ML20034F433

Safety Evaluation Supporting Amends 56 & 35 to Licenses NPF-68 & NPF-81,respectively

ML20034F433
Person / Time
Site:	Vogtle
Issue date:	02/19/1993
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20034F430	List: ML20034F429 ML20034F433
References
REF-GTECI-070, REF-GTECI-094, REF-GTECI-NI, TASK-070, TASK-094, TASK-70, TASK-94, TASK-OR GL-90-06, GL-90-6, NUDOCS 9303030139
Download: ML20034F433 (5)

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NUCLEAR REGULATORY COMMISSION

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SAFETY EVALUATIOfJ BY THE OFFICE OF flVCLEAR REACTOR REGULATIOff i

RELATED TO AMEhDMENT t;0.56 TO FACILITY OPERATING LICENSE !JPF-68 s

Af/D AMErlDMENT f40. 35 TO FACILITY OPERATlfiG LICENSE !JPF-81 o

GEORGI A POWER COMPANL ET AL.

V0GTLE ELEClRIC GENERATIf;G PL ANT. UNITS 1 AND 2 l

i DOCKET NOS. 50-424 AfiD 50-425 4

1.0 INTRODUCTION

4 By letter dated November 18, 1991, as supplemented March 2, 1992, Georgia R er Enmean:,

et al. (the licensee), proposed license amendments to change the Iechnical Specificaticms (TSs) for the Vogtle Electric Generating Plant (Vogtle or the facility), Units 1 and 2.

The proposed changes are in response to Generic Letter (GL) 90-06, "Re: alution of Generic Issue 70, ' Power-Operated i

Relief Valve and Block Valve Reliability,' and Generic issue 94, ' Additional i

Low-Twperature Overpressure Protection for Light-Water Reactors,' Pursuant to L

10 CFR 50.54(f).

which was issued by the NRC on June 25, 1990.

A discussion of the proposed changes and the NRC staff evaluation and findings relative to

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each are addressed in section 3.0 of this Safety Evaluation.

l The licensee's earlier response to GL 90-06 dated December 20, 1990, also l

nrovided specific commitments regarding the GL 90-06 recommendations for j

quality assurance, maintenance, and testing of the power-operatered relief

<alves (PORVs) and block valves.

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2.0 BACKGROUND

Generic Letter 90-05 represents the technical resolution of two generic issues and includes changes which are safety enhancements.

Generic issue 70, " Power-Operated Relief Valve and Block Valve Reliability," involves the evaluation of the reliability of PORVs and block valves and their safety significance in PWR

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plants The generic letter discussed how PORVs are increasingly being relied l

on to perform safety-related functions and the corresponding need to improve the reliability of both PORVs and their associated block valves.

Proposed j

.,taff pLsitions and improvements to the plant's TS were recommended to be i

i plemented at all affected facilities.

Generic issue 94, " Additional Low-Temperature Overpressure protection for Light-Water Peactors," addresses concerns with the implementation of the requirements set forth in the resolution of Unresolved Safety Issue (US A-26 " Reactor Vessel Pressure Transient Protection (Overpressure Protection).."

The generic letter discussed the continuing occurrence of overpressure events and the need to further restrict the allowed outage time for a low-temperature overpressure protection channel in operating modes 4, 5, and 6.

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3.0 E"M Un i 10f; s

9 2.1 Lerwric issua 70 3

In response to Generic Issue 70, the licensee proposed changes to TS 3/4.4.4, "Pelief Valves,' that require power to be maintained to the associated block calves v. hen closed, and to plate the PORVs in manual control when the block

,-alves are not operable.

Other changes are editorial and are proposed to eetter agree with the rodel 15 in Gt 90-06.

Speci fically, the proposed a" and ent s v.ould change t he following port t ons of TS 3.4.4.:

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in tho i 11it ing Londit ton Tor Operat ion (LCO) statement, change " All

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. w e-arerated relief valves to " Bath power-operated relief valves i

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'n ^ ti : 5t2trnent a change 'With one or nore PORV(s) ino;terable s

tc With one or both PORV(s) inoperable.

Also, change "

or close the aszciated block valve (s)" to or close the associated bloc' al;e(s)..'ith ra.er maintained to block valve (s)."

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'r " ticn : ate m et b. change "With one or care PORV(s) inoperable f

to 'Litr w or bot h DORV(s) inoperahie i

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nt b.2. thange 'With no PORVs OPERABLE to "With l

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iO In Act ic. M ate ent c, replace the existing statement witn the folle;ing:

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"lith one v Wh block calve (s) inoperable, nthin I hour restore.he l

Dlock vals=(s) to OPERABLE status or place its associated PORV(s) in w ual control.

Restore at least one block valve '

OPERABLE status itthin the next hour if both block valves are inop. able; restor < anc

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craining inuperable block valve to OPEPABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; m Hrc i se to in at least HOT STAfiDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and 'n HOT G N ;!!hin the f nllowing 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> '

f aie 3i4.4.4 to include the following:

The PORV(s)

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<t u-f ;ith automatic actuation circuitry and manual control 1

a ;.c Na credit is taken for accident mitigation by autoTatic PORV opc otten in tho analyses f or 110DE 1. ?. and 3 transients.

The PORV(s)

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nsider m GPERABLE in either the canual or automatic mode.

The i

autr-atic r M e is the preferred configuration since pressure relieving

r. a p ab i l ii;f i< provided without reliar-on operator action."

Tho IP st af f hn reviewed the lic ensee's proposed modifications to the Vogtle Is

. "tb prupased codifications are consistent with the staff's

.t at ed in the generic let ter, the staf f finds the prnoon.

v it im m dif~

_ eptab!(.

The staff also finds that the specific cu it 93ct ry quality assurance. raintenance, and testing of the PORVs n ! bin '-

11-n e. w si; tent with the GL and, therefore, are acceptable.

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Eneric Issue 94 l

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l h response to Generic issue 94, the licensee proposed changes to 15 3.4.9.3.

" Cold Oveipressure Protection Systems." The first is an editorial change to relocate the depressurizing of the reactor coolant system (RCS) through.: RCS I

, =n t fru" : tate -nt c of the LCO to the initial LCO statement.

The new act ion staterent t e;ould allow the combination of one residual heat removal CHR) action relief valve (SRV) and one PORV to be used for cold overpressure protectice The action statement proposed for Modes 5 and 6 would decrease j

th" a l l e.s ed out-of-wrvice tire (A01) from 7 days to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with only one calve available to provide cold overpressuro protection.

Specifically, the l

pec; d awndmti. ould change the fol!aaing partions of 15 3.4.9.3:

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1; In t v LEO statement, change "At least one of the folluaing Cold I

+ m p, _...u n Protection Systems shall be OPERACLE:" to "At least one f olla /ing groups o'f Cold Overpressure Protection Devites l

of

e A 11' bo PERTULE whan the reactor coolant system (RCS) is not po unrel threugh a vent path capaDie of relieving at 1"ast 670

-l 10-

. ate fl% at 470 psig."

(This statement for the vent path war ref u te! fn Ltd statenent c.)

(2) in

'r' clote _nt c, change "The Reactor Coolant System (RCS) l I

cepco c un zed.ith an RCS vent capable of relieving at least 670 gpn wi'er fle; at 470 psig.' to "One RHR SRV and one PORV witn setpoint' 1s det.cribod above."

i p) in,cticn 5tatrrent a. change "With one PORV and one RHR suction j

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/'l t inoperable, either restore tv;o PORVs or tv;o RHR suc tion

.ellei val.

to GPEE AULE status within 7 days or depressurize and t ! ~ IN " u specified in Specification 3.4.9.3.c above, althin

'>t EF o.

to 'In Mode 4, with only one PORV or one RHP SRV F e'.

s t or-2 additional valve to OP!RABLE status tithin +he l

nmt ' day; o u,ressurize and vent the RCS, as specified in 3.. 9. 3 at'o s within the next 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.'

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, d ion Statement b which states, "In MODES 5 and 5, with

• 1' nt PDRV or one RHR SRV OPERABLE, restore one additional valve A ERAELf atatus within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or depressurize and vent it. LC5, as specified in 3.4.9.3 above, within the next 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />."

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• ute i he t m rent Act ion St aterent b to Action Statement c.

C h a up>

l 1*h both PUR6 and both RHR suction relief valves ino;;erable, M r: sm ize and,ent the RCS as specified in Specification 3.4.9.3.c.

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ithh E hours.' to "In MODES 4, 5, or 6 with none of the PORVs or im s ? OPi % LE, depressurize and vent the RCS as specified in 3.4.9.3 d hU ii il t h iri t he neXl 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. "

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Penu~ter Action Statement c as Action Statement d, and change "In t he event either the PORVs, the RHR suction relief valves, or the RCS sent(s) are used

. " to "In the event that the PORVs and/or RHR SPVs. or

• RC5 vent (s) are used a

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(7)

Renumber Action Statement d as Action Statement e.

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Change TS Bases under " Cold Overpressure Protection Systems" (page B 3/4 4-16) by replacing the first paragraph with the following i

The OPERABILITY of two PORVs, two RHR suction relief calves, a PORV and RHR SRV, or an RCS vent capable of l

relieving at least 670 gpm water flow at 470 psig ensures j

that the RCS will be protected from pressure transients which could exceed the limits of Appendix G to 10 CFR Part 50 whon ene or more of the RCS cold legs are less than or equal to 350 degrees F.

The PORVs have adequate reliesing i

capability to protect the RCS from overpressurization when the transient is limited to either.

(1) the start of an q

idle RCP with the secondary water temperature of the steam generator less than or equal to 50 degrees F. above the RCS cold leg terperatures, or (2) the start of all three charging pumps and subsequent injection into a water-solid RCS.

The RHR SRVs have adequate relieving capability to protect the RCS from nyerpressurization when tne transient i

is l mited to either (1) the start of an idle RCP with

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the secondary to ;)rimary water temperature difference of i

the steam generator less than or equal to 25 degrees T. at i

n RLS temperature of 350 degrees F. and varies linearly l

to 50 degrees F. at an RCS temperature of 200 degree f j

or less, or (2) the start of all three charging pumps and t

subsequent injection into a water-solid RCS, A

l combination of a PORV and a RHR SRV also provides 1

overpressure protection for the RC3, I

Also rc eise the second paragraph of this Bases by changing " Operation

, it h a PORV setroint less than or equal to the maximum setpoint ensures that the nn inal 16 [FPY Appendix G reactor vessel NDI limits tu

" Operation lith a PORV setpoint less than or equal to the vaxinur.

etpo:nt ensures that the nominal 13 EFPY for Unit I and 16 EfPf for Unit 2 Appendi, G reac tor vessel hDT limits IM st af f on r e. iewed the licenseis proposuJ modifications to the Vogtle S n.ce the proposed modifications are consist ent with the staf f's l

pos:tir n previouslj stated in the generic letter,.he staff finds the proposed d

' 1:fintionr to b.

acceptable.

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4.0 STATE TONSUliATION in accordarce with the Comission's regulations, the Georgia State official 1

'as notified of the proposed issuance of the amendments, lhe State of ficial baj no w ents.

l 5.0 ENVIPZ"f MlM LONS!DIRAT ION I

The te d ents change surveillance requirements.

The NRC staff has determined 4

that the a,entents involve no significant increase in the amount s, and no

4 r significant char.ge in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative ocu.patienal radiation exposure.

The _ammission has previously issued a proposed finding that the amend: rents involve no significant hazards con-ideration. and there has been no public coment on such finding (57 iR 3:5S5 and E7 TR 34587 both dated August 5, 1992).

Accordingly, the arendments i

'2t ihr elmibility criteria for categorical exclusion set forth in 10 G R l

51.22(c)(9).

Pursuant to 10 CFR 51.22(b) no environmental impact staterent or l

avit or : _-tal assessnent need be prepared in connection with the issuance of i

the n ee n t <.

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6.0 (P KlUSION j

The r o":iisicn has concluded, based on the considerations discussed aba.+

I that (1) there it reasonable assurance that the health and safety of the f

oblit U 1I not !e endangered by operation in the proposed 'anner, (2) uth ctivitir

l l l tm conducted in compliance with th+ Connission', regulati;ns

': 1 (3 ) 111 i:- su nte of t he c:endment s. ill not be inimical t o fim ct on d>fcn;e m 3ecurit', or to the health and safety of the public, i

1 Wi - h d r mtrabuters D. Hood J. Harold in t i February 19, 1993 l

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