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Proposed Tech Specs,Revising Requirements for Monthly D/G Start Surveillance 4.8.1.1.2.a.4 & 10-yr Interdependence Surveillance 4.8.1.1.2.e
	ML20078Q483
Person / Time
Site:	Sequoyah
Issue date:	12/16/1994
From:	; TENNESSEE VALLEY AUTHORITY
To:	;
Shared Package
ML20078Q470	List: ML20078Q468; ML20078Q483;
References
	NUDOCS 9412220212
	Download: ML20078Q483 (10)
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1 ENCLOSURE 1 .'

l PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 .

't (TVA-SON-TS 94-16)

I LIST OF AFFECTED PAGES Unit 1 ;

3/4 8-3 3/4 8-5 Unit 2 3/4 8-3 3/4 8-5 i

2220212 941216 p ADOCK 030oo377 Ann

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d i ELECTRICAL POWER SYSTEMS SbRVEILLANCEREOUIREMENTS(Continued) 4.8.1.1.2 Each diesel generator set shall be. demonstrated OPERABLE:

a. In accordance with the frequency specified in Table 4.8-1 on a STAGGERED TEST BASIS by:

1. Verifying the fuel level in the engine-mounted day tanks.

2. Verifying the fuel level in the 7 day tank. l

3. Verifying the fuel transfer pump can be started and transfers ,

fuel from the storage p e ine n fue t '

4. *Verifyingthedieselstartsfromambientconditionand$$$8; l

. r;t;; to et h::t 000 rp.; in less than or equal to 10 secondsx Rll3 ,

4he generator voltage and frequency sh;11 b;lf9001690 volts and 60 i 1.2 Hzc.;ithir 10 ;;;;r.d; aft;r th; : tert :ig:.;1x The l-

diesel generator shall be started for this test by using one of ,

the following signals with startup on each signal verified at kS6 least once per 124 days:

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a) Manual.

b) Simulated loss of offsite power by itself. RS6 I c) An ESF actuation test signal by itself.

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Verifying the generator is synchronized, loaded between 3960 kw ill77 and 4400 kw in less than or equal to 60 seconds, and operates l for greater than or equal to 60 minutes, and ,

6. Verifying the diesel generator is aligned to provide standby power to the associated shutdown boards.

b. At least once per 31 days and after each operation of the diesel '

where the period of operation was greater than or equal to I hour by checking for and removing accumulated water from the engine-mounted fuel tanks.

c. At least once per 92 days and from'new fuel oil prior to addition to i the 7-day tanks by verifying that a sample obtained in accordance with ASTH-D270-1975 has a water and sediment content of less than or equal to .05 volume percent and a kinematic viscosity 9100*F of

greater than or equal to 1.8 but less than or equal to 5.8 centi-stokes when tested in accordance with ASTM-D975-77, and an impurity level of less than 2 mg. of insolubles per 100 ml. when tested in accordance with ASTM-D2274-70. ,

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The diesel generator start (10 sec) and load (60 sec) from standby conditions shall be performed at least once per 184 days in these surveillance tests. RS6

'N All other diesel generator engine starts and loading for the purpose of this ,

.) surveillance testing may be preceded by a le start, followed by gradualaccelerationtosynchronousspeed(p00 rpm), nchronization, and gradual loading. L- BrPR.oximaitt.y SEQUOYAH - UNIT 1 3/4 8-3 Amendment No. 52,64,99,109,137, 173 November 29, 1993

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1 ELECTRICAL POWER SYSTEMS '

I SURVEILLANCE REQUIREMENTS (Continued) c) Verifying that all automatic diesel generator trips, except engine overspeed and generator differential, are automati-cally bypassed upon loss of voltage on the shutdown board and/or 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 to 2.25 hours2.893519e-4 days 0.00694 hours 4.133598e-5 weeks 9.5125e-6 months of this' test, the diesel generator shall be loaded between 4620 kw and 4840 kw and between 2380 kvar and 2600 kvar and during the remaining hours of this test, the diesel generator shall be loaded between 3960 kw and 4400 kw and between 2140 kvar and 2370 kvar.

RL77 The generator voltage and frequency shall be 6900 i 690 volts and 60 i 1.2 Hz within 10 seconds after the start signal; the R113 steady state generator voltage and frequency shall be maintained within these limits during this test. Within 5 minutes after grig completing this 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months test, perform Specification 4.8.1.1.2.d.4.b.

8. Verifying that the auto-connected loads to each diesel generator a68 do not exceed the continuous rating of 4400 kw.

9. Verifying the diesel generator's capability to:

a) Synchronize with the offsite power source while the genera-tor is loaded with its emergency loads upon a simulated restoration of offsite power.

b) Transfer its loads to the offsite power source, and c) Be restored to its shutdown status.

10. Verifying that the automatic load sequence timers are OPERABLE with the setpoint for each sequence timer within i 5 percent of its design setpoint.

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

a) Engine overspeed b 86 GA lockout relay

e. At least once per 10 years or after any modifications which could affect diesel generator interdependence by starting the diesel E generators simultaneouslyx during ;hatde.;ry and verifying that ee nca diesel generator / accelerate to at least 000 r-- in less than or equal to 10 seconds g 8htmEVD bqoot lao Vouis Ano I,01 1. 2. H r. .

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-SEQUOYAH - UNIT 1 3/4 8-5 Amendment No. 52,64,109,114,137, 173 November 29, 1993 L

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ELECTRICAL POWER SYSTEMS.

< SURVEILLANCERE0VIREMENTS(Continued) 4.8.1.1.2 Each diesel generator set shall be demonstrated OPERABLE:

a. In accordance with the frequency specified in Table 4.8-1 on a STAGGERED TEST BASIS by:

1. Verifying the fuel level in the engine-mounted day tanks.

2. Verifying the fuel level in the 7 day tank.

3. Verifying the fuel transfer pump starts and transfers fuel from

,__, -Qe ,$orag_e_syitem_tpJhe engipo},pd fgel_ tanks

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Verifying the diesel starts from ambient condition and ::::..

retes te et least 500 g in less than or equal to 10 secondsg ggg

-Me generator voltage and frequency :h:11 by900 i 690 volts and 60 i 1.2 Hz,within 10 :::end: eft:r th .:rt :ign:1g The diesel generator shall be started for this test by using one of the following signals with startup on each signal verified at least once per 124 days:

n f a) Manual.

b) Simulated loss of offsite power by itself. R44 g c) An ESF actuation test signal by itself.

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Verifying the generator is synchronized, loaded between 3960 kw and 4400 kw in less than or equal to 60 seconds, and operates for greater than or equal to 60 minutes, and

6. Verifying the diesel generator is aligned to provide standby power to the associated shutdown boards.

b. At least once per 31 days and after each operation of the diesel where the period of operation was greater than or equal to I hour by checking for and removing accumulated water from the engine-mounted fuel tanks.

c. At least once per 92 days and from new fuel oil prior to addition to the 7-day tanks by verifying that a sample obtained in accordance with ASTH-D270-1975 has a water and sediment content of less than or equal to .05 volume percent and a kinematic viscosity 9100*F of greater than or equal to 1.8 but less than or equal to 5.8 centi-stokes when tested in accordance with ASTM-0975-77, and an impurity level of less than 2 mg. of insolubles per 100 ml. when tested in accordance with ASTM-02274-70.

The diesel generator start (10 sec) and load (60 sec) from standby conditions R44 shall be performed at least once per 184 days in these surveillance tests.

, T All other diesel generator engine starts and loading for the purpose of this j surveillance testing may be preceded by an na isile start, followed by gradual acceleration to synchronous speed 00 rpm), n o .ation, and gradual loading. gppto g g SEQUOYAH - UNIT 2 3/4 8-3 Amendment No. 44,56,88,99,123, 164 i November 29, 1993 j J

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ELECTRICAL

. POWER SYSTEMS SURVEILLANCE REQUIREMENTS-(Continued) c)- Verifying that all automatic diesel generator trips, except engine overspeed and generator differential, are automati-cally bypassed upon loss of voltage on the shutdown board and/or safety injection actuation signal.

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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 to 2.25 hours2.893519e-4 days 0.00694 hours 4.133598e-5 weeks 9.5125e-6 months of this test, the diesel generator shall be loaded between 4620 kw and 4840 kw and t between 2380 kvar and 2600 kvar and during the remaining hours of this test, the diesel generator shall be loaded between 3960 kw and 4400 kw and between 2140 kvar and 2370 kvar.

The generator voltage and frequency shall be 6900 i 690 volts RS6 .

and 60 i 1.2 Hz within 10 seconds after the start signal; the '

steady state generator voltage and frequency shall be maintained within these limits during this test. Within 5 minutes after ,

completing this 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months test, perform Specification 4.8.1.1.2.d.4.b. j

8. Verifying that the auto-connected loads to each diesel generator RS6 do not exceed the continuous rating of 4400 kw.

9. Verifying the diesel generator's capability to: R41 a) Synchronize with the offsite power source while the genera-g tor is loaded with its emergency loads upon a simulated n restoration of offsite power. ,

b) Transfer its loads to the offsite power source, and >

c) Be restored to its shutdown status.

10. Verifying that the automatic load sequence timers are OPERABLE R41 with the setpoint for each sequence timer within i 5 percent of its design setpoint.

11. Verifying that the following diesel generator lockout features R41 prevent diesel generator starting only when' required:

a) Engine overspeed ;

b) 86 GA lockout rela

e. At least once per 10 years or after any modifications which could affect diesel generator interdependence by starting the diesel generators simultaneouslyx dab;; f.;td=x and verifying that e e Enca diesel generator / e n ;1er;te te et 1 ::t ^^^ c 4 1n less than or equal to 10 secondsy, Acmtycs M OOT-(Ao Vot.T3 A u b (o o i L 2. H z . ;

i A A SEQUOYAH - UNIT 2 3/4 8-5 Amendment No. 41,56,123, 164 !

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ENCLOSURE 2 i PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SON TS-94-16) t DESCRIPTION AND JUSTIFICATION FOR DELETION OF DIESEL GENERATOR 900 REVOLUTIONS PER MINUTE (RPM) REQUIREMENT t

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Descriotion of Chanae ;

TVA proposes to modify the Sequoyah Nuclear Plant (SON) Units 1 and 2 Technical 1 Specifications (TSs) by revising Surveillance Requirements (SRs) 4.8.1.1.2.a.4 and 4.8.1.1.2.e. The proposed revision removes the 900 rpm requirement for monthly and 10-year surveillances that verify diesel generator (D/G) start times. D/G acceleration will continue to be verified by the timed frequency requirements in each of these specifications. Necessary word changes have been incorporated to facilitate this deletion and a clarification of synchronous speed has been included. In addition, the requirement to perform the 10-year interdependence test during shutdown conditions has been removed to allow performance during power operation.

Reason for Channe The SON D/Gs have traditionally performed with machine accelerations that resulted in an overshoot of the desired 900 rpm setpoint and a rapid convergence to the setpoint. The steady-state speed of the D/Gs (as reflected in TSs)is required to ,

result in a frequency of 60 plus or minus 1.2 hertz (Hz). This frequency range represents a D/G speed of 900 plus or minus 18 rpm; however, the corresponding TS requirement of at least 900 rpm does not provide a similar allowable tolerance band. TVA is in the process of installing improved speed controllers for the D/Gs that maintain better control of the increases in machine speed. As a result, the typical overshoot experienced at SON has been eliminated on the D/Gs that are modified. This response is more desirable because of the improved loading transient responses and reduced stress on the machine while maintaining acceptable acceleration times. However, for speed setpoints or meter indications that could drif t slightly lower than the 900 rpm value, the D/Gs may appear to f ail or actually f all short of reaching 900 rpm even though an acceptable frequency is achieved.

This result would violate the literal wording of TSs even though the D/G was performing in a more desirable manner. Failures of this nature will result in inappropriate valid D/G start failures and possible accelerated D/G testing if the 900 rpm requirement is not removed. Therefore, the proposed changes remove the 900 rpm requirement, but will retain the frequency limits for D/G operability. The word changes required to implement this deletion do not alter other portions of the TS requirements. The 900 rpm synchronous speed value found in the footnote for Survoillances 4.8.1.1.2.a.4 and 4.8.1.1.2.a.5 is retained with a clarification that it is an approximate value. The synchronous speed for the SON D/Gs is unchanged but varies slightly depending upon the power grid frequency at any given time.

For Surveillance 4.8.1.1.2.e, the removal of the words "during shutdown" is proposed because this surveillance requires the four D/Gs to start simultaneously and would affect both units. Therefore, to perform the 10 year interdependence test during shutdown, both units would be required to be shutdown. Performing this test only during a two unit shutdown would be an unnecessary restraint. SON does not schedule two unit shutdown outages and this implication would make the performance interval of this surveillance uncertain or require this type of outage every 10 years. This change, as well as the 900 rpm deletion, is consistent with the latest version of standard TS (NUREG-1431).

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1 Justification for Channes The proposed change to remove the 900 rpm requirement in Surveillances 4.8.1.1.2.a.4 and 4.8.1.1.2.e does not change the intent of these tests to verify that the D/Gs can accelerate to rated speed within 10 seconds. The frequency requirement satisfies the speed limits to ensure the D/G is ready to accept accident loads. Therefore, no relaxation of the TS requirement is realized by this proposal and potentialinconsistencies between the 900 rpm or greater requirement and the 60 plus or minus 1.2 Hz is eliminated. This change is consistent with NUREG-1431 such that only the voltage and frequency limits are specified for the 10 second D/G start verification. The deletion of the shutdown requirement for the 10-year interdependence test does not alter the intent of this verification and allows for test performance under expected plant conditions. This change is also consistent with NUREG-1431.

These proposed changes will provide test requirements that are the same as NUREG-1431 with the following conservative exceptions. For Surveillance 4.8.1.1.2.a.4, the additional requirement to start the D/G by using one of the three emergency start signals on a rotating basis is not removed. This requirement is met in NUREG-1431 during the 18-month surveillances and is not specified during monthly testing. For Surveillance 4.8.1.1.2.e, the additional requirement to verify D/G interdependence after modificaticns that could affect this capability is also maintained. This requirement is no longer found in NUREG-1431 and evaluations of the conversion from previous standard TS do not indicate the basis for the deletion. Both of these additional requirements are conservative with respect to NUREG 1431 and will not adversely affect testing to ensure D/G operability. TVA is evaluating thes9 changes, in addition to other line-item improvements,in accordance with NUREG 1431 and the recommendations of NRC regulatory guides and considering the specific SON design features, as a separate l effort to expedite processing of this request. Necessary TS changes determined by I this effort will be submitted for NRC review and approval. l l

Environmental imoact Evaluation !

The proposed change does not involve an unreviewed environmental question because operation of SON Units 1 and 2 in accordance with this change would not:

1. Resuit in a significant increase in any adverse environmentalimpact previously evaluated in the Final Environmental Statement (FES) as modified by NRC's j testimony to the Atomic Safety and Licensing Board, supplements to the FES, i environmentalimpact appraisals, or decisions of the Atomic Safety and )

Licensing Board. ;

2. Result in a significant change in offluents or power levels.

3. Result in matters not previously reviewed in the licensing basis for SON that may have a significant environmentalimpact.

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ENCLOSURE 3 -

PROPOSED TECHNICAL SPECIFICATION CHANGE SEQUOYAH NUCLEAR PLANT (SON) UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328 (TVA-SON-TS-94-16) l 1

DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION i

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Significant Hazards Evaluation TVA has evaluated the proposed technical specification (TS) change and has determined that it does not represent a significant hazards consideration based on criteria established in 10 CFR 50.92(c). Operation of Sequoyah Nuclear Plant (SON) in accordance with the proposed amendment will not:

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

The proposed changes to these surveillances do not alter the intent or methods for verifying diesel generator (D/G) operability. The intent of the 900 revolutions per minute (rpm) requirement is still maintained by the 60 plus or minus 1.2 hertz (Hz) requirement with acceptable tolerances. The deletion of the requirement to perform interdependence testing during shutdown does not alter the test but does provide reasonable flexibility to perform testing during power operation. By testing this function at power the probability and consequences of an accident are not increased. These surveillances verify operability of the D/Gs and do not impact the availability of D/Gs for accident mitigation. In addition, these tests, as well as the D/Gs, can not be the source of an accident. These proposed changes will not increase the probability or consequences of an accident.

2. Create the possibility of a new or different kind of accident from any previously analyzed.

The D/G and TS testing to verify operability are not postulated to create an accident. The affected surveillances are not changed in intent and will be performed in the same manner. Testing D/G starts during power operation is conducted on a weekly basis, therefore,10-year interdependence testing under these conditions will not present additional accident generation concerns.

Therefore, the proposed changes will not create a new or different kind of accident.

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

The testing requirements affected by the proposed changes will continue to verify D/G operability within the same or more conservative limits, intent, and testing methods. The changes provide flexibility in verifying D/G speed during ambient starts and relaxed operating conditions for performing interdependence tests. This flexibility does not lessen the operability verification requirements for the D/Gs or the margin of safety provided by the D/Gs. Therefore, the proposed changes do not reduce the margin of safety, v

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ML20078Q483

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