ML20113D135

Forwards Requested Info to Complete Review of Station Response to GL 95-07, Pressure Locking & Thermal Binding of SR Power-Operated Gate Valves

ML20113D135
Person / Time
Site:	Grand Gulf
Issue date:	06/28/1996
From:	Hutchinson C ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-95-07, GL-95-7, GNRO-96-00078, GNRO-96-78, NUDOCS 9607030030
Download: ML20113D135 (7)

Text

T

. &.ENTERGY y

Ent:rgy Opsrttirnz,Inc.

eo sox 7se Port Gbson.MS 39150 Tel 601437 2800 C. R. Hutchinson I vce Presdent Opsatuts Grand Gulf Nuckar Statcn June 28, 1996  ;

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U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C. 20555 Attention: Document Control Desk

Subject:

Grand Gulf Nuclear Station Docket No. 50-416 License No. NPF-29 Response to Generic Letter 95-07 Request for Addit!.onal Information GNRO-96/ 00078 Gentlemen:

Our submittals of October 11, 1995 (GNRO-95/00113)and February 13, 1996 (GNRO-96/00011) were made in response to the requirements of Generic Letter 95-07, Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves . By letter dated May 29, 1996 (GNRI-96/00123), the NRC requested additional information pertaining to our submittals and Generic Letter 95-07.

The requested information is attached for your use to complete your review of Grand Gulf Nuclear Station's response i to Generic Letter 95-07. Please contact Ms. Rita Jackson at (601) 437-2149 if you have questions.

Yours truly, f

< r CRH/RRJ attachment: Response to NRC Request for Additional Information \

cc: (See Next Page) 8IP60703OO30 960628 PDR ADOCK 05000416 P PDR -

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June 28, 1996 GNRo-96/00078

Page 2 of 3 l

l l l l cc: Mr. J. Tedrow (w/a) i Mr. R. B. McGehee (w/a)

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

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

Mr. J. W. Yelverton (w/o)

I Mr. L. J. Callan (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Mr. J. N. Donohew, Project Manager (w/a)

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C. 20555 l

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, Attachment page 1 of 2 Response to NRC Request for Additional Information l

Generic Letter 95-07 NRC Request - Item 1 Discuss if valves (normally open, safety-related power-operated gate valves which are closed for test or surveillance, but must return to the I open position) were included.in your review, and how potential pressure locking or thermal binding concerns were addressed.

GGNS Response As discussed in our February 13, 1996 submittal, " evaluations encompassed all system modes of operation which are within the plant's design basis.

The evaluations were completed through review of procedures,...  ;

surveillance testing ..." GGNS has sixteen normally open valves with an open safety function, but which are closed for test or surveillance (Table 1).

These valves are acceptable per the requirements of Generic Letter 95-07

'because of one or more of the following:

1 I

o Five have been, or.are scheduled to be, modified to prevent pressure I locking as discussed in GGNS's February 13, 1996 submittal.

1 o The' remaining eleven valves were evaluated for pressure locking / thermal binding during all modes of plant operation, including surveillance testing. It was determined, during this evaluation, that either the valves would be acceptable, or the valves are not required to be operable during the surveillance test. The valves not required to be l operable during surveillance testing are not relied on to function until l the system is operable per Technical Specifications.

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, _ _ _ _ . - . _ m.,.. - , - , m ._- -... .- , , _ _ _ _ _ -

mi .s-ws.,,s__ m.

s 'k Attachment page 2 of 2 NRC Request - Item 2 l

. Describe the evaluations and training for plant personnel that have been- )

or will be conducted for each valve design or procedural modification (to preclude pressure locking cnr thermal binding) to assure that the 4

modifications will not have an adverse impact on plant safety.

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.GGNS Response )

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l The valve modifications to susceptible valves, including those already  ;

l modified and those planned, involve providing a vent path from the bonnet i area back to the system piping to prevent pressure locking (Figure 1).

These modifications result in one side of the double disk performing the ,

! isolation function for the valve. l I

}. - The. loss'of one side of valve disk is considered for impact on the plant.

l To ensure that the' modifications did not, or will not, have an adverse f impact on plant safety, evaluations were performed for each of the changes  ;

in accordance with.10CFR50.59. Post modification testing, including Local

}

. Leak Rate Testing,' confirms the acceptability of the change. The fact the

i. valves would become unidirectional was considered. For example, a' manual j i

~ valveLwas added in the vent line for the HPCS injection valve that-is closed during the quarterly pump surveillance. This will prevent the i injection of water into the vessel due to disc flexing from the pump discharge pressure during performance of this test.

l All design changes, including valve modifications, are evaluated for the  :

appropriateness for training plant personnel. Those deemed appropriate are included in lesson plans or are made part of required reading.

Training on the modifications to valves to prevent pressure locking has been provided to Licensed' operators, and future modifications will be ,

reviewed for appropriateness for training. No training was performed on l

.the procedure changes, due to the minor nature and the fact it is a straight forward change in valve lineup restoration, clearly spelled out.

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TABLE 1 e

p-Valve . Number? Valve Description . [

QQW M$%qi k

512 004A RHR Pump Suppression Pool Suction isolation.

1%i%pAk%%p%' ;n M?

12E0048 % M RHR Pump Suppression Pool Suction.lsolation 4

ymu-rM.N m w m: m%r m W gin J12 004Cs"%p-'- RHR Pump Suppression Pool Suction isolation

-sn

1. Sfemr -- ($;9.J 4& r 0 a 1

F m,027A W eaehtet RHR System Shutoff Valves

, . vywpM%.b;t s 12F027B RHR System Shutoff Valves

$:&c t$ e;<ue.Yp;r m:,MW',8 w 4 e E.1.,2_F.047A wyw y S W HX Inlet isolation G i G > Q N4 W yj% 1,Lfu ,

E12F047B W M HX Inlet isolation-3My@nyn R RHR Min Flow Isolation

%;E12F06Mp:{;l1W G%Q  :

• 1 E RHR Min Flow Isolation F

g.g,12F064Bg<

ggy, %m l

<E12EOMC Y ED RHR Min Flow Isolation , n. .

%Md%%WW gF0010w@!

.;,gg a s y

.LPCS Suction LPCS Min Flow

E21F011;?$@9

gpy%Mi -

RCIC Steam Supply Drywellisolation

+ E51F063p;./p1 me;a u E51F06fd , y RCIC Steam Supply Drywell Outboard Isolation s,,- , g;p n 1

,-F E51.r.068Pi ~m ,

RCIC Turbine Exhaust to Suppression Pool isolation l s +4 . ,4 $m(Qli E51F077

+. . n nh a.

RCIC Turbine Exhaust Outboard Vacuum Breaker Isolation W'.

+h 'h Id 4 , L e

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, , FIGURE'1 l

! M CTMT l

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j C

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New Line Typical GGNS Pressure Locking Modification A

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t_______________ -. - . . . _ , _ _ , - -

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o .

, , BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION LICENSE NO. NPF-29 l

DOCKET NO. 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY and SYSTEM ENERGY RESOURCES, INC.

and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION and ENTERGY OPERATIONS, INC.

AFFIRMATION I, C. R. Hutchinson, being duly sworn, state that I am Vice President, Operations GGNS of Entergy Operations, Inc.; that on behalf of Entergy Operations, Inc.,-

System Energy Resources, Inc., and South Mississippi Electric Power Association I am authorized by Entergy Operations, Inc. to sign and file with the Nuclear Regulatory Commission, this Request for Additional Information to Generic Letter 95-07; that I signed this application as Vice President, Operations GGNS of Entergy Operations, Inc.; and that the statements made and the matters set forth therein are true and correct to the best f my owl dg6, 13(for>[htion and belief.

,. . M -

C.' R. II6tchinsori '

STATE OF MISSISSIPPI COUNTY OF CLAIBORNE SUBSCRIBED AND SWORN TO before e, a Notary blic, in and for the County and State above named, this N- day of 4(4rd , 1996.

.(SEAL) gg / /t

-. ,j '\ Noiary Public m

My commission expires:

CESISSI??! STA1UEE MOTART FITUC NY COMMISSION CIPIRES JDC 5. IM9 BONDED THRU STECldL NOT/JT IJ.EVI;S 1

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