ML20096B886

Application for Amend to License NPF-29,changing TS Re Primary Containment Penetration Conductor Overcurrent Protective Devices,Under Exigent Circumstances,Per Generic Ltr 89-10

ML20096B886
Person / Time
Site:	Grand Gulf
Issue date:	05/06/1992
From:	Cottle W ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20096B890	List: ML20096B886 ML20096B895
References
GL-89-10, GNRO-92-00053, GNRO-92-53, NUDOCS 9205130023
Download: ML20096B886 (7)

Text

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, e Entergy Operations, lac.

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W. T. Cottle L

May 6, 1992 " -

U.S. Nuclear Regulatory Commission Mail Station P1-137 Washington, D.C. 20555 Attention: Document Control Oesk

Subject:

Grand Gulf Nuclect Station Unit 1 Docket No. 50-416 License No. NPF-29 Primary Containment Penet ration Conductor Overcurrent Protective Dev. ices Technical Specification Change Under Exigent Circumstances Proposed Amendnwr to the Operating License (PCOL-92/04)

GNRO-92/00053 Gentlemen:

By this letter, Entergy Operations, Inc. is requesting a change to the Grand Gulf Nuclear Station (CGNS) Technical Specifications (TS) under exigent circumstances. The change would increase the trip setpoints of four circuit breakers for the Suppression Poel Makeup (SPMU) valves.

On March 29, 1992, during the- review of motor-operated valves in accordance with Generic Lotter 89-10, ggt:S detern:ined that the actuators for t he GPMU dump-valves woro undersized. This could result in a t orque up to 2007, of rated on the actuator. During startup testieg these act uators 1 ad been overtorqued several times. I.imitorque states that the actuators ar e capable of surviving a one time overtorque of-two times the rated torque without sacrifice to the actuator qualificat ion. The overtorqued act uators were replaced with identical actuators already onsite that had never been overtorqued. Since the valves are only required to stroke open one time to per form their safety function, continued operation until the current refueling outage was justified.

Additionally, a design change was initiated to replace these actuators with properly-sized actuators during the current refueling outage which began April 17, 1992. During the design change procnss, it was determined that the larger valve actuator motors would requite circuit breakers with higher trip setpoints. These trip secpoints are located In TS Table 3.8.4.1-1.

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9205130023 920506 PDR ADOCK 05000416 [f7M P PDR

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May-6,(1992, GNRO-92/00053 Page 2 of 3 l

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The SPMU system and the associated circuit breakota are required Operable in Operational Conditions 1, 2 and 3. After the replacement of the actuators and the associated circuit bre,akers, t:GNS will be unable to start up until the trip setpoint values in the table are changed to reflect the higher' values. Allowing for the standard 30-day Federal Register notice would delay approval of the requested change.beyond the scheduled end of the current refueling outage. This is the basis for requesting an expedited TS amendment.

In accordance with the provis ions of 10CFR50.4, the signed original of the requested amendment is enclose.l. Attachment 2 provides the discussion and technical justification to support the requested amendment. Attachment-3 is a copy-of the affected TS pages, marked up to show the requested change.

This-proposed amendment has been reviewed and accepted by the Plant Safety Review Committee and the Safety Review Committee.

Based on the guidelines presented in 10CFR50.92, Entergy Operations has concluded that this proposed anendment involves no significant hazards considerations.

Yours truly, w r~'e m n WTC/BSF/mtc attachments:-1. Affirmation per 10CFR50.30

2. GGNS PCOL-92/04

3. Mark-up of Af f ected Technical Specification Pages

4. Sample Proposed . -.tnical Specification Pages cc: Mr. D. C. Hintz (w/a)

Mr. J. L. Mathis (w/a)

Mr. R. - B. McGehec (w/a)

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

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

.Mr. Stewart D. Ebneter (w/a)

Regional Administrator U.S. Nuclear. Regulatory Commission Region II 101 Marietta-St., N.W., Suite 2900 Atlanta, Georgia- 30323 Mr.- P. W. O'Connor, Project Manager (w/2)

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission-Mail Stop 13113 Washington, D.C. 20555 l

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PETORE Tile UNIE D STATES NUCLEAR REGULATORY COMMISSION 1.lCENSE NO. NPI--29 DOCKET NO. 50 416 IN Tile MATTER OF HISSISSIPPI POWER 4 LIGilT COMPANY and SYSTEM ENERGY RESOURCES, INC.

and SOUTil MISSISSIPPI ELECTRIC POWER ASSOCI ATION and ENTECGY OPERATIONS. INC.

MTIRMATION 1, W. T. Cottle, being duly sworn, state Llu.t I am Vice President ,

Operations GGNS of Entergy Operations, Inc. ; that on behalf of Entergy Operations, Inc., System Energy Retources. Int., at.d South Mississippi Electric Power Association am authorized by Ent argy Operations, Inc.

to sign and filo with thn Nocinar Regulat.ory Commirsion, this appifcation for emendment of the Opotating Licenso of the Grand .';ulf Nucicar Stat lon; that I signed this application as Vice President, Operations GGNS of Entergy Operations, Inc.; anri that_ the statements made and the matters sot forth therein are true and correct to the best of my knowledge, informa fon and beller.

_ w r dessa:-

W. T. Cottle STATE OF MISSISSIPPI COUNTY OF CLAIBORNE SUP,8CRIBED AND SWORN TO before me, a Notary Public, in and for the County

. and Stat.o above named, this h day of  %% , 1992.

(SEAL) h n. 4D h -

Notary Pul { ]

My commissica expires:

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Attachment 1 to GNRO-92/00053 Page 1 of 4

1. e t

A. Subject; PC0!c9 b04, Primary Containment Penetration Conductor Overcurrent Protective Devices Technical Spr,2fication (TS) Change Under Exigent Circumstances TS Tablo 3.8.4.1-1

- Affected Pages: 3/4 6-29 and 3/4 8-36 B. DISCUSSION AhU JUST1FICATION:

UFSAR Sectis,- 6.2.7 describes the Supptession Pool Makeup (SPMU) system and applicablo 'rcnsient and accident analysos. The SPMU system consista of two 100% su bystems, whero each is capable of dumping the makeup voluno frcm the upper containment pool to the suppression pon1 by grevi y flow. The SPMU system consists of two 30" t

Ifnes which penetratu tha separator and of the upper containment pool through the side walls. The lines, are routed down to the supprossion pool on opposit o .didon of the steam tunnel. Each SPMU line has two  :

normally-closed motor-operated but terfly valvos in series. The valvos in oat.h lino are of-the'usmo electrical division. '

The safety function of the SPMU system is to transfer water from the ,

upper containment pool to the suppression pool af ter a Loss of Coolant Accident (LOCA). The upper pool makeup volumn is dumped by gravity ,

flow after opening tl.o twa normally-closed val /es in series in each lino. The SPMU system is automatically initiated 30 minutos after a LOCA is detected or on low-low supp.= ision pool water level following a LOCA. It can also be manually initiated provided a LOCA signal is present.

In accordance with Generic Lotter 89-10, GGNS has continued ef forts to ,

establish the required torquos/ thrusts to open and closo  !

safet.y-related motor-operated valvos with design differentlal pressures _and flow ratos. Based-on this ovaluation. -it was determined -

that-the actual maximum ialculated flow through the SPMU valves and the required torques are higher than assumni 'In the initfal design

_ calculations and, therefore valvo stress levels would bo. higher than previously assumed. It was also determined that during startup

• testing thoso actuatora had boon overtorqued soveral times.

- As a result of the deficiency, the actunt. ors wore toplaced with identical actuators already onsite. Concurrently, the actuators that had been removed were dinassembled and the goaiing wan inspected in accordance with the recommendations of Limitorque. No cracks or excessive wear woro found in any of the actuators; thoroforo, it was concluded,> based on=the'. inspection results, that the actuators woro '

capablo of performing their design safety function.

GGNS decided to replace the undersized actuators with actuators that.

are properly sized-for the application. During the design-chango process .it was determined that, to support the larger. actuators, f

- circuit' breakers with highor trip sotpoints would be required., The '

circuitL breakers and.the associated trip sotpoints are located in 'IS Tablo 3.8.4.1-1. Thorofore, a TS change is required for this modification.

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Attachment 1 to GNRO-92/00053 Pnge 2 of 4 This proposed amendment t o the Ornnd Gulf Nuclear Statinn (CGNS) TS requests changes t o TS Table 3.8.4.1-1, Primary Cont ainment Penetration Cominctor Overcurrent Protective Devices. The proposed -

change would reviso the trip setpoints of four circuit brenkers (52-1521-07, 52-1521-44, 52-1641-35 nnd 52-1641-36) from 10 nmperes to 32 amperes.

The mod /fications being mnde will restore the the reliability of the SPHU systeu by providing acturitors which are capahlo of delivering the torque required to stroke t he valves against the design differential pressure and flow rate, following a LOCA, without exceeding tho act uator manufacturer's design torque rating for t he act uators.

Tho replacement of the overcurrent protective devices to account for the larger valvo actuator motors ensures that the equipment will operate without inadvertent actuation of the protective devices.

Spurious fcip avoidanco for these deviers is based on ths valvo ,

actuator motors' inrush carrent ns well ns the valve st oke times and  ;

motor running currents. The proposed trip setpolo a are high enoagh l to prevont spurious tripping of the brenkers while iroviding protection of the ponctrat ions in accordance with the guidanco of Regulatory Guide 1.63, Revision 0. Proper coordination in maintained between the primary and trackup penetration ovnrcurrent. protection and the penetration conductors.

'tha Bases for TS 3/4.6.3 also address the fact t'nat the SPMU system [

initiation logic is bypassed when the reactor modo switch le in tho i REFUEh positton. This design change makes no changes to the SPMU  ;

system initiation logic. The adequacy of protection of primary  ;

containmen* electrical penetrations and penetration conductors an addressed by Bases for TS 3/4.B.4 w.(11 not be affected by the ,

m >dificat ion. The chango to the overcurrent protective device trip l setpoint will ensure that proper coordination is maintained for equipment operation and p;otect.fon.

1 C. NO SIGNIFICANT IIAZARDS CONSIDERATIONS

1. Entergy Operations, Inc. is proposing the revision of the t rip i setpoints for four breakers on Technical Specification Table 3.P. 4.1-1, Primary Containment Conductor Overcurrent-Protectivo Devices.

2. The Commission has provided standards for determining whether a no significant. hazards consideration exists as stated in ,

10CFR50.92(c). A proposed amendment to.nn operatini, license .

involves no signific+,nt hazards consideration if operation of tho facility in accordanc e with thec proposed amendment would not t (1) involve a significant increase in the probability or consequences of an accident previously evaluat ed; or (2) create the possibility of .a new or dif fereur kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a ,

margin of safety.

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I Attachment I to GNRO-92/00053 l page 3 of 4

3. Entergy Operations hos evaluated the no significant hazards considerations in its request for a license amendment. In i accordance with 10CFR50.91(a), Entergy Operations is providing the analysis of the proponed mendment against the three standards in 10CFR50.92:

a. No significant increase in the probability or consequences of' an accident previously evaluated Insults from this chango..

Tho breakers for which tho trip setpoints are requested to be l changed are addressed in Technical Specificat. ion 3.8.4.1 as }

primary containment penntration conductor overcurrent protective devices. The Suppression pool Makeup (SpHU) 9ystem initiat.lon logic will not be affected by this change.

The breakers currently installed are to bn replaced with breakers sized to account for the increased sizo of the valve actuator motors to be installed.

The replacement of the overcurrent. protect (ve devices to account fer the larger valve actuator motors ensures that the equipment will operate without inadvertent actuation of the protectivo devices. Spurious t rip avoidanco for these devices is based on thn valvo act.uator motorr.' inrush current i as well as valyn stroke times cnd actor running currents.

The proposed trip sotpoints are high enough to provent spurious tripping of the breakers while providing protection of the penntrattons in accordance with the guidance of Regulatory Guide 1.63, Revision 0. _ proper coordination is maintained betwoon the primary-and backup penetration overcurrent protection and the penetration conductors.

Tho increaand lond placed by the larger valvn actuator motor has been evaluat.ed and found to have no adverse impact on the 61octrical distiibut.fon system.

Based on the aoovo analysis increasing the t.tip setpoints for those breakers will not significantly increase the probability or consequences of a previously analyznd accident.-

b. The chango would not creatn the possibility of a new or

' dif forent kind of accident from any previously analyzed.

I y The replacement of the osorcurrent protective devices to account for the: larger valvo actuator motors ensures that the equipment will operate without. Anadvertent actuation of the protectivo. devices. Spurious t rip avoidance for these

'c devices is' based on the valvo actuator inotors' inrush current

l. as well as valvo stroke times and motor running currents.

The proposed trip setpoints are high enough to prevent spurious tripping of the breakers while providing protection of the penetrations in accordance with-the guidance of

l. Regulatory Guide .l.63, Revision O. proper coordination is l-int.ained between the primary and backup penetration 4 overcurrent protection and the penetration conductots.

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l Attachment 1 to GNRO-97/0005'l Pago 4 of 4 The Suppression Pool Hakeup (SPMU) systern initiation logic will not be affneted by this change. Therefore, operating

, the plant with the proposed change will not create the possibility of a new or dif ferent kind of accident from any accident. previously evaluated.

c. This changn would not involve a significant reduction in the margin of safety.

Implementation of this change to the breakers' trip setpoint will not reduce t.he margin of safety as defined in the basis for any technical specification. The Banca for Technical Specification 2/4.6.3 address the function and operability requiremnnts of the SPMU system. The modifications being mado will enhance the reliability of the SPMU system by  ;

providf ag actuators which ato capabic of delivering the i torque required to strokn t he valves against the design differential prnssure and flow rate, follot. lng a Lor.s of ,

Coolant. Accident (LOCA), without. exceeding t he actuator  !

manufacturnr's design torque rating for the actuators. '

The Bases for Technical ' pacification 3/4.6.3 also address  !

the fact that the SpHU system initiation logic in bypassed when the reactor modo switch is in thn RF. FUEL position. This design change makes no changes to the SPMU system initiation

-logic. The adequacy of protection of primary containment elect rical penetrations and penetration conductors as  ;

addressed by Bases for Technical Specification 3/4.8.4 will not be af fected by -the modification. The chango to the- ,

overcurrent protectivo device trip setpoint will ensure that  !

proper coordination is maintain 3d for equipment operat ion and-protection.

Thnrefore. these modifications will not reduce the margin of safety an defined in the basis for any technical ,

specification.

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4. Based on the above evaluat.fon, operation'in accordance with the '

proposed amendment involves no significant hazards considorations.

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