ML20129B776

Proposed Tech Specs,Consisting of Change Request 96-06, Proposing Four Changes Re EDG Requirements Contained in TS 3/4.8.1, AC Sources

ML20129B776
Person / Time
Site:	Seabrook
Issue date:	10/16/1996
From:	NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:
Shared Package
ML20129B745	List: ML20129B741 ML20129B763 ML20129B776
References
NUDOCS 9610230109
Download: ML20129B776 (15)

Text

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3/4.8 ELECTRICAL POWER SYSTEMS

, 3/4.8.1 A.C. SOURCES ,

l .-

j OPERATING -

LIMITING CONDITION FOR OPERATION l

i 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE:

. a. Two physically independent circuits between the offsite i transmission network and the onsite class 1E Distribution System, and i

i b. Two separate and independent diesel generators, each with:

i

1) A separate day fuel . tank containing a minimum fuel volume 4

fraction of 3/8 (600 gallons),

2) As uel Storage System containing a min'imum volume

of 'G,000 gallons of fuel, i

' 62. o0 0

3) A sepa, rate fuel transfer pump,

{

, 4) Lubricating oil storage containing a minimum total volume of i 275 gallons of lubricating oil, and

. 5) Capability to transfer lubricating oil from storage to the diesel generator unit.

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

ACTION:

a. With an offsite circuit of the above required A.C. electrical l p'ower sources inoperable, demonstrate the OPERABILITY of the remaining A.C. source by performing Specification 4.8.1.1.la.

within I hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least two offsite circuits to OPERABLE status 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 />.

4 9610230109 961016 PDR ADOCK 05000443 P PDR SEABROOK - UNIT 1 3/4 8-1 Amendment No. W '

t>rrER

i ELECTRICAL POWER SYSTEMS

' l A.C. SOURCES i

OPERATING i

SURVEILLANCE REQUIREMENTS 1

4.8.1.1.2 (Continued) b) A kinematic viscosity at 40*C of greater than or equal to

! 1.9 centistokes, but less than or equal to 4.1 centistokes, if gravity wa's not determined by comparison with the supplier's certification; c) A flash point greater than or equal to 125'F; and i

' d) A clear and bright appearance with proper color when tested in accordance with ASTM-04176-82.

j

2) By verifying within 30 days of obtaining the sample that the 1

- other properties specified in Table 1 of ASTM-0975-81 are met

when tested in accordance with ASTM-0975-81 except that the i analysis for sulfur may be performed in accordance with

. ASTM-01552-79 or ASTM-D2622-82.

e. At least once every 31 days:

1) By obtaining a sample of fuel oil in accordance with ASTM-02276-78, i and verifying that total particulate contamination is less than j 10 mg/ liter when checked in accordance with ASTM-02276-78, Method A, and I s

2)

By visually inspecting the lagging in the area of the flanged joints on the silencer outlet of the diesel exhaust system for leakage (also after an extended operation of greater than 24 '

j hours).

j f. At least once per 18 months, during shutdowrt, y:

1) Subjecting the diesel to an inspection in accordance with procedures prepared in conjunction with its manufacturer's recommendations for this class of standby service;

2) Verifying the generator capability to reject a load of greater than or equal to 671 kW while maintaining voltage at 4160 t 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:

SEABROOK 3/4 8-5

, n ccAvortoks

, _- UNIT 1- -acn a~r w a --a,,.,,/ h nm

}

oRrtows cracn rwAA raanwa ?> tom

• A 'o crR so.s1 CArcry EW1M/CA sqenas Sapr copucT of rarfautm-AAce sA A coAmriaa on >uope Tar is coMtMA g(

wra rar omme A c F T?re Puer. (, RE F. rtac. Gs. 96-vy)

, ELECTRICAL POWER SYSTEMS LC. SOURCES OPERATING SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued)

10) Verifying that with the die ul generator operating in a test mode, connected to its bus, a simulated Safety Injection

' signal overrides the test mode by: (1) returning the diesel generator to standby operation, and (2) automatically energizing the emergency loads with cffsite power;

11) Verifying that the fuel transfer pump tractfers fuel from each fuel storage tank to the day tank of e v.h diesel via the installed cross-connection lines;

12) Verifying that the emergene oower sequence timer is OPERABLE with the interval between eso load block within i 10% of its design interval;

13) Verifying that the following diesel generator lockout '

features prevent diesel generator starting: t a) Barring device engaged, or b) Differential lockout relay.

14) Simulating a Tower Actuation (TA) signal while the diesel generator is loaded with the permanently connected loads and auto-connected emergency (accident) loads, and verifying that the service water 11y trips, and that the cooling tower pump . . . . automatically start C After energization the s e voltage and frequency of the emergency buses shall be maintained at 4160 i 420 volts and 60 i 1.2 Hz; and

15) While diesel generator IA is loaded with the permanently connected loads and auto-connected emergency (accident) loads, manually connect the 1500 hp startup feedwater pump to 4160-volt bus E5. After energization the steady-state voltage and frequency of the emergency bus shall be maintained at 4160 i 420 volts and 60 i 1.2 Hz.

g. At least once per 10 years' or after any modifications which could affect diesel generator interdependence by starting both diesel generators simultaneously, during shutdown, and verifying that both diesel generators accelerate to 60 i 1.2 Hz in less than or equal l to 10 seconds; and SEABROOK - UNIT 1 3/4 8-8 Amendment No. M-LATER.

Ejl,ECTRICALPOWERSYSTEMS A.C. SOURCES OPERATING SURVEILLANCE REQUIREMENTS 4.8.1.1.2(Continued) I h.

At 1past once per 10 years by[ g l

1) hraining each fuel oil storage tank, removing the accumulated  !

sediment and cleaning the tank using a sodium hypochlorite I solution, or equivalent, and  !

1 2)

-nw ws~vw//v Performing a pressure test of those portions of the diesel fuel l

I oil system designed to Section III subsection ND of the ASME 9

Codeatatestpressureequalto1i0%ofthesystemdesign 9 ue I 4.8.1.1.3 Reports - All diesel generator failures, valid or nonvalid shall be reportea to the Commission in a Special Report pursuant to Specific,ation 6.8.2 within 30 days. Reports of diesel generator failures shall include the informa-l I

tion recommended in Regulatory Position C.3.b of Regulatory Guide 1.108, Revi-sion 1, August 1977.

If the number of failures in the last 100 valid tests (on j a per nuclear unit basis) is greater than or equal to 7, the report shall be supplemented to include the additional information recommended in Regulatory Position C.3.b of Regulatory Guide 1.108, Revision 1, August 1977.

ud SEABROOK - UNIT 1 3/4 8-9 Amendment No. it

~

E SECTION III Retype of Proposed Changes

\

Page 10

1 1

3/4 8 ELECTRICAL POWER SYSTEMS 3/4.8.1 A.C. SOURCES OPERATING LIMITING CONDITION FOR OPERATION 3.8.1.1 As a minimum, the following A.C. electrical power sources shall be OPERABLE:

a. Two physically inde)endent circuits between the offsite transmission networc and the onsite Class 1E Distribution System, and

b. Two separate and independent diesel generators, each with:

1) A separate day fuel tank containing a minimum fuel volume fraction of 3/8 (600 gallons),

2) A separate Fuel Storage System containing a minimum volume of 62,000 gallons of fuel, j  !

3) A separate fuel transfer pump,

4) Lubricating oil storage coricaining a minimum total volume of 275 gallons of lubricating oil, and

5) Capability to transfer lubricating oil from storage to the diesel generator unit. l APPLICABILITY: MODES 1, 2, 3, and 4.

, ACTION:

a. With an offsite circuit of the above required A.C. electrical power l sources inoperable, demonstrate the OPERABILITY of the remaining l A.C. source by performing Specification 4.8.1.1.la. within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> l and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least two I offsite circuits to OPERABLE status 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 />.

l l

l l

SEABROOK - UNIT 1 3/4 8-1 Amendment No. 30,

. - - . _ _ . - - - . - - . - - - ... - ~ ~. - - - -.- . - . - . _ - - . . _ .

1 .

ELECTRICAL POWER SYSTEMS l' A.C. SOURCES I

OPERATING

! SURVEILLANCE REOUIREMENTS i

l 4.8.1.1.2 (Continued) b) 'A kinematic viscosity at 40 C of greater than or equal to 1.9 centistokes, but less than or equal to 4.1 ,

1 centistokes, if gravity was not determined by- 1

comparison with the supplier's certification

, c) A flash point greater than or equal to 125 F: and~

t d) A clear and bright appearance with proper color when tested in accordance with ASTM-D4176-82.

! 2) By verifying within 30 days of obtaining the sample that the 4

other properties specified in Table 1 of ASTM-0975-81 are met when tested in accordance with ASTM-D975-81 except,that the

analysis for sulfur may be performed in accordance with l j ASTM-D1552-79 or ASTM-D?622-82.

4

e. At least once every 31 days

i i 1) By obtaining a sample of fuel oil in accordance with j ASTM-D2276-78, and verifying that total ) articulate l contamination is less than 10 mg/ liter w1en checked in '

i accordance with ASTM-D2276-78. Method A. and

}

i 2) By visually inspecting the lagging in the area of the flanged

}

i joints on the silencer outlet of the diesel exhaust system for leakage (also after an extended operation of greater than j 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />).

l f. At least once per 18 months, during shutdown' by:

1 1) Subjecting the diesel to an inspection in accordance with j procedures prepared in conjunction with its manufacturer's j recommendations for this class of standby service:

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 t 4.0 Hz;

' selected surveillance requirements or portions thereof, may be '

performed during conditions or modes other than shutdown, provided a 10 CFR 50.59 Safety 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)

SEABROOK - UNIT 1 3/4 8-5 Amendment No.

ELECTRICAL PGWER SYSTEMS A.C. SOURCES OPERATING SURVEILLANCE RE0UIREMENTS 4.8.1.1.2 (Continued)

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 busses, and b) Verifying the diesel starts from standby conditions on the loss of offsite power signal, energizes the emergency busses 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 i energization, the steady-state voltage and frequency of the emergency busses 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 4160 420 volts and 60 1.2 Hz within 10 seconds after the auto-start signal: the steady-state generator voltage and frequency shall be maintained within these limits during this test;

6) Simulating a loss-of-offsite power in conjunction with an SI actuation test signal; and a) Verifying deenergization of the emergency busses and load shedding from the emergency busses; b) Verifying the diesel starts from standby conditions, on the auto-start signal, energizes the emergency busses with ,

permanently connected loads within 10 seconds, energizes the '

auto-connected emergency (accident) loads through the emergency power sequencer and operates for greater than or equal to 5 minutes while its generator is loaded with the emergency loads. After energization, the steady-state voltage and frequency of the emergency busses shall be maintained at 4160 420 volts and 60 1 1.2 Hz during this test: and c) Verifying that all automatic diesel generator trips, except engine overspeed low lube oil pressure, 4160-volt bus fault, and generator differential, are automatically bypassed upon loss of voltage on the emergency bus concurrent with a Safety Injection actuation signal.

SEABROOK - UNIT 1 3/4 8-6 Amendment No. 13

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

10) Verifying that with the diesel generator operating in a test mode, connected to its bus, a simulated Safety Injecticn signal overrides the test mode by: (1) returning the diesel generator to standby operation, and (2) automatically energizing the emergency loads with offsite power:

11) Verifying that the fuel transfer pump transfers fuel from each fuel storage tank to the day tank of each diesol via the installed cross-connection lines:

12) Verifying that the emergency )ower sequence timer is OPERABLE with the interval between eac1 load block within 10% of its design interval:

13) Verifying that the following diesel generator lockout features prevent diesel generator starting:

a) Barring device engaged, or b) Differential lockout relay.

14) Simulating a Tower Actuation (TA) signal while the diesel generator is loaded with the permanently connected loads and auto-connected emergency (accident) loads, and verifying that the service water pump automatically trips, and that the cooling tower pump automatically starts. After energization l the steady state voltage and frequency of the emergency buses shall be maintained at 4160 i 420 volts and 60 1.2 Hz: and

15) While diesel generator 1A is loaded with the permanently connected loads and auto-connected emergency (accident) loads, manually connect the 1500 hp startup feedwater pump to 4160-volt bus E5. After energization the steady-state voltage and frequency of the emergency bus shall be maintained at 4160 420 volts and 60 1.2 Hz.

g. At least once per 10 years or after any modifications which could affect diesel generator interdependence by starting both diesel generators simultaneously, during shutdown, and verifying that both diesel generators accelerate to 60 1.2 Hz in less than or equal to 10 seconds; and SEABROOK - UNIT 1 3/4 8-8 Amendment No. 43, 38,

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

h. At least once per 10 years by draining each fuel oil storage tank, removing the accumulated sediment and cleaning the tank using a sodium hypochlorite solution, or equivalent.

4.8.1.1.3 Reoorts - All diesel generator failures, valid or nonvalid, shall be reported to the Commission ;n a Special Report pursuant to Specification 6.8.2 within 30 days. Reports of diesel generator failures shall include the information recommended in Regulatory Position C.3.b of Regulatory Guide 1.108, Revision 1. August 1977. If the number of failures in the last 100 valid tests (on a per nuclear unit basis) is greater than or equal to 7, the report shall be supplemented to include the additional information recommended in Regulatory Position C.3.b of Regulatory Guide 1.108. Revision 1. August 1977.

P SEABROOK - UNIT 1 3/4 8-9 Amendment No. 43.

e i

Section IV Determination of Significant IIazards for Proposed Changes Page 11

f IV. DETERMINATION OF SIGNIFICANT HAZARDS FOR PROPOSED CHANGES License Amendment Request (LAR) 96-06 proposes four changes related to emergency diesel generator (EDG) requirements contained in Technical Specification (TS) 3/4.8.1, "AC Sources".

In accordance with 10CFR50.92, North Atlantic has reviewed the attached proposed changes and has concluded that they 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. Theprcposed changes do not involve a sign.ficant increase in the probability or consequences cf L an accidentpreviously evaluated.

i. Minimum Volume; Limiting Condition for Operation (LCO) 3.8.1.1.b.2 - The proposed change i

increases the minimum EDG fuel oil storage requirement from 60,000 gallons. The minimum i

EDG fuel storage requirement ensures that the EDG has a minimum of a 7 day supply of fuel oil to meet the maximum Engineered Safety Feature load requirements following a Loss Of Power (LOP) and a design basis accident as described in Updated Final Safety Analysis Report (UFSAR) Section 9.5.4.1, Diesel Generator Fuel Oil Storage and Tramfer System - Design Basis. The proposed increase in the minimum volume storage requirement is conservative and ensures the 7 day supply of fuel requirement for the EDG's. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

l ii. Surveillance Testing; Surveillance Requirement (SR) 4.8.1.1.2.f - The proposed change qualifies the requirement to perform EDG surveillance requirements "during shutdown".

Because the terms " Hot and Cold Shutdown" are defined in the TSs as operating modes or conditions, the added restriction to perform certain surveillances during shutdown may be misinterpreted, as noted in NRC Generic Letter 91-04. This change will permit certain maintenance and testing activities to be performed during conditions or modes other than shutdown.

The proposed change to SR 4.8.1.1.2.f does not alter the intent or the method by which the surveillance activities are conducted. In addition, the acceptance criterion for the surveillance's is unchanged. As such, the proposed changes will not degrade the ability of the EDG's to l l perform their safety function. The proposed change will not change the response of an EDG to a Loss of Power as described in the Seabrook Station Updated Final Safety Analysis Report (UFSAR). Since the plant response to an accident will not change, there is no change in the potential for an increase in the consequences of an accident previously analyzed. And, since a failure of an EDG cannot cause any of the accidents evaluated in the UFSAR, the proposed change does not adversely affect the probability or consequences of an accident previously analynd.

l Page 12

e iii. Surveillance Testing; SR 4.8.1.1.2.f.14 - The proposed change deletes the reference to the automatic start of the cooling tower fans on a Tower Actuation. The cooling tower functions as the ultimate heat sink following a seismic event which results in blockage of the circulating water tunnels and therefore a loss of service water. The automatic start function of the cooling tower fans has been defeated by placing the control switch in Pull-to-Lock, based on the issuance of Amendment 18. The proposed change to delete the automatic fan start reference from SR 4.8.1.1.2.f.14 is administrative only, based on; issuance of Amendment 18, the defeat of the automatic fan start and the implementation of a manual start as outlined in License Amendment Request (LAR) 92-13. As part of the Staff's evaluation in Amendment 18, they concluded that;

" Based on the period of time available to initiate cooling tower fans and sprays determined by analysis, the availability of procedures, the relevant operator training, and the accessibility of the cooling tower fan and spray bypass valve controls, the staff concludes that there is adequate assurance that the cooling tower will operate properly to remove the necessary heat with manual initiation of the cooling tower fans and sprays. In addition, procedures to manually initiate cooling tower fans and sprays under cold weather conditions provide protection frcm damage potentially resulting from fan operation with excessive ice accumult. tion and degraded performance of the cooling tower due to ice blocking flow through the fill tile."

The discussion, evaluations and conclusions presented in LAR 92-13 (dated September 30,1992) and Amendment 18 are applicable to the deletion of the automatic fan start reference from SR 4.8.1.1.2.f.14. Based on the evaluations in LAR 92-13 and Amendment 18, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

iv. Pressure Testing; SR 4.8.1.1.2.h.2 - The proposed change deletes the requirement to pressure test certain EDO fuel oil piping. The configuration of the EDG fuel oil system as currently installed and operated is such that a pressure test at i10% of the design pressure would be impractical to perform. The system contains tanks designed for atmospheric pressure and isolation of them and their vent lines from the specified pressure test is not practical. The ASME Code,Section XI, including applicable ASME Code Cases as authorized by the NRC, provides alternate test methods to use in lieu of a l 10% hydrostatic pressure test. By deleting this SR, the provisions of SR 4.0.5 and the ASME Code, along with usage of NRC authorized Code Cases, can be utilized as an equivalent testing requirement to ensure the integrity of the diesel fuel oil system. Deletion of this SR will not prevent the diesel fuel-oil system of performing its intended safety function. Therefore, the proposed TS change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2 The prcposed changes do not create the possibility cf a new or djerent kind cf accidentfrom anypreviously analy:ed.

i.

Minimum Volume; LCO 3.8.1.1.b.2 - The analysis supporting the requested fuel storage requirement increase uses actual EDG performance data from previous 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> EDG load tests and also accounts for possible variations in fuel oil specific gravity, heating value of the fuel, and ambient conditions. Including the variations of fuel properties in the EDG fuel oil consumption analysis results in an increase in the fuel storage system minimum volume requirement to 62,000 Page 13

gallons. This proposed change to the minimum fuel storage requirement does not creat: the possibility of a new or different kind of accident from any previously analyzed.

ii. Surveillance Testing; SR 4.8.1.1.2.f - The proposed change to qualify the EDG 18 month shutdown surveillance requirement to allow the option (as supported by a 10CFR50.59 safety evaluation) of performing selected SR's, or portions thereof, during conditions or modes other than during shutdown does not affect the operation or respo,se of any plant equipment, including the EDG, or introduce any new failure mechanism. The proposed change does not affect the test acceptance criteria of the EDG's. Plant systems and equipment will respond per design and analyses, and there will not be a malfunction of a new or different type introduced by the proposed change to SR 4.8.1.L2.f. As such, the proposed change does not create the possibility of a new or different kind of accident from any previously analyzed.

iii. Surveillance Testing; SR 4.8.1.1.2.f.14 - Amendment 18 to the Seabrook Station Operating License approved the change in the cooling tower operating mode from automatic actuation to manual actuation. Manual control of the cooling tower will not adversely affect the availability of the cooling tower or its heat removal capability. No credible failure mechanism is created by manual control of the cooling tower which could result in the initittion of an accident. The discussion, evaluations and conclusions oresented in LAR 92-13 (dated Feptember 30,1992) and Amendment 18 are applicable to the deletion of the automatic fan , tart reference from SR 4.8.1.1.2.f.14. Based on the evaluations in LAR 92-13 and Amendmnt 18, the proposed change does not create the possibility of a new or different kind of acident from any previously analyzed.

iv. Pressure Testing; SR 4.8.1.1.2.h.2 - There are no design changes being made that would create a new type of accident or malfunction and plant operations remain unchanged. SR 4.8.1.1.2.h.2 is not needed since SR 4.0.5 provides an equivalent surveillance requirement for the EDG fuel oil system using methods acceptable per Section XI of the ASME Code, applicable ASME Code Cases as authorized by the NRC, and Regulatory Guide (RG) 1.137, " Fuel-Oil Systems at Nuclear Power Plants," Revision I, October 1979. Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously analyzed.

3 The prcposed changes do not involve a sign.ficant reduction in the margin cfscfety.

i. Minimum Volume; LCO 3.8.1.1.b.2 - There are no changes being made to the safety limits or safety system settings that would adversely impact plant safety. The proposed change does not affect the EDG's ability to ensure that sufficient power is available to supply the safety related equipment required for: 1) the safe shutdown of the facility, and 2) the mitigation and control of accident conditions within the facility. In addition, the proposed change does not affect the EDG's ability to ensure that: 1) the facility can be maintained in a shutdown or refueling condition for extended periods of time, and 2) sufficieat instrumentation and control capability is available for monitoring and maintaining the unit status. Therefore, the proposed change does not involve a significant reduction in the margin of safety.

Page 14

ii. Surveillance Testing; SR 4.8.1.1.2.f- This change will permit certain maintenance and testing activities to be performed during conditions or modes other than shutdown, as supported by a 10CFR50.59 safety evaluation. In addition, maintenance and testing activities evaluated as safe to be performed during a condition or mode other than shutdown (e.g., on-line maintenance) will receive the appropriate programatically required reviews such that the scheduled work activities do not exceed or cause to exceed Safety System Performance Goals or Maintenance Rule system / component unavailability time and do not result in a significant reduction in the margin of safety.

The bases for TS 3/4.8, " Electrical Power Systems", state that the operability of the AC and DC power systems and associated distribution systems ensure that sufficient power will be available to supply the safety-related equipment required for safe shutdown and mitigation and control of accident conditions. The bases also state that the SR's for determining the operability of the EDG's are in accordance with RG 1.108, Revision 1. These SR's establish maintenance and tests to ensure and verify that the EDG's are operable. Operable EDG's ensure that the assumptions in the bases of the TSs are not affected and ensure that the margin of safety is not reduced. The assumptions in the bases of the TSs are not affected by the proposed change; therefore, this change does not result in a significant reduction in the margin of safety.

iii. Surveillance Testing; SR 4.8.1.1.2.f.14 - This change revises SR 4.8.1.1.2.f.14 to delete the reference to the automatic start of the cooling tower fans. As discussed in LAR 92-13 and Amendment 18 to the Seabrook Station Operating License, sufficient time is available to initiate cooling tower sprays and fans following the seismic event which results in collapse of the circulating water tunnels, loss of offsite power, and a Loss of Coolant Accident. Following this manual action, the full capability of the cooling tower ultimate heat sink is available to meet the requirements of this Technical Specification. Therefore, there is no't a'significant reduction in the margin of safety.

iv. Pressure Testing; SR 4.8.1.1.2.h.2 - There are no changes being made to the safety limits or safety system scitings that would adversely impact plant safety. The proposed change does not affect the EDG's ability to ensure that sufficient power is available to supply the safety related equipment required for: 1) the safe shutdown of the facility, and 2) the mitigation and control of accident conditions within the facility. In addition, the proposed change does not affect the EDG's ability to ensure that: 1) the facility can be maintained in a shutdown or refueling condition for extended periods of time, and 2) sufficient instrumentation and control capability is available for monitoring and maintaining the unit status. Therefore, the proposed change does not involve a significant reduction in the margin of safety.

Based on the above evaluation, North Atlantic concludes that the proposed changes do not constitute a significant hazard.

Page 15

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