

Seabrook meets the requirements of IEEE 387-1977, IEEE Standard Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear Power Generating Stations, and Regulatory Guide 1.9, Selection, Design, and Qualification of Diesel Generator Units Used as Standby (Onsite) Electric Power Systems at Nuclear Power Plants [Reference 2].

10 CFR 50.36, Technical specifications, establishes the regulatory requirements for the contents of the TS. Surveillance requirements, which are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met, must be included in the TS.

The proposed changes comply with the above requirements.

4.2 Precedent The NRC has approved similar license amendments that increase the EDG full load rejection voltage limit specified in the TS:

Amendment No. 170 to Facility Operating License No. DPR-77 and Amendment 160 to Facility Operating License No. DPR-79 for Sequoyah Units 1 and 2, respectively, August 27, 1993 [Reference 3]

Amendment No. 140 to Facility Operating License No. NPF-43 for Fermi 2, May 9, 2000 [Reference 4]

" Amendment No. 276 to Facility Operating License No. DPR-74 for D.C.

Cook, Unit 2, April 13, 2006 [Reference 5]

" Amendment No. 206 to Renewed Facility Operating License No. NPF 42 for Wolf Creek, December 2, 2013 [Reference 6]

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4.3 No Significant Hazards Consideration NextEra has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10CFR50.92, "Issuance of Amendment," as discussed below:

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change to increase in the EDG full load rejection overvoltage limit from 4784V to 4992V is not an accident initiator. The overvoltage transient is an expected response to a full load rejection. The magnitude and duration of the proposed overvoltage limit have been considered and determined to have no detrimental effects on the connected equipment that is exposed to the voltage transient. The proposed change does not affect the EDG design function or how the EDG is operated. Since the EDG is not impacted, the EDG remains capable of performing its intended design function of supplying power to emergency safeguards equipment. The proposed change to the definition of operable - operability is administrative in nature and does not alter the meaning of the defined terms. Therefore, the proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any previously evaluated?

Response: No The proposed changes to revise the definition of the terms operable -

operability and to increase the EDG full load rejection overvoltage limit from 4784V to 4992V are not accident initiators. The overvoltage transient is an expected response to a full load rejection. The magnitude and duration of the proposed overvoltage limit have been considered and determined to have no detrimental effects on the connected equipment that is exposed to the voltage transient. The proposed changes do not introduce any new failure modes.

The changes do not involve a physical alteration to the plant (i.e., no new or different type of equipment will be installed) or a change in the methods for operating the plant. The proposed changes do not affect the EDG design function or how the EDG is operated. Since the EDG is not impacted, the EDG remains capable of performing its intended design function of supplying power to emergency safeguards equipment. The change to the definition of operable - operability makes grammatical corrections and adds clarity but makes no change to the meaning of the terms. Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any previously evaluated.

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3. Does the proposed change involve a significant reduction in the margin of safety?

Response: No.

The proposed change to increase in the EDG full load rejection overvoltage limit from 4784V to 4992V has been evaluated with consideration of the effect on the EDG and connected equipment that would be exposed to the higher voltage transient. Based on review of equipment specifications, test data, and manufacturer's input, it was concluded that there would be no detrimental effects to the EDG or connected equipment that is exposed to the higher voltage transient. The EDG remains capable of performing its intended design function of supplying power to emergency safeguards equipment.

The proposed change to the definition of operable - operability is administrative in nature and does not alter any criterion used to establish operability of plant structure, systems, or components.

The proposed amendment does not involve changes to any safety analyses assumptions, safety limits, or limiting safety system settings. The changes do not adversely impact plant operating margins or the reliability of equipment credited in the safety analyses. Therefore, the proposed changes do not involve a significant reduction in the margin of safety.

Based on the above, NextEra concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10CFR50.92(c) and, accordingly, a finding of "no significant hazards consideration" is justified.

4.4 Conclusions In conclusion, based on the considerations above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the general public.

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5.0 ENVIRONMENTAL CONSIDERATION

NextEra has evaluated the proposed amendment for environmental considerations. The review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 1 0CFR20, or would change an inspection or surveillance requirement.

However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase 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 10CFR51.22(c)(9).

Therefore, pursuant to 10CFR51.22(b), no environmental impact statement or environmental assessment needs to be prepared in connection with the proposed amendment.

6.0 REFERENCES

1.

IEEE 387-1977, IEEE Standard Design Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear Power Generating Stations

2.

Regulatory Guide 1.9, Selection, Design, and Qualification of Diesel Generator Units Used as Standby (Onsite) Electric Power Systems at Nuclear Power Plants, Revision 2, December 1979

3.

Sequoyah Units 1 and 2, Issuance of Amendments (TAC Nos. M85950 and M85951) (TS 93-03), dated August 27, 1993 (ML013310260)

4.

Fermi 2 - Issuance of Amendment RE: Emergency Diesel Generator Full-Load Reject Overvoltage Limit (TAC No. MA8881), dated May 9, 2000 (ML003713918)

5.

Donald C. Cook Nuclear Plant, Unit 2 DCCNP-2) - Issuance of Amendment Under Emergency Circumstances Regarding Diesel Generator Voltage Limit Requirements (TAC No. MD1131), April 13, 2006 (ML061010512)

6.

Wolf Creek Generating Station - Issuance of Amendment Re: Revise Technical Specification 3.8.1, "AC Sources - Operating" (TAC No. ME9603), December 2, 2013 (ML13282A147)

7.

NUREGO1431, Standard Technical Specifications - Westinghouse Plants, Revision 4.0, April 2012 9

Markup of the Technical Specifications

DEFINITIONS

b.

Leakage into the containment atmosphere from sources that are both specifically located and known either not to interfere with the operation of Leakage Detection Systems or not to be PRESSURE BOUNDARY LEAKAGE, or

c.

Reactor Coolant System leakage through a steam generator to the Secondary Coolant System (primary to secondary leakage).

MASTER RELAY TEST 1.18 A MASTER RELAY TEST shall be the energization of each master relay and verification of OPERABILITY of each relay. The MASTER RELAY TEST shall include, a continuity check of each associated slave relay.

MEMBER(S) OF THE PUBLIC 1.19 MEMBER(S) OF THE PUBLIC shall include all persons who are not occupationally associated with the plant. This category does not include employees of the licensee, its contractors, or vendors. Also excluded from this category are persons who enter the site to service equipment or to make deliveries. This category does include persons who use portions of the site for recreational, occupational, or other purposes not associated with the plant.

OFFSITE DOSE CALCULATION MANUAL 1.20 The OFFSITE DOSE CALCULATION MANUAL (ODCM) shall contain the methodology and parameters used in the calculation of offsite doses resulting from radioactive gaseous and liquid effluents, in the calculation of gaseous and liquid effluent monitoring Alarm/Trip Setpoints, and in the conduct of the Environmental Radiological Monitoring Program. The ODCM shall also contain (1) the Radioactive Effluent Controls and Radiological Environmental Monitoring Programs required by Section 6.7.6 and (2) descriptions of the information that should be included in the Annual Radiological Environmental Operating and Annual Radioactive Effluent Release Reports required by Specifications 6.8.1.3 and 6.8.1.4.

OPERABLE - OPERABILITY

[normal or emergency safety'a 1.21 A system, subsystem, train, component or evice shabe OPERABL or have OPERABILITY when it is capable of performings specified function(s), a _ when all necessary attendant instrumentation, controls, electrical power, cooling of seal water, lubrication-oF other auxiliary equipment that are required for the system, subsystem, train, component, *Xl.device to perform its function(s) are also capable of performing their related support function(s' s

ce s-af-e OPERATIONAL MODE - MODE 1.22 An OPERATIONAL MODE (i.e., MODE) shall correspond to any one inclusive combination of core reactivity condition, power level, and average reactor coolant temperature specified in Table 1.2.

SEABROOK - UNIT 1 1-4 Amendment No. 7--8Q, 668-1-, -145

ELECTRICAL POWER SYSTEMS A.C. SOURCES OPERATING SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued)

f.

At least once per 18 months, during shutdown

, by: -

1)

(NOT USED)

2)

Verifying the generator capability to reject a load of greater than or equal to 671 kW while maintaining voltage at 4160 + 420 volts and frequency at 60 + 4.0 Hz;

3)

Verifying the generator capability to reject a load of 6083 kW without tripping. The generator voltage shall not exceed 4784 volts during and following the load rejection;

4)

Simulating a loss-of-offsite power by itself, and:

a)

Verifying deenergization of the emergency busses and load shedding from the emergency busies, and b)

Verifying the diesel starts from standby conditions### on the loss 'I of offsite power signal, energizes the emergency bus~es with permanently connected loads within 12 seconds, energizes the auto-connected shutdown loads through the emergency power sequencer and operates for greater than or equal to 5 minutes while its generator is loaded with the shutdown loads. After energization, the steady-state voltage and frequency of the emergency buss'es shall be maintained at 4160 +/- 420 volts and 60 +/- 1.2 Hz during this test.

5)

Verifying that on an SI actuation test signal, without loss-of-offsite power, the diesel generator starts from standby conditions?

on the

]'

auto-start signal and operates on standby for greater than or equal to 5 minutes. The generator voltage and frequency shall be greater than or equal to 3740 volts and 58.8 Hz within 10 seconds after the auto-start signal; the steady-state generator voltage and frequency shall be maintained at 4160 +/- 420 volts and 60 +/- 1.2 Hz during this test;

1. 1. Selected surveillance requirements, or portions thereof, may be performed during conditions or modes other than shutdown, provided an evaluation supports safe conduct of that surveillance in a condition or mode that is consistent with safe operation of the plant. (Ref. NRC GL 91-04)

1. 1. 1. Starting of the diesel for Specifications 4.8.1.1.2f.4) and 4.8.1.1.2f.5) may be performed with the engine at or near normal operating temperature.

SEABROOK - UNIT 1 3/4 8-5 Amendment No. 54, 7-1-, 7-, 80 Summary of Previous EDG Full Load Rejection Test Results Summary of Previous EDG Full Load Rejection Test Results During refueling outage OR1 5 (October 2012) EDG-1 B failed to meet the Technical Specification full load rejection overvoltage limit of 4784V. NextEra reviewed previous test results for EDG full load rejection testing. The following is a summary:

OUTAGE EDG-1A EDG-1B 4760V ORll October 2006 OR12 April 2008 OR13 October 2009 OR14 April 2011 OR15 October 2012 OR16 April 2014 4750V 4700V 4710V 4725V 4730V 4725V 4810V (4760V) 4780V 4750V 4785V (<4784V) 4730V Notes:

The 4810V value from OR12 was a test failure. The test was repeated with a lower bus voltage pre-event and the resultant voltage was 4760V.

The 4785V value from OR1 5 was initially identified as a test failure. After further evaluation of loop accuracy, it was concluded that the actual voltage was less than 4784V.