ML20082G422

Application for Amend to License NPF-29,consisting of Proposed Amend to OL PCOL-91/16,revising Time Requirements for Operability Testing of Remaining Diesel Generators If Diesel Generator 12 Inoperable from Current 2 H to 24 H

ML20082G422
Person / Time
Site:	Grand Gulf
Issue date:	08/13/1991
From:	Cottle W ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20082G425	List: ML20082G422 ML20082G428
References
GNRO-91-00120, GNRO-91-120, PCOL-91-16, NUDOCS 9108190118
Download: ML20082G422 (9)

Text

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Em Entergy Opermuuns. hic.

cr: ENTERGY

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W. T Cottle August 13, 1991 U.S. Nuclent Regulatory Commission Hall Station Pl-137 Wa sh i ngt on, 11. C.

20555 At tent lon Docornent. Cont rol Desk Subjnct :

Or nied Col f Nuclent St at loti Unit 1 Doel'e t No. 50 41(.

hitense No. NPP-29 Revinion of Diesel Generator 13 Inoperability Action

. St at ement Propot.ed Amendment to the Operating 1.icense (PCOIM 1/16)

GNRO-91/00120 Gent lemen:

r.ntntgy Operations, Inc. is submitting by this letter a proposed amendment to thn Grand Gulf Nuclear Station Operat ing 1.lconse.

The proponnd nmendment. chnogns t he tiene requiremnnt for opnrahility insting of thn r emainirig diesel genernt ors if 1)ienol Generator 13 is inopernhin from thn cut rent 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 24 hoars.

In accordance with the prov18fon" of 10CPR50.4, the nigned orfginn1 of the regnnnt ed amendment. in oncloned. providns the discussion and justificat ion to support the requer,ted amendment.

This amendment request hnn bonn revieund nnd necept ed by the Plant Sa fet y Review Commit t en nud t he Sa fet y Poview Commi t tee.

Ilnsed on the guidelines given in 10CfR50.92, F.nt et gy Operat lons han concluded that this proponnd amendment involves no significnat hn?.ards considerntlens.

Yours truly, M7 Cocu..,

WTC/Si1M/mtc attnchments:

1.

Affirmation par 10C'r P 50, 30 2.

G6NS PC01.-91/16 cc-(Son Next Pn r,e )

G9107031/SNhlCFI,R - 1 l

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9103190118 910U1:3 ea n

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O' August 13. 1991 GNRO-91/00120 Page 2 of 3 i

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Mr. D. C. Illutz (w/n)

Mr. J. L. Mathis (w/a) i H r. R. 11 McGobec (w/a)

Mr. N. S. Reynolds (w/a)

Mr.11. L. Thomas (w/o)

Mr. F. W. Titus (w/n)

Mr. Stnwnrt D. Ebnter (w/a)

Regionn1 Administrntor U.S. Nucionr Regn1nt ory Commisalon Region 11 101 Marietta St., N.W.,

Sutto 2900 i

Atlanta, Georgin 30323 i

Hr.1.. L. Kintnor, Projnct Hannger (w/n)

Offico of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Hall St op 11D21 Washington, D.C.

20555 Dr. Alton B. Cobb (w/n)

Stato linnith Of ficer State Donrd of llenith P.O. Box 1700 Jackson, lif ssissippi 39205 l

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1 09107031/SNLICTI.R - 2 I

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IIETORE Tile UNITED STATES NUCLEAR REGUI.ATORY COMMISSION I

LICENSE NO, NPF-29 DOCEET NO. 50-416 IN Tile HATTER OF MISS1881Pt'l POWER 1. LIGHT COMPANY and SYSTEM ENERGY RESOURCES, INC.

and SOUTil MISSISSIPPI ELECTUIC POWER ASSOCI ATION and ENTERGY OPERATIONS, INC.

AEEIRtiall0N

1. W. T. Cottle, being duly sworn, stato that 1 am Vice President, Oporations GGNS of Entorgy Operations, Inc. ; that on behalf of Entergy Operations, Inc., System Energy Resources, Inc., and Sonth Mississippi Electric Power Association 1 am authorized by Entorgy Operations, Inc. to sign and file with the Nuc1 car Reguintory Commission, this application for amendment of the Operating Licenan of the Grand Gulf Nuc1 car Station; that I signed this application as Vice President, Opnrations GGNS of Entergy Operations, Inc. ; and that the statements modo and the matters set forth therein are true and correct to the best of my knowledge.

l information and bnlief.

MP Cheer W. T. Cottin STATE OF HISSISSIPPI COUNTY OF C1.AIDORNE SUBSCRIBED AND SWORN TO before me, a Notary Public, in and for the County and Stato abovo named. this N

day of h E4 1991.

N (SEAL) h&\\

aben no m Notary hbli

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My commission expires:

g ggg3a Lyses July 1.1993

.G9107031/SNLICPLR - 4

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Attachmerit 2 to GNRO-91/00120 PROPOSED CilAMGE TO Tile OPERATING LICENSE REVIS10N OF DIESEL GENERATOR 13 INOPER/831LITY ACTION STATEHENT (GGNS I' COL-91/16) _

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LG9107031/SNLICFLR

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. to GNRO-91/00120 4

page 1 of 5 A.

SUBJECT 1.

NL-91/11 Revision of the Action Statement for the Inoperabilit y of Diesel Generator 13 i3

.k4 2.

Af fected Technical Specificat lon:

1.6 Action Statement

-.8.1.1.g page 3/4 8-2

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DISCUS 9 ION

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1.

This proposed amendment to the Grand Gulf Nuclear Station (GGNS)

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Technical f.pecifIcations (TS) changer the time requirement for 11 demonstrating the operability of diet el generators (DGs) 11 and M

12 If DG 13 is inoperabic from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

2'

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r'. - cntly, if DG 11 or 12 is inoperable, testing of the

• ' 'V rer..alniny, diesels is required by Action 3.8.1.1.h within 24 E

bourt. lloweve r, if DG 13 is it.upe rabl e, the remaining diesels Q$+ -

must be ter.ted in accordance witn Action 3.G.1.1.g with!n E

!.c hours.

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GGNS proposes to remove the incons'stency in tha time requirements between Action 3.8.1.1.b and Action 3.8.1.1.g by increasing the allowed actton time for Action 3.8.1.1.g from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

'arked up to refic:t the 4.

The affected TS page is attached d

proposed change.

C.

JUSTIFICATION 1.

I f o t t he r DG 11 ot 12 19 i no,

' ale, present Action 3.8.1.1.b allows 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to test the verability of the teamining DGs; if DG 13 is inoperable, p esent. Action 3.8.1.1.g requires DGs 11 and 12 to be tuated within P hoto s 2

2.

GGWS has evaluated the be.ses for the dif feront action times.

Our evaluation of the three diesels and their associated safe +

functions has led us to conclude that there is no basis for tha e

differencu io alicwed action times. To t13 contrary, we have determined that extending the requirement to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> will benefit reliability and safety by decreasing the number of unplanned starts and e lucing the divers ton of operator attention from.their u.armal safety-related duties.

A summary of our evaluation is provided below.

3.

Sa fety Function of Rem,aining, D_lesels t

a, When one of the AC power :ources becomes inoperable. the intent of the renuired cctions.is to confirm operability cf the remaining DGs und their associated safety functions),

consistent with the tafety significance.

In other words, a

the time requirement for starting the rema ining DGs should be inveraely pronort f onal to their safety significc ces.

W91C7031/SNLICFLR - 6

.. to GNRO-91/00120 c.

l' Pago 2 of-5 b.

Present Action 3.8.1.1.g implies grantor safety significances for IX% 11 and 12 (a 2-hour start time) LFen for DG 13 (a 24-hour start time when either DG 11 or 12 is inoperable)'. -

'The sofoty significances of the throo DGs are roughly

.c.

comparabloJ althougi. the unac*'. lability of DG;13 contributes slightly m%

to the cvorall risk at Grand Gulf ' hat either DG:11 or 12, in~NUREG/CR-4550, Vol. 6, Rev. 1, Part 1

( Analysis of _ Core Damago Frequoney: - Grand Gulf, Unit 1

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Internal Events).-Tablo 5.4-1, cortnin events are ranked in I

uccordance with-their contributions to risk reduction. The risk reduction value for DG 13 failure to start is cited as j

6.81E-7, whereas the comparablo values for'DGs 11 and 12 are 4.85E-7.and 4.87E-7, respectively.

Based on risk significanco, the Limo requiremont in present

.-Action 3.8.1.1.g.is clearly inappropriate when compared with the requirements for DGs 11 and 12.

Because the risk significanco is essentially comparablo among the throo DGs,

.l the timo'to start the remaining DGs should also bo

-comparable.

4..

Effect of DG Air' Rolls on Diesel-Reliability a.

In accordance with License Condition-2.C.(25), DG air roll tests are not required when the plant is in an Action statement of TS 3/4.8.1.

In spita of this allowanco, performing an air roll-test before starting a diosol is proforable sinco severe ougino damago can occur if an unsatisfactory condition (for examplo, water in a cy]Indor) in not-identified and corrected before a start =

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b. - The 'icnorit associated with air rolling before a diesel start outweighs any possible gain due to datormining DG l.

operability in 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

By extending the timo requirement l~

of Action 3.0.1.1.g to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, all manual DG starts with i

nir rolls ce"'d; be norformed' in n more orderly fashion, thus I

l' identifying potential-degradation-in suspnct cy' ior heads before the start.

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5.

Reduction in Unnoc.ossn(y_ Diesel Starts s

n.

Repeated starts cause mechanical str?ss and woar on a diosol i

L engine. Also, there is significant exponditure of manpower atsselated with diosol testing.

Thorofore, reducing tho number of unnecessary DG starts actually onhances rollability and ci.hancos saroty by climinating operator bu rd en.

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G9107031/SNLICFLR - 7

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' Attachment 2 to GNRO-91/00120 Page 3 of 5 3

b.

If-an inoperable DG 1_s restored before test. fag of the other diesels is' required, the remaining dicsols need not be started.

Since planned maintenance and simple repairs can-normally be completed within-24 hours, many diesel starts Src prevented if DG 11 or 12 is inoperable.

But if DG 13 is inoperable, the other diesels must bn started since those

=same tasks cannot usually be completed within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. A review of the '1990 maintenance history for DG 13 follows.

Table _1 Total llours Dat_c

_Refluired Action DG_13 Inop_

01/25/90*

Start s on DGs 11 & 12 -

15.8 03/22/90*

Starts on DGs 11 & 12 17.2 05/17/90*

Starts on DGs 11 & 12 15 07/25/90 Starts on DGs 11 & 12 34.75

.11/30/90*

Starts on DGs 11 & 12 16.31 12/14/90 Starts on DGs,11 & 12 16

• planned maintenance As'shown in the above table, the proposed change would have

. eliminated 10 unnecessary starts on DGs 11 and 12 during the 1990 calendar year, the exception 1being the 34.75 hour8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br /> outage or. 07/25/90.

In comparison, outages on DG 11 and 12 caused only two starts for each of the other DGs.

c, Starting a DG icquires no less than thren operators, two locally and another remotely in the control room, two Instrumentation technicians and significant supervisory attention.

The tasks associated with starting a diesel conwist of overspoed checks, prolubes, air rolls and inspections on each diest' as well as remote _ monitoring during the ent.fre evolution.

For a DG test of 2-hour duration, this amounts to 10__ manhours during which operators-and-maintenance personnel are diverted from their normal-safety-related duties, including recovery of DG 13.

d.

Extending the Action t.ime to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for Action 3.8.1,1.g will climinato many unnecescary starts on IN, 11 and 12.

Long-term rollability

.11 be improved by reducing the number 01 diesel starti tsquired, thereby reducing stress and wear on the er.gt ae.

In addition, safety is enhanced by climinating the asm. lated operator burden and allowing'the operator's attention to focus on vit.nl reactor control and monitoring activities.

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6.

Safety Funucion Recovery a.-

When a DG hm.omes inoperable, ef fort.s should be a ime<1 et restorirg full safety function, i.e.,

the recovery of the Inoperable diesel.

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J. to GNR0-91/00120-f Page 4 of 5 b.

This is~true if'I9 11 or 12 is inoperable; however, if DG 13 becomes inoperabic, significant manpower must be allocated for diesel testing as well as fer restoration of DG 13. - A 24-hour testing requirement would allow more initial effort

.to be' spent on restoring DG 13, thus decreasing the time the diesel is inoperabic, c.

Changing the time requiremen*: in Action 3.8.1.1.g to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> would benefit safety since effort currently expended on diesel testing could be used for recovering DG 13, hence restoring full safety function sooner.

D.

NO SIGNIFICANT 11AZARDS.CONSIDERA110NS 1.

Entergy Operations, _Inc. Je pioposing that Action 3.8.1.1.g for-Diesel Generator 13 inoperability be revised to require the operability determinations of Dienci Generators 11 and 12 he performed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> instead of the current 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

2.-

The Commirsfon has provided standards for determining whether a no significant hazards consideration exists as stated-in 10CFR50.92(c). A proposed amendment to an operating license involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not:

(1) involve a significant increase in the probability or consequerces of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident -from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

3.

Entergy Operations has evaluated the no significant hazards

-considerations in its request for a license amendment.

In accordance with 1CCFR50.91(a), Entergy Operations is providing the analysis f the proposed amendment-aga'nst the three standards in 10CFR53.92:

a.

No significant increase in the probability or consequences of an -accident previously evaluated results #m. this change.

(1) This change will not affect the nethod by which system operability is determined oc the operation of the-diesel generators, The change will only extend the time requirements for demonstrating. adequate diosci operability when Diesel Generator 13 is inoperabic from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

This change is consistent with Action 3.8.1.1.b concerning an_ inoperable Diesel Generator 11 or 12.

(2) This change will decrease the number of required diesel generator starts, hence engine wear and stress, and increase reliability. When Diesel Generator 13 is inoperable but restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />,- two diesel.

G9107331/SNLICFhR - 9

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page 5 of 5 starts arn prevented nnd rnllability is improved, llone n, the probability _of an accident previously evaluated is not increased.

(3) Since the proposed change will not impact plant design or require the modification of equirment designed to mit.igate the events of an accident, the consequences of an accident already evaluated ar;, not changed.

The dinsol generators will continun to_porform the necessary emergency functions.

(4) Tho rn fore, the probability or consequences of previously analyzed accidents are not increanod.

- b. - Tlio change would not crentn ti.o possibility of a new or different kind of accident from any previously analyzed.

(1) The proposed chango will not require the addition, doletion or modi fication of any plant hardware and no new modes of plant operation or test.ing will be introduced.

(2) The method by which any safety-related system performs its'funecion will not be changed. The methods for verifying component or system operabilit'y will not

-change.

(3) _Therefore, operating the plant with the proposed chango will not creato. the possibility of a ne-or different kind of accident from any accident previously evaluated, c.

This chnnge would not involve a significant reduction in the margin:of safety.

(1) The proposed chango does not a f feet -the methodology used in the offsito dosn annlysis or the acceptanco -

criteria associnted with any accidentc analysis.

(2) 'Thn diesel generators will continun to function as i

power sources for the emergency core cooling systems.in the event of a loss of offsito power or a LOCA signal, f

l Allowing 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.to perform two dicsol generator I

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start s will actually nnhnnco safety by reducing gorator burden and by increasing. thn avn11 abilities of Dienn1 Generators 11 and 12..

(4) The re fore, this change will not involve a reduction in

- the margin of safoty.

4.

Based on the abovo evaluation, operation in accordanco with the proposed aandment involvna no significant hazards cons id e ra t i o;.s.

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