Text

Proposed Tech Specs,Revising EDG Section to Be Consistent W/ Station Procedures Associated W/Steady State Conditions & W Nuclear Safety Advisory Ltr NSAL 93-022
	ML20236U871
Person / Time
Site:	North Anna
Issue date:	07/28/1998
From:	; VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	;
Shared Package
ML20236U864	List: ML20236U861; ML20236U871;
References
	NUDOCS 9807310127
	Download: ML20236U871 (44)
	v • d • e

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l Attachment 2 Mark-up of Technical Specifications Changes 1

North Anna Power Station Units 1 and 2 Virginia Electric and Power Company I

9907310127 990729

PDR ADOCK 05000338 P PDR

t Unit 1 Mark-up of Technical Specifications Changes b

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, 8-22-86 ILECTRICE POWER SYSTEMS i

SURVEILLANCE REQUIREMENTS

( 4.8.1.1.1 Each of the above required physically independent circuits between the offsite transmission network and the onsite Class IE distribution system shall be:

a. Determined OPERABLE at least once per 7 days by verifying correct breakeer alignment indicating power availability.

[ b. Demor.strated OPERABLE at least once per 18 months during shutdown by manually transferring the onsite Class 1E power supply from the normal circuit to the alternate circuit.

I i 4.8.1.1.2 Each diesel generator shall be demonstrated OPERABLE:

a. In accordance with the frequency specified in Table 4.8.2 on a STAGCERED TEST !! ASIS by:

1. Verifying the fuel level in the day tank.

! 2. Verifying the fuel level in the fuel storage tank.

3. Verifying the fuel transfer pump can be started and transfers fuel from the storage system to the day tank. g

. rate

4. Verifying the diese_1 generator can start ** and gradually accelerate rto eivnehron=<i= sneaaftvuu -romie witn x.-raton m l voltage and frequency at 4160 t 420 volts and 60 t G Al Hz . g5 Subsequently, verifying the generator is synchronized.

( gradually loaded ** to an indicated 2500-2600 KW*** and operates I for at least 60 minutes.

5. Verifying the diesel generator is aligned to provide standby l power to the associated emergency busses.

b. At least once per 92 days by verifying that a sample of diesel fuel from the fuel storage tank is within the acceptable limits specified in Table 1 of ASTM D975-74 when checked for viscosity, water and sediment.

! **This test sha?l be conducted in accordance with the manufacturer's

. recommendations regarding engine prelube and warmuy procedures, and as j applicable regarding loading recommendations.

l f' ***This band is meant as guidance to avoid routine overloading of the engine.

l Loads in excess of this band for special e:. sting under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

NORTH ANNA- UNIT 1 3/4 8-3 Amendment No. 83 L-__---____---_--_---_____-----_--_--___----_-_--_----.---_-------.-----------.---------------_ _ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

. Y 07-18-94 FT FCTRICAL POWER SYSTEMS {

i SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued) wk;$fff sme[,f,7&doae l

.we r w e em I so 59.w* e 5

c. Atleast once per 184 day diesel generator shall be started" and necclemtea t i muo t least#00 mmlin less than or equal to 10 seconds The genemtorfvoltage andta c t frequencyshallbe4160 420 oltsan 601 zenmm urseconos arte.rtne stan si The generator shallbe an y synchronized to its appropriate emergency bas, gradually loaded ** to an indicated 2500 to 2600 kw"*, and operated for at least 60 minutes. The diesel generator shall be started for this test by using one of the following signals on a rotating test basis:

a) Simulated loss of offsite power by itself.

b) Simulated loss of offsite power in conjunction with an ESF actuation test signal.

c) An ESF actuation test signal by itself.

This test, ifit is performed so it coincides with the testing required by Surveillance l Requirement 4.8.1.1.2.a.4, may also serve to concurrently meet those requireme.nts !

as well.

d. At least once per 18 months during shutdown by:

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. ' rge, go..qre~ms uW, m e, we

2. Verifying @ on rejection of a load of reater than or equal to e10 kw se Th voltage and frequency aretnamtared wit @4160 i 420 volts and 60 i Hz. o.s M

. 3. Verifying that the load sequencing timers are OPERABLE with times within the tolerances shown in Table 4.8-1.

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" This test shall be conducted in accordance with the manufacturer's recommendations regartling engine prelube and warmup procedures, and as applicable regarding loading l recommendations. !

"* This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for special testing under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

I NORTH ANNA - UNIT 1 3/4 8-3a Amendment No. 33.184 i i

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, 3-n-n l ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued) 4 Simulating a loss of offsite power by itself, and:

a) Verifying de-energization of the emergency busses and load shedding from the emergency busses, b) Verifying the diesel starts ** on the auto-start signal,

energizes the emergency busses with permanently connected loads within 10 seconds, energizes the auto-connected shutdown loads through the sequencing timers and operates for greater than or equal to 5 minutes while its generator is loaded with the shutdown loads. After energization of these loads, the steady state voltage and fr be maintained at 4160 + 420 voltsand60+(.eguencyshallC&

5. Verifying that on an ESF actuation test signal (without loss of offsite power) the diesel generat9r starts ** cn the auto-start p signal and operates on standby for creater t kn or ecual to @

- 5 minutesf. da" eve altM e er e= =

n se ta N w t*~4 m

, cre4ue-c.1 e reater % u em pso.r urwn*.htueredra..() i ruk sw., 6. Simulating a loss of offsite power in conjunction with an ESF 4

veltgee4 actuation test signal, and j

'll(,oi420ad I 3re4 3r,fc. a) Verifying de-energization of the emergency busses and load 4.fna<g of shedding from the emergency busses.

6020.5he)b)Verifying the diesel starts ** cn the auto start signal, ;

energizes the emergency busses with permanently connected i loads within 10 seconds, energizes the auto-connected '

emergency (accident) loads through the sequencirig timers and operates for greater than or equal to 5 minutss and ;

maintains the steady state voltage and fret;uency at t

= I 4160 + 420 volts and 60 + Q Hz.

c) Verifying that all diesel generator trips, except engine i overspeed, generator differential and breaker overcurrent are automatically bypassed upon loss of voltage on the l

emergency bus and/or a safety injection actuation signal. '

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- This test shall be conducted in accordancar with the rianufacturer's I recosmnendations regarding engine prelube and warmup procedures, and {

as applicable regarding loading recosunendations, l

I NORTH ANNA - UNIT 1 3/4 8-3b Amendment No. 83 l

07-18-94 L

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FIFCTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS*

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4.8.1.1.2 (Continued) l 1-l 7. Verifying the diesel ';nerator F operates ** for at least 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . Dunng the l first 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of this est, the diesel generator shall be loaded to an indicated target value of 29',0 kw (between 2900-3000 kw)*** and during the l

l remaining 2%ours of this test, the diesel generator shall be loaded to an indicated 2500 to 2600 kw*". ]

8. Verifying that the auto-cormected loads to each diesel generator do not exceed the 2000 hour0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months radng of 3000 kw.

9. Verifying the diesel generator's capability to:

a) Synchronize witn the offnite power source while the generator is loaded with its emergency loads upon a simulated restoration of offsite power, l b) Transfer its loads to the offsite power source, and q c) Proceed through ha shutdown sequence. l

10. Verifying that the following diesel generator lockout features prevent diesel ]

generatar startmg only when required, a) Remote Local Selection Switch i l

b) Emergency Stop Switeb ]

Verifying the die::el generator's hot restart capability by: i 11.

a) Openting the diesel generator" leaded to an indicated 2500 to 2600 kw*" for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months or until operating temperatums have stabilized. and h hLWithin 5 minutes of shutdown verify the diesel generator can ie hw rQstarted" andblerm en ar i,=v900 rnnWn less than or equal to 10 (gf,'ygg'p$,

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f .ond& Th crerator voltage and frequency shall be 41601420 volts d 60 - zsJmn in -nna arterihrstart signapg

%W/'~ e o.s (newwC - '

e. lXt least once r 1 years or af ter any m teations which could affect diesel generator intenlependence by starting ** both diesel generators simultaneously, dusing shutduwn, and verifying that both diesel generatorsarceelerate.crat least 900) h@ less than or equal to 10 seconds. gm sn.,f s, m.m ~.%pc l., .,,cr w L 4He a er eque.14o ~5%0 ul45 a.,www" w a mq,i eque 4 5% S Y

- This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and warmup procedures, and as applicable regardin.: loading recommendations. i

" This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for specud testing under direct monitoring of the manufacturer or mornentary

' vatutions due to changing bus loads shall not invalidate the test. !

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Amendment No. 43r446,184 NORTH ANNA - UNIT 1 3/4 8 3c l

MORE RESTRICTIVE CHANGES (M) l 1

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The current Technical Specification (CTS) surveillance requirement (SR) I 4.8.1.1.2 a.4 requires each diesel generator (EDG) to be demonstrated !

OPERABLE by verification that the EDG can start and gradually accelerate ta synchronous speed (900 rpm). The EDG must maintain a generator voltage of 4160 420 volts ano a frequency of 60 1.2 Hertz. In addition, the SR requires

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the verification that each EDG is capable of being synchronized and gradually loaded to an indicate d 2500 - 2600 kW and operates for at least 60 ininutes. The proposed change will state the steady state frequency range as 60 0.5 Henz and i will eliminae the reference to the synchronous speed of 900 rpm. !

I CTS SR 4.8.1.1.2 c. requires at least once per 184 days that each EDG will be

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demonstrated OPERABLE by starting and accelerating to 900 rpm in s 10 !

cconds. 'I he EDG voltage and frequency limits for this start are 4160 40 volts and 60 i 1.2 Hertz. The EDG is then required to be synchronized to the emergency bus, gradually loaded to an indicated 2500 to 2600 kW, and operated for at least 60 minutes. The proposed change will limit the EDG's steady state frequency to 60 0.5 Hertz. Additional changes to this requirement are addressed in the less restrictive change.

1 CTS SR 4.8.1.1.2 d.2 requires each EDG to be demonstrated OPERABLE at !rast l once every 18 months during shutdown by verification that each machine cau j reject a load of 610 kW without approaching an overspeed trip condition. The i EDG is required to maintain a generator voltage of 4160 420 volts and a

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frequency of 60 1.2 Henz during the transient. The proposed change will limi' '

the steady state frequency range to 60 0.5 Hertz. Additional changes to this requirement are addressed in the less restrictive change.

CTS SR 4.8.1.1.2 d.4 b) requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that the EDG can start on a simulated loss of offsite power. The EDG is required to stan and energizes the emergency buses with all permanently connected loads within 10 seconas, energizes the auto-connected shutdown loads through the sequencing times, and oiarates for 2 5 minutes. The EDG is required to maintain a generator steady state voltage of 4160 i 420 volts and steady state frequency of 60 1.2 Hertz. The proposed change will limit the steady state frequency range to 60 i i 0.5 Hertz.

CTS SR 4.8.1.1.2 d.5 requires each EDG to be demonstrated OPERABLE at least

once every 18 months during shutdown by verification that on an ESF actuation l test signt.1 the EDG starts on an auto stan signal and operates for 2 5 minutes. The proposed change modifies the 10 seconds stan requirements for voltage and frequency. The voltage is required to be 2 3960 volts and the frequency is k 59.5 l

H:nz. After the EDG reaches steady state, voltage is required to be 4160 420 l

,, and frequency is limited to 60 0.5 Hertz.

, CTS SR 4.8.1.1.2 d.6 requires each EDG to be demonstrated OPERABLE at least l once every 18 months during shutdown by verification that the EDG can start on a

( simulated loss of offsite p.?wer in conjunction with an ESF actuation test signal.

The EDG is required to start and energizes the emergency buses with al; permanently connected loads within 10 seconds, energizes the auto-connected shutdown loads through the sequencing times, and operates for 2 5 minutes. The EDG is required to maintain a generator steady state voltage of 4160 420 volts and steady state frequency of 60 1.2 Hertz. The proposed change will limit the steady state f equency range to 60 0.5 Hertz.

These changes are acceptable because the safety analyses assumptions for emergency power limits the frequency variations to 60 i 0.5 He.ttz. The safety analyses assume the 4160 AC electrical power frequency to the emergency buses remains relatively constant to the required equipment for the mitigation of e.n analyzed event. The ESF pump's motors are assumed to be supplied with no less than 59.5 Hertz and 3740 vohs of electrical power for the steacy state operation on the emergency buses. This ensures that the ESF pumps will supply the minimum flow necessary to maintain the fuel within the required parameters to prevent degradation. Tec rninimum voltage and frequency requirements for the .

10-second start of the EDO are acceptable becaus e these set the minimum requirements for the required operating range for the emergency buses. The EDG's output breaker is required to close and energize tne permanently connected loads within the 10 seconds limit. The minimum frequency is set by the requirement for steady state operation for the required safety equipment. These .

changes are designated as more restrictive because the limit of frequency variations has decreased from 1.2 to 0.5 Henz.

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LESS RESTRICTIVE CHANGES (L)

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, CTS SR 4.8.1.1.2 c. requires at least once per 184 days that each EDG will be j l

demonstrated OPERABLE by starting and accelerating to 900 rpm in s 10 seconds. Tite EDG voltage and frequency limits for this stan are 4160 420 volts and 60 1.2 Hertz. The EDG is then required to be synchmnized to the emergency bus, gradually loaded to an indicated 2500 to 2600 kW. and operated for at least 60 minutes. The proposed change modifies the 10 sconds stan requirements for voltage end frequency. The voltage is required to be 2 3960 volts and the frequency is 2 59.5 Henz within 10 seconds. After the EDG reaches steady state, voltage is required to be 4160 420 and frequency is limited to 60 0.5 Hertz. The change will also eliminate the reference to the synchronous cpeed of 900 rpm and the requirement to achieve the voltage and )

frequency bands within the 10-second limit.

CTS SR 4.8.1.1.2 d.2 requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that the EDG can reject a load of 610 kW. The EDG is required to maintain a generator voltage of 4160 420 volts and a frequency of 60 i 1.2 Hertz during the transient. The proposed change modifies the requirement to permit the EDG frequency to be maintained less than 66 Henz during the transient and allows three seconds for the steady state voltage and freqtiency to stabilize after the load rejection. Additional changes to this requirement are addressed in the more restrictive change.

CTS SR 4.8.1.1.2 d.11 b) requires each FDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that the EDG can start after it has operated for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months or un:il operating temperatures have stabilized. The stan and acceleration to at least 900 rpm is required within 10 seconds, and the voltage and frequency requirements are specified as 4160 420 volts and 60 i 1.2 Henz. The proposed change modifies the 10 seconds start requirements for voltage and frequency. The voltage is required to be 2 3960 volts and the frequency is 2 39.5 Henz and will eliminate the reference to the synchronous speed of 900 rpm. After the EDG reaches steady state, voltage is .

required to be 4160 420. The change will also eliminate the requirement to L achieve the voltage and frequency bands within the 10-second limit. The steady state frequency change to this requirement is addressed in the more restrictive change.

CTS SR 4.8.1.1.2 e requires both EDGs at least once every 10 years or after any modifications which could affect EDG interdependence by starting both EDGs simultaneously during shutdown. Each EDG is required to stan and acceleration to at least 900 rpm is required within 10 seconds. The proposed change modifies the 10 seconds start requirements for voltage and frequency and will eliminate the l

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reference to the synchronous speed of 900 rpm. The voltage is required to be 2

,, 3960 vohs and the frequeng is 2 59.5 Hertz within 10 second of the start signal.

l. These changes are acceptable because the safety analyses assumes that the EDG l supplies the emerpacy bus with the minimum electrical power within 10 seconds l: of receiving an emergency start signal. During this time, the EDG is required to lJ achiew a specified value for voltage. After an emergency start and with no electricrJ power applied to the emergency bus, the EDG output breaker will close when the EDG's output reaches 95% of rated voltage. The minimum frequency requirement is based on the steady sta.te limit for the EDG assumed in the safety analyses. The EDG supplies the electrical power for the required equipment to mitigate the consequences of design basis events. The 10 seconds start requirement for the EDG ensures electrical power is available for required E equipment to initiate their required functions. Slight variations in voltage and l; frequency of the EDG, for a short period of time, have no impact on the safety analyses assumptions for the mitigation of design basis accidents. The elimination for achievmg the steady state voltage and frequency, within 10-seconds does not affect the safety analyses assumptions for the required ECCS system electrical power requirements. All changes are consistent with the requirements as specified in NUREG-1431 (Rev.1), as amended by the NRC L approved change (TSTF-163 Rev. 2). These changes are designated as less l restrictive because the limits of voltage and frequency for the 10-second start and ll the requirement for steady state voltage and frequency for the EDGs current l: . requirements have been modified.

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01-17 j 3LO FT FCTRICAL POWER SYSTEMS BASES 3/4.8.1 and 3/4.8.2 A.C. and D.C. POWER SOURN AND DISTRIBUTION The OPERABILITY of the A.C. and D.C. power somces and associated distribution systems during operation ensures that sufficient power will be 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. The minimum specified independent and redundant A.C. ,

and D.C. power sources and distribution systems satisfy the requirements of General Design Criteria 17 of Appendix "A" to 10 CFR 50.

For each EDG, the fuel oil transfer system shall be capable of automatically transferring i

j. fuel oil to the associated EDG day tank in sufficient quantities to maintain adequate day tank level to support full load operation of the EDG.

l The ACTION requirements specified for the levels of degradation of the power sources l provide restriction upon continued facility operation commensurate with the level of degradation.

l The OPERABILITY c,f the power sources are consistent with the initial condition assumptions of 1 l the accident analyses and are based upon maintaining at least one of each of the onsite A.C. and D.C. power sources and associated distribution systems OPERABLE during accident conditions coincident with an assumed loss of offsite power and single failure of the other onsite A.C. source.

! The ACTION requirements specified in Modes 5 and 6 address the condition where

sufficient power is unavailable to recover from postulated events (i.e., fuel handling accident).

l Implementation of the ACTION requirements shall not preclude completion of actions to establish a safe conservative plant condition. Completion of the requirements will prevent the occurrence

[ of postulated events for which mitigating actions would be required.

l The OPERABILITY of the minimum specified A.C. and D.C. power sources and associated distribution systems during shutdown and refueling ensures that 1) the facility can be 1 l maintained in the shutdown or refueling condition for extended time periods,2) sufficient

! instrumentation and control capability is available for monitoring and maintaining the unit status, l and 3) sufficient power is available for systems necessary to recover from postulated events in I

these MODES, e.g., the control room emergency ventilation system fans during a fuel handling i accident.

l' The Surveillance Requirements for demonstrating the OPERABILITY of the diesci generators are in accordance with the recommendations of Regulatory Guide 1.9 " Selection of Diesel Generator Set Capacity for Standby Power Supplies," March 10,1971, and 1.108 " Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nu: lear Power Plants" Revision 1, August 1977, as modified by Amendment No. 83 issued August 22,1986.

m / NSEETH NORTH ANNA - UNfT 1 B 3/4 8-1 Amendment No. 82,97. '56 '9?,

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t Technical Specification Bases 3/4.8 Insert The testing of the largest post-accident load rejection in Surveillance Requirement (SR) 4.8.1.1.2 d.2, for demonstra:ing the OPERABILITY of the EDGs,is in accordance with l Lim testing recommendations of Regulatory Guide 1.9, Revision 1. Section C.5.

l The EDG testing in SRs 4.8.1.1.2 c,4.8.1.1.2 d.5,4.8.1.1.2 d.11.b), and 4.8.1.1.2 e separate the start requirements for voltage and frequency from the steady state limits.

The 10-second start requires the EDG to meet the minimum values for voltage and frequency. The EDG's voltage must exceed the 95% value of rated voltage in order for the output breaker to automatically close. The minimum frequency requirement is based on the safety analyses assumption for steady state frequency. The steady state voltage and frequency limits are not required to be maintained during the 10-second stan requirement. Following the fast start of the EDG, the time ta reach steady state voltage and frequency will be periodically monitored in the performance tests. The tests can be used to identify degradation of the governor and voltage regulator performance. The EDG is unloaded in some portions of these surveillance tests and short-term variations in voltage and frequency, outside the steady state lim:t may occur in this condition. The safety analyses assume the steady state electrical power requirements for voltage and frequency to the ECCS equipment is 4160 420 volts and 60 0.5Ilz.

In lieu of actual accident loading demonstration during the performance of SRs 4.8.1.1.2 d.4 and d.6, the EDGs are allowed to supply the required loads by a combination of evolutions. This testing may include a series of sequential, overlapping, or total steps so that the entire connection and loading sequence is verified. This method of testing adequately verifies the capability of each EDG system to energize the emergency bus and supply the power necessary fbr the required safety equipment to mitigate analyzed events.

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. . Justification for Bases Additions Paragraph one is added to provide a reference to the testing requirements of the Regulatory Guide 1.9. The construction of the surveillance is modeled after NUREG.

1431 surveillance requirement 3.8.1.9. The NUREG provides the form of the requirement to comn!" with Regulator Guide recommendation.

Paragraph two provides for the division of the EDG starting requirements for voltage and frequency and the steady state requirements for the parameters. NUREG-1431 Rev. I has been modified by TSTF-163 Revision 2, and approved by the NRC on 4/16/98. This i changes the NUREG-1431 requirements for testing of the EDO. The improved Technical Specifications (ITS) surveillance requirements (SRs) relate to the current Technical Specification (CTS) SRs: ITS SR 3.8.1.7(CTS 4.8.1.1.2 c), ITS SR 3.8.1.12 (CTS 4.8.1.1.2 d.5), ITS SR 3.8.1.15(CTS 4.8.1.1.2 d.11), and ITS SR 3.8.1.20 (CTS 4.8.1.1.2 e).. Steady state limits for voltage and frequency will continue to be defined by the Technical Specifications, but the time required to reach steady state voltage and I

frequency will be periodically monitored in the testing procedures.

Paragraph three is developed from NUREG-1431 Bases for the ITS SRs 3.8.1.12 (EDG start on an ESF signal) and 3.8.1.19 (EDG start on an ESF coincident with a loss of offsite power). The NUREG Bases statements describe how the required testing may be conducted in a " series of sequential, overlapping, or total steps so the entire connection and loading sequence is verified."

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i Unit 2 Mark-up of Technical Specifications Changee l

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4-25-85 ELECTRICAL POWER SYS"IEMS SURVEILLANCE REQUIREMENTS 4.8.1,1.1 Each of the above mquimd physically independent circuits between the offsite l )

transmission network and the onsite Class 1E distribution system shall be:

a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignment indicating power availability.

b. Demonstrated OPERABLE at least once per 18 months during shutdown by I manully transfening the onsite Class IE power supply from the normal circuit to the attemate circuit.

4.8.1.1.2 Each diesel generator shall be demonstrated OPERABLE: l

a. In accordance with the frequency specified in Table 4.8.2 on a STAGGERED j TEST BASIS by: i

1. Verifying the fuel levelin the day tank.

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2. Verifying the fuellevelin the fuel storage tank.

3. Verifying the fuel transfer pump can be started and transfers fuel from the stosage system to the day tank.

4. Verifying the diesel generatcr can start ** and gradually accelerate to G. nuAC Oynchronouew (900 =dM with e = =soltage and frequency at Y** i __ 41601420 volts and 60 i QHz. Subsequently, verifying the generator is y synchronized, gradually loaded" to an indicated 2500-2600 kW* and operates for a least 60 minutes.

5. Verifying the diesci generatar is aligned to provide standby power to the associated emergency busses.

b. At least once per 92 days by verifying that a sample of diesel fuel from the fuel storage tank obtained as a DRAIN sample in accordance with ASTM-D270-65,is within the acceptable limits specified in Table 1 of ASTM D975-74 when checked for viscosity, water and sediment.

/(4D,oW L..% 7e,/,T..Q. +E, n ."1- %tG "*7/'$"4***

c. Atleast once per 184 day dieselgenerator shalltic started ** and~au.au.secr to) _

I (5tleast400 rpmMn less than or equal to 10 w=4 The generatortvoitage and g )

fmquency shall be 41601420 volts and 60i Hz(witnm ueaonos =um me n-n ,

M c s-9 $ l Tnis test shall be conducted in accordance with the manufacturer's recommendations I regarding engine prelube and warmup pmcedures, and as applicable regartling loading ;

recommendations.

- - This band is meant as guidance to avoid routine overloading of the engine. l.oads in excess of this band for special testing under ducct monitoring of the manufacturer or monientary variations due to changing bus loads shall not invalidate the test.

NORTH ANNA - UNIT 2 3/48-3 Amendment No. 48

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07-18-92 ELECTRICAL POWER SYSTEMS

. . SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued)

The generator shall be manually synchronized to its appropriate emergency bus.

gradually loaded" to at .ndicated 2500 to 2600 kw***, and operated for at least

! 60 minutes. The diesel generator shall be started for this test by using one of the following signals on a rotating test basis:

a) Simulated loss of offsite power by itself.

b) Simulated loss of offsite power in conjunction with an ESF actuation test signal.

c) An ESF actuation test signal by itself. \.

This test, ifit is performed so it coincides with the testing required by Surveillance Requirement 4.8.1.1.2.a.4, may also serve to concurrently meet those requirements as well.

d. At least once per 18 months during shutdown by: s

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.

{g'g;f*yje55,g,j] (

2. Verifying @f, on rejection of a loadpf greater than or equal to 610 kwTthe g volta e and f uency are(manfinined4vitS)4160 420 volts and 60 Hz. o,r m

3. Verifying that the load sequencing timers are OPERABLE with times within the tolerances shown in Table 4.8-1.

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4. Simulating a loss of offsite power by itself, and:

a) Verifying de-energization of the emergency busses and load shedding from the emergency busses.

b) Verifying the diesel starts" on the auto-start signal, energizes the emergency busses with permanently connected loads within 10 seconds, energizes the auto-connected shutdown loads through the sequencing timers and operates for greater than or equal to 5 minutes while its generatoris loaded with the shutdown loads. After energization of these loads, the steady state voltage and frequency shall be maintained at 41601420 volts and 60i . Hz.

o.5 b1 This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

" This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for special testing under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

NORTH ANNA - UNIT 2 3/4 8-4 Amendment No. 70,165

07-18-9-1 FT FPTRICAL K)WER SYS" EMS i

SURVEILLANCE REQUIREMENTS

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4.8.1d.2 (Conu.nued) aaam <,H.,e g<uk w)h* m

a,aLa rs% cr elOsnamdse dw ,4ser h ,y

59.s*

5. Venfymg that on an ESF actuation test signal (without loss of power) the A diesel generator starts ** on the auto-start s' an oerates on standby for-greater than or equal to 5 minute fpghQ*$#f,gofff}

6. Simulatmg a loss of offsite power m conjunction with an ESF actuation test

' signal, and a) Verifying de-energization of the emergency busses and load shedding from the emergency busses.

b) Verifying the diesel starts" 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 l sequencing timers and operates for greater than or equal to 5 minutes

! and maintains the stead state voltage and frequency at 41601420 volts and 60 Hz. og m c) Verifying that all diesel generator trips, except engine overspeed, generator differential and breaker overcurrent are automatically bypassed upon loss of voltage on the emergency bus and/or a safety injection actuation signal.

7. Verifying the diesel generator operates ** for at least 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . During the first 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of this test, the diesel generator shall be loaded to an indicated i target value of 2950 kw (between 2900-3000 kw)"* and during the remaining 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months of this test, the diesel generator shall be loaded to an l )

indicated 2500 to 2600 kw"*. l l 8. Verifymg that the auto-connected loads to each diesel generator do not l-exceed the 2000 hour0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months rating of 3000 kw. l l 9. Verifying the diesel generator's capability to:

a) Synchronize with the offsite power source while the generator is loaded with its emergency loads upon a simulated restoration of offsite power, l b) Transfer its loads to she offsite power source, and c) Proceed through its shutdown sequence.

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This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

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"* This band is meant as guidance to avoid routine overloading of the engine. Loads in excess '

of this band for special testing under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

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NORTH ANNA - UNIT 2 3/48-5 Amendment No. 4;L-48,165 1

07-18-94 Et FCTRICAL POWER SYSTEMS

, ,, SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued)

10. Venfymg that the following diesel generator lockout features prevent diesel generator starung only when required:

a) Remote 1 mal Selection Switch b) Emergency Stop Switch

11. Verifying the diesel generator's hot restart capability by:

a) Operating the diesel generator ** loaded to an indicated 2500 to 2600

t. kw"* for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months or until operating temperatures have stabilized. and 4g ) Within 5 minutes of shutdown verify the diesel generator can be f q w ,,, t

- started" &+*1~==<' en at"==' = >menlin less than or equal to 10 Q [ seconds k enerator voltage and frequency shall be 4160 420 volts G].,,P,gy/,,,n,

...n . and 60 Qs.r, s m nr,n.n .,.no,i.

.cm.a,, u _ myie ,:1 g i,n g

e. At least once per 10 years or aYter any momncanons which could affect diesel generator interdependence by staning" both diesel generators simultaneously, during shutdown, and verifying that both diesel generators 0moetFraset6'at lea .

c Min less than or equal to 10 seconds @h,m.'LT.?S,,u'le,',%..'% 1 *F 3/jf;81 i+. rer u

( e,% .c 4.8.1.1.3 Each diesel generator 125-volt battery bank and charger shall be demonstrated OPERABLE:

a. At least once per 7 days by verifying that:

1. The parameters in Table 4.8-3 meet Category A limits and

2. The total battery terminal voltage is 2: 129 volts on a float charge,

b. At least once per 92 days and within 7 days after a t,attery discharge where the l

battery terminal voltage decreased below 110 volts or battery overcharge above 150 volts, by verifying that:

l i i 1. The parameters in Table 4.8-3 meet Category B limits and 1

2. There is no visible corrosion at either tenninals or connectors. or the connection resistance of these items is less than 150 x 10 to the minus )

6 ohms.

" This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

"* This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for special testing under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

NORTH ANNA - UNIT 2 3/48-6 Amendment No. 48r84.165

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MORE RESTRICTIVE CHANGES (M)

'The current Technical Speci'ication (CTS) surveillance requirement (SR) l 4.8.1.1.2 a.4 requires each diesel generator (EDG) to be demonstrated I

L OPERABLE by verification that the EDG can stan and gradually accelerate to l synchronous speed (900 rpm). The EDG must maintain a generator voltage of l 4160 t 420 volts and a frequency of 60 1.2 Hertz. In addition, the SR requires j the verification that each EDG is capable of being synchronized and gradually l loaded to an indicated 2500 - 2600 kW and operates for at least 60 minutes. The proposed change will state the steady state frequency range as 60 0.5 Henz and will eliminate the reference to the synchronous speed of 900 rpm.

l CTS SR 4.8.1.1.2 c. requires at least once per 184 days that each EDG will be demonstrated OPERABLE by staning and accelerating to 900 rpm in s 10 l seconds. The EDG voltage and frequency limits for this start are 4160 420 volts l and 60 i 1.2 Henz. The EDG is then required to be synchronized to the emergency bus, gradually loaded to an indicatee 2500 to 2600 kW, and operated j for at least 60 minutes. The proposed change will limit the EDG's steady state

frequency to 60 t 0.5 Hertz. . Additional changes to this requirement are addressed l in the less restrictive change.

! CTS SR 4.8.1.1.2 d.2 requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that each machine can reject a load of 610 kW without approaching an overspeed trip condition. The l

EDG is required to maintain a generator voltage of 4160 i 420 volts and a l frequency of 60 t 1.2 Hertz during the transient. The proposed change will limit

! the steady state frequency range to 60 t 0.5 Henz. Additional changes to this l

requirement are addressed in the less restrictive change.

l CTS SR 4.8.1.1.2 d 4 b) requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that the EDG can start on a simulated loss of offsite power. The EDG is required to start and energizes the emergency buses with all permanently connected loads within 10 L seconds, energizes the auto-connected shutdown loads through the sequencing times, and operates for 2 5 minutes. The EDG is required to maintain a generator steady state voltage of 4160 i 420 volts and steady state frequency of 60 1.2 l Henz. The proposed change will limit the steady state frequency range to 60 j 0.5 Hertz.

l l CTS SR 4.8.1.1.2 d.5 requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that on an ESF actuation test signal the EDG stans on an auto start signal and operates for 2 5 minutes. The i proposed change modifies the 10 seconds start requirements for voltage and frequency. The voltage is required to be 2 3960 volts and the frequency is 2 59.5 !

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j Hertz. After the EDG reaches steady state, voltage is required to be 4160 420

, and frequency is limited to 60 0.5 Hertz.

CTS SR 4.8.1.1.2 d.6 requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that the EDG can start on a simulated loss of offsite power in conjunction with an ESF actuation test signal.

The EDG is required to start and energizes the emergency buses with all permanently connected loads within 10 seconds, energizes the auto-connected shutdown loads through the sequencing times, and operates for 2 5 minutes. The i

EDG is required to maintain a generator steady state voltage of 4160 420 volts

and steady state frequency of 60 1.2 Hertz. The proposed change will limit the steady state frequency range to 60 t 0.5 Hertz.

These changes are acceptable because the safety analyses assumptions for emergency power limits the frequency variations to 60 i 0.5 Hertz. The safety analyses assume the 4160 AC electrical power frequency to the emergency buses remains relative constant to the required equipment for the mitigation of an analyzed event. The ESF pump's motors are assumed to be supplied with no less than 59.5 Hertz and 3740 volts of electrical power for the steady state operation on the emergency buses. This ensures that the ESF pumps will supply the minimum flow necessaiy to maintain the fuel within the required parameters to prevent degradation. The minimum voltage and frequency requirements for the 10-second start of the EDG are acceptable because these set the minimum requirements for the required operating range for the emergency buses. The EDG's output breaker is required to close and energize the permanently connected loads within the 10 seconds limit. The minimum frequency is set by the requirement for steady state operation for the required safety equipment. These changes are designated as more restrictive because the limit of frequency variations has decreased from 1.2 to 0.5 Hertz.

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LESS RESTRICTIVE CHANGES (L)

CTS SR 4.8.1.1.2 c. requires at least once per 184 days that each EDG will be demonstrated OPERABLE by starting and accelerating to 900 rpm in s 10 seconds. The EDG voltage and frequency limits for this start are 4160 420 volts l and 60 i 1.2 Henz. The EDG is then required to be synchronized to the emergency bus, gradually loaded to an indicated 2500 to 2600 kW, and operated for at least 60 minutes. The proposed change modifies the 10 seconds start requirements for voltage and frequency. The voltage is required to be 2 3960 volts and the frequency is 2 59.5 Hertz within 10 seconds. After the EDG reaches steady state, voltage is required to be 4160 420 and frequency is limited to 60 0.5 Hertz. The change will also eliminate the reference to the synchronous speed of 900 rpm and the requirement to achieve the voltage and frequency bands within the 10-second limit.

CTS SR 4.8.1.1.2 d.2 requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that the EDG can reject a load of 610 kW. The EDG is required to maintain a generator voltage of 4160 420 volts and a frequency of 60 1.2 Hertz during the transient. The proposed change modifies the requirement to permit the EDG frequency to be maintained less than 66 Henz during the transient and allows three seconds for the steady state voltage and frequency to stabilize after the load rejection. Additional changes to this requirement are addressed in the more restrictive change.

CTS SR 4.8.1.1.2 d.11 b) requires each EDG to be demonstrated OPERABLE at least once every 18 months during shutdown by verification that the EDG can start after it has operated for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months or until operating temperatures have stabilized. The stan and acceleration to at least 900 rpm is required within 10 seconds. and the voltage and frequency requirements are specified as 4160 420 volts and 60 i 1.2 Hertz. The proposed change modifies the 10 seconds start requirements for voltage and frequency. The voltage is required to be 2 3960 volts and the frequency is 2 59.5 Hertz and will eliminate the reference to the synchronous speed of 900 rpm. After the EDG reaches steady state, voltage is required to be 4160 420. he change will also eliminate the requirement to achieve the voltage and frequency bands within the 10-second limit. The steady state frequency change to this requirement is addressed in the more restrictive change.

CTS SR 4.8.1.1.2 e requires both EDGs at least once every 10 years or after any modifications which could affect EDG interdependence by starting both EDGs simultaneously during shutdown. Each EDG is required to stan and acceleration to at least 900 rpm is required within 10 seconds. The proposed change modifies the 10 seconds stan requirements for voltage end frequency and will eliminate the

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( reference to the synchronous speed of 900 rpm. The voltage is required to be 2

. 3960 volts and the frequency is 2 59.5 Hertz within 10 second of the start signal.

l These changes are acceptable because the safety analyses assumes that the EDG l supplies the emergency bus with the minim.a electrical power within 10 seconds l of receiving an emergency start signal. During this time, the EDG is required to l achieve a specified value for voltage. After an emergency start and with no electrical power applied to the emergency bus, the EDO output breaker will close l when the EDG's output reaches 95% of rated voltage. The minimum frequency requirement is based on the steady state limit for the EDG assumed in the safety l analyses. The EDG supplies the electrical power for the required equipment :o mitigate the consequences of design basis events. The 10 seconds start requirement for the EDG ensures electrical power is available for required l equipment to initiate their required functions. Slight variations in voltage and frequency of the EDG, for a short period of time, have no impact on the safety analyses assumptions for the mitigation of design basis accidents. The elimination for achieving the steady state voltage and frequency, within 10-seconds does not affect the safety analyses assumptions for the required ECCS system electrical power requirements. All changes are consistent with the requirements as specified m NUREG-1431 (Rev.1), as amended by the NRC approved change (TSTF-163 Rev. 2). These changes are designated as less restrictive because the limits of voltage and frequency for the 10-second start and the requirement for steady state voltage and frequency for the EDGs current requirements have been modified.

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, 01-17-97

}f.g A FCTRICAL POWER SYSTEMS

! BASES 1

3/4.8.1 and 3/4.8.2 A.C. and D.C. POWER SOURrM AND DISTRIBUTION l

The OPERABILITY of the A.C. and D.C. power sources and associated distribution systems during operation ensures that sufficient power will be 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. The minimum specified independent and redundant A.C.

and D C. power sources and distribution systems satisfy the requirements of General Design .

Criteria 17 of Appendix "A" to 10 CFR 50.

For each EDG, the fuel oil transfer system shall be capable of automatically transferring l fuel oil to the associated EDG day tank in sufficient quantities to maintain adequate day tank level l to support full load operation of the EDO.

The ACTION requirements specified for the levels of degradation of the power sources l provide restriction upon continued facility operation commensurate with the level of degradation.

The OPERABILITY of the power sources are consistent with the initial condition assumptions of the accident analyses and are based upon maintaining at least one of each of the onsite A.C. and D.C. power sources and associated distribution systems OPERABLE during accident conditions I coincident with an assumed loss of offsite power and single failure of the other onsite A.C. source.

The ACTION requireraents specified in Modes 5 and 6 address the condition where l sufficient power is unavailable to recover from postulated events (i.e., fuel handling accident).

l Implementation of the ACTION requirements shall not preclude completion of actions to establish a safe conservative plant condition. Completion of the requirements will prevent the occurrence i of postulated events for which mitigating actions would be required.

The OPERABILITY of the minimum specified A.C. and D.C. power sources and associated distribution systems during shutdown and refueling ensures that 1) the facility can be maintained in the shutdown or refueling condition for extended time periods,2) sufficient instrumentation and control capability is available for monitoring and maintaining the unit status, and 3) sufficient power is available for systems necessary to recover from postulated events in these . MODES, e.g., the control room emergency ventilation system fans during a fuel handling accident The Surveillance Requirements for demonstrating the OPERABILITY of the diese!

generators are in accordance with the recommendations of Regulatory Guide 1.9 " Selection of Diesel Generator Set Capacity forStandby Power Supplies,*' March 10,-1971, and 1.108 " Periodic

Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants" Revision 1. August 1977, as modified by Amendment No. 48 issued August 22,1986.

(J O SC- r Th f NORTH ANNA - UNIT 2 ~ B 3/4 8-1 Amendment No. 4S. Et !3S. '79.

184 I

t Technical Specification Bases 3/4.8

/ Insert i

The testing of the largest post-accident load rejection in Surveillance Requirement (SR) 4.8.1.1.2 d.2, for demonstrating the OPERABILITY of the EDGs, is in accordance with i l the testing recommendations of Regulatory Guide 1.9, Revision 1, Section C.5.

l The EDG testing in SRs 4.8.1.1.2 e,4.8.1.1.2 d.5,4.8.1.1.2 d.11.b), and 4.8.1.1.2 e separate the start requirements for voltage and frequency from the steady state limits.

The 10-secorid start requires the EDG to meet the minimum values for voltage and l frequency. The EDG's voltage must exceed the 95% value of rated voltage in order for the output breaker to automatically close. The minimum frequency requirement is based on the safety analyses assumption for steady state frequency. The steady state voltage l and frequency limits are not required to be maintained during the 10-second start requirement. Following the fast start of the EDG, the time to reach steady state voltage l and frequency will be periodically monitored in the performance tests. The tests can be I

used to identify degradation of the governor and voltage regulator performance. The l EDG is unloaded in some portions of these surveillance tests and short-term variations in l voltage and frequency, outside the steady state limit may occur in this condition. The

! safety analyses assume the steady state electrical power requirements for voltage and frequency to the ECCS equipment is 4160 i 420 volts and 60 0.5 Hz.

In lieu of actual accident loading demonstration during the performance of SRs 4.8.1.1.2 d.4 and d.6, the EDGs are allowed to supply the required loads by a combination of evolutions. This testing may include a series of sequential, overlapping, or total steps so l that the entire connection and loading sequence is verified. This method of testing adequately verifies the capability of each EDG system to energize the emergency bus and supply the power necessary for the required safety equipment to mitigate analyzed events.

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. Justification for Bases Additions Paragraph one is added to provide a reference to the testing requirements of the Regulatory Guide 1.9. The construction of the surveillance is modeled after NUREG-l 1431 surveillance requirement 3.8.1.9. The NUREG provides the form of the requirement to comply with Regulator Guide recommendation.

Partgraph two provides for the division of the EDG starting requirements for voltage and frequency and the steady state requirements for the parameters. NUREG-1431 Rev. I has been modified by TSTF-163 Revision 2, and approved by the NRC on 4/16/98. This changes the NUREG-1431 requirements for testing of the EDG. The improved Technical Specifications (ITS) surveillance requirements (SRs) relate to the current Technical Specification (CTS) SRs: ITS SR 3.8.1.7(CTS 4.8.1.1.2 c). ITS SR 3.8.1.12 (CTS 4.8.1.1.2 d.5), ITS SR 3.8.1.15(CTS 4.8.1.1.2 d.11), and ITS SR 3.8.1.20 (CTS 4.8.1.1.2 e). Steady state limits for voltage and frequency will continue to be defined by the Technical Specifications, but the time required to reach steady state voltage and frequency will be periodically monitored in the testing procedures.

Paragraph three is developed from NUREG-1431 Bases for the ITS SRs 3.8.1.12 (EDG start on an ESF signal) and 3.8.1.19 (EDG start on an ESF coincident with a loss of offsite power). The NUREG Bases statements describe how the required testing may be conducted in a " series of sequential, overlapping, or total steps so the entire connection and loading sequence is verified."

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Attachment 3 Proposed Technical Specifications Changes i

1 North Anna Power Station Units 1 and 2 )

Virginia Electric and Power Company Attachment 2 )

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Unit 1 Proposed Technical Specifications Changes I

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l ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS l 4.8.1.1.1 Each of the above required physically independent circuits between the offsite transmission network and the onsite Class lE distribution system shall be:

a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignment indicating power availability.

b. Demonstrated OPERABLE at least once per 18 months during shutdown by manually transferring the onsite Class IE power sunply from the normal circuit to the alternate circuit.

4.8.1.1.2 Each diesel generator shall be demonstrated OPERABLE:

a. In accordance with the frequency specified in Table 4.8-2 on a STAGGERED TEST BASIS by:

1. Verifying the fuel level in the day tank.

2. Verifying the fuellevelin the fuel storage tank.

3. Verifying the fuel transfer pump can be started and transfers fuel from the storage system to the day tank.

4. Verifying the diesel generator can start ** and gradually accelerate to a steady state voltage and frequency of 4160 t 420 volts and 60i 0.5 IIz. Subsequently, verifying the generator is synchronized, gradually loaded ** to an indicated 2500-2600 kW*** and operates for a least 60 minutes.

5. Verifying the diesel generator is aligned to provide standby power to the associated emerger.cy busses.

b. At least once per 92 (ays by verifying that a sample of diesel fuel from the fuel storage tank is withi i the acceptable limits specified in Table 1 of ASTM D975-74 when checked for s iscosity, water and sediment.

This test shall be conducted in accordance with the manufacturer's recommendations l

regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

- - This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for special testing under direct monitoring of the manufacturer or momentary variations ciae to changing bus loads shall not invalidate the test.

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NORTH ANNA - UNIT 1 3/4 8-3 Amendment No. 83, l

L_____________ _ _ _ _ _ _

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (continued) l i

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c. At least once per 184 days, the diesel generator shall be started ** and in less than or equal to 10 seconds after the start signal and achieve voltage greater than or equal i i

to 3960 volts and frequency greater than or equal to 59.5 Hz. The generator steady j l

state voltage and frequeney shall be 4160i 420 volts and 60 0.5 Hz. The j

generator shall be manually synchronized to its appropriate emergency bus, gradually loaded ** to an indicated 2500 to 2600 kW* **, and operated for at least t 60 minutes. The diesel generator shall be started for this test by using one of the following signals on a rotating test basis:

i a) Simulated loss of offsite power by itself.

J b) Simulated loss of offsite power in conjunction with an ESF actuation test signal. .

c) An ESF actuation test signal by itself.

This test,ifit is performed so it coincides with the testing required by Surveillance Requirement 4.8.1.1.2.a.4, may also serve to concurrently meet those requirements as well.

d. At least once per 18 months during shutdown by:

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, on rejection of a load of greater than or equal to 610 kW, the frequency remains less than or equal to 66 Hz, and within 3 seconds the voltage-and frequency are 4160i420 volts and 60 0.5 Hz.

3. Verifying that the load sequencing timers are OPERABLE with times within the tolerances shown in Table 4.8-1.

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This test shall be conducted in accordance with the manufacturer's recommendations !

regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

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- - This band is meant as guidance to avoid routine overloading of the engine. Loads m excess of this band for special testing under direct monitoring of the manufacturer or momentary ;

variations due to changing bus loads shall not invalidate the test.

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NORTH ANNA - UNIT 1 3/4 8-3a Amendment No. 83,184,

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued)

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4. Simulating a loss of offsite power by itself, and:

a). Verifying de-energization of the emergency busses and load shedding from the emergency busses.

b). Verifying the diesel starts ** on the auto-start signal, energizes the emergency busses with permanently connected loads within 10 seconds, i energizes the auto-connected shutdown loads through the sequencing timers and operates for greater than or equal to 5 minutes while its j generatoris loaded with the shutdown 1 ids. After energizaiion of these !

loads, the steady state voltage and frequency shall be maintained at 4160 {

420 volts and 60 0.5 Hz. l

5. Verifying that on an ESF actuation test signal (without loss of offsite power),

the diesel generator starts *

on the auto-start signal and achieves vohage greater than or equal to 3960 volts and frequency greater than or equal to 59.5 Hz within l 10 seconds and operates on standby for greater than or equal to 5 minutes with I a steady state voltage of 4160i420 volts and steady state frequency of 60i0.5 i Hz.

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6. Simulating a loss of offsite power in conjunction with an ESF actuation test signal, and a). Verifying de-energization of the emergency busses and load shedding from the emergency busses.

b). Verifying the diesel starts ** 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 sequencing timers and operates for greater than or equal to 5 minutes and maintains the steady state voltage and frequency at 4160i420 volts and 60i 0.5 Hz. l c). Verifying that all diesel generator trips, except engine overspeed, generator differential and breaker overcurrent are automatically bypassed upon loss of voltage on the emergency bus and/or a safety injection actuation signal.

l l ** This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

NORTH ANNA-UNIT 1 3/4 8-3b Amendment No.10

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS 4.8.1.1.2 (Continued)

7. Verifying the diesel generator operates ** for at Izast 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . During the first 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of this test, the diesel generator shall be loaded to an indicated target value of 2950 kW (between 2900-3000 kW)*** and during the remaining 22 :

hours of this test, the diesel generator shall be loaded to an indicated 2500-2600 '

kW * * *.

8. Verifying that the auto-connected loads to each diesel generator do not exceed l the 2000 hour0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months rating of 3000 kW. I

9. Verifying the diesel generator's capability to: <

a). Synchronize with the offsite power source while the generator is loaded with its emergency loads upon a simulated restoration of offsite power, b). Transfer its loads to the offsite power source, and c). Proceed through its shutdown sequence.

10. Verifying that the following diesel generator lockout features prevent diesel generator starting only when required:

a). Remote Local Selection Switch b). Emergency Stop Switch

11. Verifying the diesel generator's hot restart capability by:

a). Operating the diesel generator ** loaded to an indicated 2500 to 2600 kW*** for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months or until operating temperatures have stabilized, and b). Within 5 minutes of shutdown verify the diesel generator can be started ** and in less than or equal to 10 seconds of the start signal with voltage greater than or equal to 3960 volts and frequency greater than or equal to 59.5 Hz. The steady state generator voltage and frequency shall be 4160 420 volts and 60 i 0.5 Hz.

e. 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 start in less than or equal to 10 seconds of the start signal and achieve a voltage greater than or equal to 3960 volts and a frequency greater than or equal to 59.5 Hz.

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- This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

- - This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for special testing under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

. NORTH ANNA - UNIT 1 3/4 8-3c Amendment No. 83,145,184,

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3/4.8 ELECTRICAL POWER SYSTEMS BASES 1

1 3/4.8.1 and 3/4.8.2 A.C. and D.C. POWER SOURCES AND DISTRIBUTION (Continued)

The testing of the largest post-accident load rejection in Surveillance Requirement (SR) 4.8.1 '.2.d.2, for demonstrating the OPERABILITY of the EDGs,is in accordance with the testing recommendations of Regulatory Guide 1.9, Revision 1, Section C.5.

The EDG testing in SRs 4.8.1.1.2.c,4.8.1.1.2.d.5,4.8.1.1.2.d.11.b), and 4.8.1.1.2.e separate the start requirements for voltage and frequency from the steady state limits. The 10-second start requires the EDG to meet the minimum values for voltage and frequency. The EDG's voltage must exceed the 95% value of rated voltage in order for the output breaker to automatically close. The minimum frequency requirement is based on the safety analyses assumption for steady state

! frequency. The steady state voltage and frequency limits are not required to be maintained during the 10-second start requirement. Following the fast start of the EDG, the time te reach steady state voltage and frequency is periodically monitored in the performance tests. The tests can be used to identify deg adation of the governor and voltage regulator performance. The EDG is unloaded in some portions of these surveillance tests and short-term variations in voltage and frequency, outside the steady state limits may occur in this condition. The safety analyses assume the long-l term steady state electrical power requirements for voltage and frequency to the ECCS equipment

! is 4160i 420 volts and 60 0.5llz, In lieu of actual accident loading demonstration during the performance of SRs l

l 4.8.1.1.2.d.4 and 4.8.1.1.2.d.6, the EDGs are allowed to supply the required loads by a combination l of evolutions. This testing may include a series of sequential, overlapping, or total steps so that the entire connection and loading sequence is verified. This method of testing adequately verifies the

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capability of each EDG system to energize the emergency bus and supply the power necessary for j the required safety equipment to mitigate analyzed events.

The Surveillance Requirements for demonstrating the OPERABILITY of the Emergency Diesel Generator batteries and the Station batteries are based on the recommendations of l Regulatory Guide 1.129," Maintenance, Testing and Replacement of Large Lead Storage Batteries j for Nuclear Power Plants," February 1978, and IEEE Std. 450-1980, "IEEE Recommended {

l Practice for Maintenance, Testing and Replacement of Large Lead Storage Batteries for

{

Generating Stations and Substations," as modified by Amendment No. 97 issued March 25,1988. I 1

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l NORTH ANNA - UNIT I B 3/4 8-2 Amendment No. -203, l 1 L____________________------ 1

I Unit 2 Proposed Technical Specifications Changes

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS 4.8.1.1.1 Each of the above required physically independent circuits between the offsite transmission network and the onsite Class lE distribution system shall be:

a. Determined OPERABLE at least once per 7 days by verifying correct breaker alignment indicating power an lability.

b. Demonstrated OPERABLE at least once per 18 months during shutdown by manually transferring the onsite Class 1E power supply from the normal circuit to the alternate circuit.

4.8.1.1.2 Each diesel generator shall be demonstrated OPERABLE:

a. In accordance with the frequency specified in Table 4.8.2 on a STAGGERED TEST BASIS by:

1. Verifying the fuel level in the day tank.

2. Verifying the fuel level in the fuel storage tank.

3. Verifying the fuel transfer pump can be started and transfers fuel from the storage system to the day tank.

4. Verifying the diesel generator can start *

and gradually accelerate to a steady state voltage and frequency of 4160 i 420 volts and 60 i 0.5 Hz. Subsequently, verifying the generator is synchronized, gradually loaded ** to an indicated 2500-2600 kW*** and operates for a least 60 minutes.

5. Verifying the diesel generator is aligned to provide standby power to the associated emergency busses.

b. At least once per 92 days by verifying that a sample of diesel fuel from the fuel storage tank obtained as a DRAIN sample in accordance with ASTM-D270-65, is within the acceptable limits specified in Table 1 of ASTM D975-74 when checked for viscosity, water and sediment.

c. At least once per 184 days, the diesel generator shall be started ** and in less than or i equal to 10 seconds after the start signal and achieve voltage greater than or equal to 3960 volts and frequency greater than or equal to 59.5 Hz. The generator steady state ;

voltage and frequency shall be 4160 420 volts and 60 i 0.5 Hz. The generator shall j be manually synchronized to its appropriate emergency bus, gradually loaded *

to an i i

This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and warmup procedures, and as applicable regarding loading recommendations.

This band is meant as guidance to avoid routine overloading of the engine. Loads in excess )

of this band for special testing under direct monitoring of the manufacturer or momentary i variations due to changing bus loads shall not invalidate the test.

NORTH ANNA - UNIT 2 3/4 8-3 Amendment No. 48, !

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ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS 4.b.l.l.2 (Continued) indicated 2500 to 2600 kW***, and operated for at least 60 minutes. The diesel l

generator shall be st rted for this test by using one of the following signals on a rotating test basis:

a) Simulated loss of offsite power by itself.

b) Simulated loss of offsite power in conjunction with an ESF actuation test signal.

c) An ESF actuation test signal by itself.

This test,ifit is performed so it coincides with the testing required by Surveillance Requirement 4.8.1.1.2.a.4, may also serve to concurrently meet those requirements as well.

d. At least once per 18 months during shutdown by:

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, on rejection of a load of greater than or equal to 610.kW, the frequency remains less than orequal to 66 Hz, and within 3 seconds the voltage and frequency are 4160i420 volts and 60 0.5 Hz.

3. Verifying that the load sequencing timers are OPERABLE with times within the tolerances shown in Table 4.8-1.

4. Simulating a loss of offsite power by itself, and:

a) Verifying de-energization of the emergency busses and load shedding from the emergency busses.

b) Verifying the diesel starts ** on the auto-start signal, energizes the emergency busses with permanently connected loads within 10 seconds, energizes the auto-connected shutdown loads through the sequencing timers and operates for greater than or equal to 5 minutes while its generator is loaded with the shutdown loads. After energization of these loads, the steady state voltage and frequency shall be maintained at 4160 i 420 volts and 60 0.5 Hz.

l This test shall be conducted in accordance with the manufacturer's recommendations regarding engine prelube and wannup procedures, and as applicable regarding loading recommendations.

- - This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for special testing under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

NORTH ANNA - UNIT 2 3/4 8 4 Amendment No. 70,165,

El.ECTRICAL POWER SYSTEMS SU_".VEILLANCE REQUIREMENTS (Continued) 4.8.1.1.2 (Continued)

5. Verifying that on an ESF actuation test signal (without loss of offsite power), the diesel generator starts *

on the auto-start signal and achieves voltage greater than or equal to 3960 volts and frequency greater than or equal to 59.5 llz within 10 seconds and operates on standby for greater than or equal to 5 minutes with a steady state voltage of 4160 420 volts and steady state frequency of 60i0.5 liz.

6. Simulating a loss of offsite power in conjunction with an ESF actuation test signal, and a) Vcrifying de-energization of the emergency busses and load shedding from the emergency busses.

b) Verifying the diesel starts ** on the auto-start signal, energizes the emergency busses with permanently connected !oads within 10 seconds, energizes tl e auto-connected emergency (accident) loads through the sequencing timers and operates for greater than or equal to 5 minutes and maintains the steady state voltage and frequency at 4160 i 420 volts and 60 t 0.5 liz. l c) Verifying that all diesel generator trips, except engine overspeed, generator differential and breaker overcurrent are automatically bypassed upon loss of voltage on the emergency bus and/or a safety injection actuation signal.

7. Verifying the diesel generator operates ** for at least 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . During the first 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months of this test, the diesel generator shall be loaded to an indicated target value of 2950 kW (between 2900-3000 kW)*** and during the remaining 22 hours2.546296e-4 days 0.00611 hours 3.637566e-5 weeks 8.371e-6 months of this test, the diesel generator shall be loaded to an indicated 2500-2600 kW***.

8. Verifying that the auto-connected loads to each diesel generator do not exceed the 2000 hour0.0231 days 0.556 hours 0.00331 weeks 7.61e-4 months rating of 3000 kW.

9. Verifying the diesel generator's capability to:

a) Synchronize with the offsite power source while the generator is loaded with its emergency loads upon a simulated restoration of offsite power, b) Transfer its loads to the offsite power source, and c) Proceed through its shutdown sequence.

This test shall be conducted in accordance with the manufacturer's recommendations l

regarding engine prelube and warmup procedures, and as app!icable regarding loading recommendations.

l

** This band is meant as guidance to avoid routine overloading of the engine. Loads in excess f of this band for special testing under direct monitoring of the manufacturer or momentary I variations due to changing bus loads shall not invalidate the test.

NORTII ANNA - UNIT 2 3/4 8-5 Amendment No. 42,48,165,

ELECTRICAL POWER SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) 4.8.1.1.2 (Continued)

10. Verifying that the following diesel generator lockout features prevent diesel generator starting only when required:

a) Remote Local Selection Switch b) Emergency Stop Switch

11. Verifying the diesel generator's hot restart capability by: i a) Operating the diesel generator ** loaded to an indicated 2500 to 2600 kW***

for 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months or until operating temperatures have stabilized, and b) Within 5 minutes of shutdown verify the diesel generator can be started ** and in less than or equal to 10 seconds of the start signal with voltage greater than or equal to 3960 volts and frequency greater than or equal to 59.5 Hz. The l steady state generator voltage and frequency shall be 4160 420 volts and 60 i 0.5 Hz.

c. 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 start in less than or equal to 10 seconds of the start signal and achieve a voltage greater than or equal to 3960 volts and a frequency greater than or equal to 59.5 Hz.

4.8.1.1.3 Each diesel generator 125-volt battery bank and charger shall be demonstrated OPERABLE:

a. At least once per 7 days by verifying that:

1. The parameters in Table 4.8-3 meet Category A limits and

2. The total battery terminal voltage is 2129 volts on a float charge.

b. At least once per 92 days and within 7 days after a battery discharge where the battery terminal voltage decreased below 110 volts or battery overcharge above 150 volts, by verifying that:

1. The parameters in Table 4.8-3 meet Category B limits and

2. There is no visible corrosion at either terminals or connectors, or the connection resistance of these items is less than 150 x 10 to the minus 6 ohms.

This test shall be conducted in accordance with the manufacturer's recommendations

regarding engine prelube and warmup procedures, and as applicable regarding loading l recommendations.

This band is meant as guidance to avoid routine overloading of the engine. Loads in excess of this band for special testing under direct monitoring of the manufacturer or momentary variations due to changing bus loads shall not invalidate the test.

NORTH ANNA - UNIT 2 3/4 8-6 Amendment No. 4 8, 84,165, w _. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

4 3/4.8 ELECTRICAL POWER SYSTEMS BASES 3/4.8.1 and 3/4.8.2 A.C. and D.C. POWER SOURCES AND DISTRIBUTION (Continued)

The testing of the largest post-accident load rejection in Surveillance Requirement (SR) 4.8.1.1.2.d.2, for demonstrating the OPERABILITY of the EDGs, is in accordance with the testing recommendations of Regulatory Guide 1.9, Revision 1, Section C.5.

The EDG testing in SRs 4.8.1.1.2.c,4.8.1.1.2.d 5,4.8.1.1.2.d. I 1.b), and 4.8.1.1.2.e separate the start requirements for voltage and frequency from the steady state limits. The 10-second start requires the EDG to meet the minimum values for voltage and frequency. The EDG's voltage must exceed the 95% value of rated voltage in order for the output breaker to automatically close. The minimum frequency requirement is based on the safety analyses assumption for steady state frequency. The steady state voltage and frequency limits are not required to be maintained during the 10-second start require ment. Following the fast start of the EDG, the time to reach steady state voltage and frequency is periodically monitored in the performance tests. The tests can be used to identify degradation of the gover,nor and voltage regulator performance. The EDG is unloaded in some portions of these surveillance tests and short-term variations in voltage ar.d frequency, outside the steady state limits may occur in this condition. The safety analyr.es assume the long-term steady state electrical power requirements for voltage and frequency to the ECCS equipment is 4160 420 volts and 60i 0.5 Hz.

In lieu of actual accident loading demonstration during the performance of SRs 4.8.1.1.2.d.4 and 4.8.1.1.2.d.6, the EDGs are allowed to supply the required loads by a combination of evolutions. This testing may include a series of sequential, overlapping, or tetal steps so that the entire connection and loading sequence is verified. This method of testing adequately verifies the capability of each EDG system to energize the emergency bus and supply the power necessary for the required safety equipment to mitigate analyzed events.

The Surveillance Requirements for demonstrating the OPERABILITY of the Emergency Diesel Generator batteries and the Station batteries are based on the recommendations of Regulatory Guide 1.129, " Maintenance, Testing and Replacement of Large Lead Storage Batteries for Nuclear Power Plants," February 1978, and IEEE Std 450-1980, "IEEE Recommended Practice for Maintenance, Testing and Replacement of Large Lead Storage Batteries for Generating l Stations and Substations," as modified by Amendment No. 84 issued March 25,1988.

Containment electrical penetration and penetration conductors are protected by either de-energizing circuits not required during reactor operation or by demonstrating the OPERABILITY of primary and backup overcurrent protection circuit breakers during period surveillance.

NORTH ANNA - UNIT 2 B 3/4 8-2 Amendment No. +3th484, i

3/4.8 ELECTRICAL POWER SYSTEMS BASES 3/4.8.1 and 3/4.8.2 A.C. and D.C. POWER SOURCES AND DISTRIBUTION (Continued)

The surveillance frequency applicable to molded case circuit breakers and/or buses provides assurance of breaker and/or fuse reliability by testing at least one representative sample of each rnanufacturer's brand of circuit breaker and/or fuse. Each manufacturer's molded case circuit breakers and/or fuses are grouped into representative samples which are then tested on a rotating basis to ensure that all breakers and/or fuses are tested. If a wide variety exists within any manufacturer's brand of n.olded case circuit breakers and/or fuses, it is necessary to divide that manufacturer's breakers and/or fuses into groups and treat each group as a separate type of breaker or fuse for surveillance purposes.

The OPERABILITY of the motor-operated valves thermal and overload protection and/or bypass devices ensures that these devices will not prevent safety-related valves from performing their function. The Surveillance Requirements for demonstrating the OPERABILITY of these devices are in accordance with Regulatory Guide 1.106, " Thermal Overload Protection for Electric Motors on Motor-Operated Valves," Revision 1, March 1977.

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NORTil ANNA - UNIT 2 B 3/4 8-3 Amendment No. .

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l Attachment 4 Significant Hazards Consideration Determination i

i North Anna Power Station Units 1 and 2 l Virginia Electric and Power Ccmpany

SIGNIFICANT HAZARDS CONSIDERATION The Technical Specifications surveillance requirements for the Emergency Diesel Generators require the frequency to be 60+1.2 Hz. This proposed change would change the frequency limit from 60 1.2 Hz to 60 0.5 Hz and separate the requirement of the EDG start from the steady state voltage and frequency limits.

This frequency limit change was implemented procedurally in 1995 to address the concems of a 1993 Westinghouse Nuclear Safety Advisory Letter (NSAL 93-022). The NSAL indicated that Westinghouse accident analyses assumed a steady state EDG frequency of 60 Hz, making no specific allowance for the effects on ESF pump performance at steady state frequency limits that are currently permitted by Technical Specifications.

Margin exists in the North Anna accident analyses to account for some level of frequency variation from 60 Hz, and the level of variation that has been evaluated by fingineering as acceptable is 0.5 Hz.

The change to the frequency limits is acceptable because the safety analyses assumptions for emergency power limits the frequency variations to 60 0.5 Hz and assumes that the EDG supplies the emergency bus with electrical power within 10 seconds of receiving an emergency start signal. The EDG output breaker will close with no electrical power applied to the emergency bus when the EDG output voltage reaches 95% of rated voltage. The minimum frequency requirement of 59.5 Hz is based on the steady state limit for the EDG. The EDG supplies the electrical power for the required equipment to mitigate the consequences of design basis events. The minimum voltage and frequency (3740 volts and 59.5 Hz) limits ensure that the ESF pumps will supply the sninimum flow necessary to maintain the fuel within the required parameters to prevent degradation.

Page 1 of 4

Virginis Electric cnd Pow:r Company his ravi;w:d the proposed Technical Specification changes against the requirements of 10 CFR 50.92 and has '

4 .

determined that the proposed changes would not pose a significant hazards consideration. Specifically, operation of the North Anna Power Station in accordance with the proposed Technical Specifications changes will not:

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! 1. Involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed change provides a more stringent requirement for the EDG l- frequency limit at steady state operation of 60 0.5 Hz from the current l 60 1.2 Hz. The change additionally provides a separation of the start requirements from the steady state limits for voltage and frequency. The change to the EDG frequency limit does not result in operation that will j increase the probability of initiating an analyzed event and does not alter j assumptions relative to mitigation of an accident or transient event. The l change to the frequency limit is acceptable because the safety analyses l assumptions for emergency power limits the frequency variations to 60 j i 0.5 Hz and assumes that the EDG supplies the emergency bus with l- electrical power within 10 seconds of receiving an emergency start signal.

The EDG output breaker will close with no electrical power applied to the emergency bus when the EDG output reaches 95% of rated voltage. The l l

minimum frequency requirement of 59.5 Hz is based on the steady state limit for the EDG. The EDG supplies the electrical power for the required j equipment to mitigate the consequences of design basis events. The minimum voltage and frequency (3740 volts and 59.5 Hz) limits ensure that the ESF equipment is maintained with the required electrical power to mitigate the cc7 sequences of an accident previously evaluated.

Therefore, this change does not involve a significant increase in the i

probability or consequences of an accident previously evaluated.

l Page 2 of 4

_ ___ _ _ _ _ . _ _ _ - _ _ - = _ - - _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ _ . _ - _ _ - - _ _ _ - _ _ _ - _

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l 2. Crrts thy possibility of a now or diff:rsnt kind of accident from any

! 1 accident previously evaluated.

l The proposed change provides a more stringent requirement for the EDG l frequency at steady state operation of 60 0.5 Hz from the current 60

! 1.2 Hz. The change additionally provides a separation of the start requirements from the steady state limits for voltage and frequency. The change does not introduce a new mode of plant operation and does not involve physical modification to the plant. The proposed change does impose different requirements. However, these char;ies are consistent with the assumptions in the safety analyses. Thus this change does not create the possibility of a new or different kind of accident from any I accident previously evaluated. I i

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3. Involve a significant reduction in a margin of safety.

The proposed change provides a more stringent requirement for the EDG frequency at steady state operation of 60 0.5 Hz from the current 60

)

l 1.2 Hz. The change additionally provides a separation of the start l

requirements from the steady state limits for voltage and frequency. The change to the frequency limit is acceptable because the safety analyses assumptions for emergency power limits the frequency variations to 60 l- 0.5 Hz and assumes that the EDG supplies the emergency bus with electrical power within 10 seconds of receiving an emergency start signal.

The EDG output breaker will close with no electrical power applied to the emergency bus when the EDG output reaches 95% of rated voltage. The minimum frequency requirement of 59.5 Hz is based on the steady state l -- i l . limit for the EDG. The EDG supplies the electrical power for the required l

! l l equipment to mitigate the consequences of desigri basis evenu The i minimum voltage and frequency (3740 volts and 59.5 Hz) limits ensure that the ESF equipment will be supplied with the required electrical power ;

to mitigate previously evaluated accidents. The margin of safety is j l :.

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l L_ _1_ _ ___ __. _

established through the design of the plant structures, systems and components, the parameters within which the plant is operated, and the establishment of the setpoints for the actuation of equipment relied upon to respond to an event. The change allowing the separation of the start requirements from the steady state voltage and frequency limits, due to the short time period allowed in this condition, does not significantly impact the performance of structures; systems or components relied upon for accident mitigation or any safety analysis assumptions. Therefore, the change does not involve a significant reduction in a margin of safety.

Page 4 of 4

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ML20236U871

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