ML20101F123

Suppl 1 to Application for Amend to License NPF-86, Consisting of License Amend Request 91-10,revising TS 3/4.8.1, AC Sources, Re Method of Verifying DG Hot Restart Capability

ML20101F123
Person / Time
Site:	Seabrook
Issue date:	06/19/1992
From:	Drawbridge B PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:
Shared Package
ML20101F107	List: ML20101F104 ML20101F123 ML20101F135
References
NUDOCS 9206240289
Download: ML20101F123 (6)

Text

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SEABROOK STATION UNIT 1 New Hampshire Yankee Facility Operating License NPF 86 Docket No. 50 443 License Amendment Request No. 91-10 Supplement 1 Revision to the Diesel Generator Surveillance Requirements This License Amendment Request is submitted by New Hainpshire Yankee pursuant to 10CFR50.90. The following information is enclosed in support of this License Amendment Request:

. Section 1 -

Introduction and Description of Proposed Changes Section ll -

Markup of Proposed Changes i

. Section ill -

Retype of Proposed Changes

.Section IV -

Safety Evaluation of Proposed Changes

)

Section V -

Determination of Significant Hazards for Proposed Changes

.Section VI -

Proposed Schedule for License Amendment issuance and Effectiveness

. Section Vll -

Enviro.1 mental Impact Assessment w

Sworn and Subscribed 'f 7- /

/ day ofme to/r/oefore d?this.

.n ,1992 -

, 74 4 / M bdO, c/, e o W h e h % db h BrucIIL Drawbridge /

-dNotary Public Executive oirector Nuclear. Pr6, duction mACY A D:Cnit;CO. May rurc y cmme, tpa xg 7 3, 7393 9206240289 pDit 920619 0 ADOCK 05000443 PDR

I. Jntroductiori and llescription of Proposed Channes A. Introduction The purpose of the proposed Technical Specification change is to revise Technical i Specification 3/4.8.1 ' A.C. Sourcer." to:

1. Revise the method of verifying diesel generator hot restart capability. Presently Technical Specification Surveillance Requirement 4.8.1.1.2f.7) verifies diesel generator hot restart capability by initiating a Loss of Offsite Power / Safety injection (LOP /SI) test within 5 minutes of completing the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> diesel generator run. The curient Technical Specification creates significant scheduling demands during an outage by reducing schedule flexib!!ity and imposing unnecessary operational burdens. The ,

revised Surveillance requirement will verify dicsci generator hot restart capability by either manually or automatically starting the diesel generator and verifying that it attains rated voltage and frequency within the required time. i i.o requirement to sequence on the LOP /S1 loads does not contribute to verifying the abihty of the diesel generator to start from normal operating temperatures.  ;

Regulatory Guide 1.108, Periodle Testine of Diesel Generator linits th rd n Onsig i filectric Power %tems at Nuclear Power Plants Position C.2.a($), which is the basis for the requirement to verify hot restart capability by performing a LOP /SI test immediately following the 24 hout test states the pur!mse of the requirement is tm

" demonstrate functional capability at full load temperature conditions #. The capability of the diesel generator to start from a normal operating temperature condition will continue to be verified. Demonstrating diesel generator hot restart capability without loading the engine with LOP /SI loads does not invaHdate or reduce the effectiveness of either test, provided normal operating temperatures are achieved prior to demonstrating hot restart capability.

Normal operating temperature conditions will be assured by perf irming the test within  ;

5 minutes of completing the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> diesel generator run. If fer some reason the surveillunce cannot be conducted within the 5. minute time period, or if the surveillance is unsuccessful, the engine may be brought to normal operating temperature by operating at a load of greater than or equal to 5600 kW and less than or equal to 6100 kW for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or until operating temperature has stabilized.

2. - Surveillance Requirement 4.8.1.1.2a.6) specifies l' tt that at least once per 184 days, that the diesel generator be rapidly loaded to g.; 4er than or equal to 6083 kW in less than or equal to 120 seconds. Rapidly loading the diesel generator in this ,

manner introduces mechanical stresses and engine wear. The purpose of this test is l to demonstrate that the dicscl generator is capable of accepting load by simulating the loading rate of the emergency power sequencer. This test does not validate any operational rcquirement which is not demonstrated by performance of Surveillance Requirements 4.8.1.1.2.f.4) and 6). These tests are the Loss of Offsite Power and Loss of Offsite Power / Safety injection f :sts. Performance of these tests demonstrate that the dicsci generators- are capable of ac cepting lead as it is sequenced by the emergency power sequencer.

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The:cfore, the part o' Suncillance itequitement 4.8.1.1.2f.0) to rapidly load the dicsci generator in less than or equal to 120 seconds % deleted.

3. A load range is being provided where applicable to preclude routine overload of the diesel generator. As presently written, during surveillance test:ng which requires loading of the die:,el generator, the operator must maintain load greater than the continuous diesel gcnerater load rating of 6083 kW This is to prevent grid induced transientr,, specifically changes in Volt Amps Reactive (VARS), from lowering the  ;

output of the diesel generator to less than the surveillance required load of 6083 kW.  !

Operation significantly above this load has manufacturer imposed limits on the time that this rating can be exceeded. Thus, providing a load range of greater than or equal to 5600 kW and less than or equal to 6100 kW will preclude significant routine exceedance of the diesel generator coritinuous load rating.

Similarly, the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> rating of the diesel generator is tested by operating ut a load of preater than or equal to 6697 kW. ~1 his requirement is revised to greater than or equal to 6300 kW and less than or equal to 67JO kW.  ;

Loading the diesel generators to these ranges will preclude routine overload of the diesel generators but will still demonstrate that the diest i generators are capable of i supporting operation of the emergency busses.

4. The term " ambient condition" is used in Surveillance Requirement 4.8.1.1.2a.5) t o describe the conodion from which the diesel generator is to be started. This term does not -ccount for the jacket water and lube oil warming systems which are continuously in operatmn. A more accurate term to describe the condition which the -

diesels are mainteined is

• standby" Therefore, to improve the clarity of the Technical Specification and to more accurately describe the condition in which the diesel generators are maintained, the term " ambient condition" is being replaced with

" standby conditions" in Surveillance requirement 4.8.1.1.2a.5), and the term standby conditions" is added to Surveillance Requirements 4.8.1,1.2f.4)h) and 4.8.1.1.2f.6)b). l S. -Several notes are being revised and or added as necessary. The purnose of the changes is to provide amplifying information for the applicable Technical Specification to enhance and improve its clarity. The details of these changes arc discussed in Section B below.

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-H. Description of Changes The following changes are proposed to Technical Specification 3/4.8.1:

1. The second ' sentence of the note at the bottom of page 3/4 8.3 is deleted. The note will now state: "All-starts for the purpose of these suncillances may be preceded by an engine prelube period" The second sentence is being deleted since the Seabrook Station emergency diesel generators are not gradually accelerated to operating speed.

The SURVEILLANCE REQUIREMENT to which this note is applicable is changed i

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e F from substep 5) to apply to the entire SUltVElLLANCE RiiOUIREMENT of 4.N.1.1.2 because the cugine prelube option is applicable to all test starts.

2. The term "a mbie nt condition" is replaced with the term " standby conditions" in SU RVElLLANCE R EQUIREM ENT 4.8.1.1.2a.5). The term " standby conditions" is inserted in SURVEILLANCE REQUIREMENTS 4. 8.1.1. 2 f. 4 ) b), 4.8.1. L 2 f. 5 ), and 4.8.1.1.2. f.6) . This term (standby conditions) more accurately describes the candition in which the diesel generators are maintained and accounts for the jackei water and lube oil warning r.ystems which are continually in operation.

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3. A land of " greater than or equal to 6083 kW" is replaced by a load range of *picater than or equal to 5600 LW and less than or equal to 6100 LW" in the f ollowing SURVEILLANCE REQUIREMENTS 4.8.1.1.2a 6) and 4.S.1.1.2L7) and to the note at the bottom of page 3/4 8 7. The lond range is provided to preclude routinely

, exceeding the continuous load rating of the diesel generator. Similarly, the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> load rating specified in SURVEILLANCE REQUIREMENT 4.8.L12f.7) is changed to a load range of " greater than or equal to 6300 kW and less than or equal to 6700 kW"

4. The- requirement of SURVEILLANCE R EQ U I R E M ENT 4.8.1.1.2a.6), to load the diesel generators "in less than or equal to 120 seconds

• is deleted. This test introduces mechanical stress and wear on the diesel engine and does not validate any operational requirement which is not already validated by performing other surveillances. l

5. The existing notes at the bottom of page 3/4 8 4 and 3/4 8-7 are being deleted for the following reasons;.1) the requirement to rapidly load the diesel generators has been deleted, 2} the note concerning diesel generator prelube has been relocated so that it applies to the entire SURVE!LLANCE REQUIREMENT and. 3) the diesel  ;

j generators at Seabrook Station are not gradually accelerated to operating speed. A new note stating: " Diesel generator louding may be in accordance with manufacturers recommendations, including a warmup period. The load range is provided to preclude routine overloading of the diesel generator. Momentary transients outside the load

range due changing bus conditions, do not invalidate the test." is being added, The information contained in the new note will provide the operator with additional information- concerning performance of the surveillance. These notes are applicable to SURVEILLANCE REQUIREM ENTS 4.8.1.1.2a.6) and 4.8.L t.2f.7),

The information in this note is also being added at the bottom of page 3/4 8 7. This will be in the form of a new note and revision to the existing note.

6. 'The requirement to verify diesel generator hot restart capability by performing a LOP /S1 test is replaced by a requirement to demonstrate hot restart capability by manually or automatically starting the diesel generator and verifying that rated voltage and . frequency are attained wit hin the required time. Specifically, " perform Specification 4.8.1.1.2f.6)b)" (the LOP /SI test) is replaced with " Verify that the diesel generator' starts on a manual or auto start signal,- attains generator voltage and frequency of 4160 + / 420 volts and 60 + /- 1.2 117 within 10 seconds and operates for at least 5 minutes"** The requirement to sequence on the LOP /SI loads does not contribute to verifying the ability of the diesel generator to start from normal 3

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operating temperatures. Demonstrating diesel generator hot restart capaleility without loading the engine with LOP /SI loads does not invalidate or reduce the ef fectiu ness of either t e r,t, provided normal operating temperatures are achiesed prior to demonstrating hot restart capability.

7, Since the LOP /S1 test will no longer be used to demonstra'e diesci gerirrator hot restatt capability, the note at the bottom of page 3!4 M is reworded to delete the reference to this test. Additionally, the sequirement to run the dicscl generator for i hout to achieve normal operating temperature is increased to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The latter requirement is more cona.tvative than the current 1 hout requirement and will continue to establish the required conditions to demonstrate diesel generator hot i restart capability. l i

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