ML20059N646

Safety Evaluation Supporting Amend 71 to License NPF-29

ML20059N646
Person / Time
Site:	Grand Gulf
Issue date:	10/09/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20059N644	List: ML20059N640 ML20059N646
References
NUDOCS 9010170075
Download: ML20059N646 (3)

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- NUCLEAR REGULATORY COMMISSION f

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iSAFETY-EVALUATION 3Y THE OFFICE OF NUCLEAR REACTOR REGULATION'.

r RELATED TO AMENDMENT NO. 71 - T0 FACILITY OPERATING' LICENSE NO.< NPF-29

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i ENTERGY OPERATIONSe INC.

GRAND GULF NUCLEAR STATION; UNIT 1 DOCKET N050-416-I i

1.0 INTR 0000 TION-

,. By. letter dated August 10, 1990, as revised August'20,;1990' the licensee.

- Entergy. Operations, Inc., requested an: amendment to: Facility. Operating l License No. NPF-29 for the Grand Gulf Nuclear. Station, Unit 1-(GGNS-1).

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Theproposed^amendmentwouldchangeftheTechnicalSpt@lanceRequiremetf

@ations(TS)by adding.a note. to TS' Table 4.8.2.1-1, " Battery Surveil to ' allow a battery charging current 11essL than 2. amps. instead of? specific-gravity limits to be'used to determine battery operability when on float-charge following a battery service or performance discharge test. The, associated Bases for the TS are also changed.

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2.0 EVALUATION 1

The existing' surveillance requirements'in TS 4.8.2.1 require, in part.

- that. engineered; safety features (ESF) batteries be: demonstrated operable o

by verifying ~ that the battery electrolyte, specific gravity meet the.

limits in Table;4.8.2.1-1 at specified test intervalss:iVerification'that the specific gravity limits are met, must be madelat least once per 7 days.

for Category A limits,-and at least once'per 92/daysifor Category B

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limits.1 In addition.. verification must be made that Category B limits,.

or allowable values, are met within 7-days after the ' battery service discharge ' test,. required by TS 4.8.2.1.d,cand af ter the battery performance discharge test,: required by TS 4.8.2.1.e.1 Although the batteries are fully recharged after?a discharge test, it takes about 7 daysifor.the specific: gravity to : stabilize. Until the J

specific gravity limits of Table 4.8.2.111 are met,.the batteries cannot' be declared. operable. The: Bases' for TS 3.8.2.1' recognize that. a battery l charging current which.has stabilized.at! allow'valuecis an' acceptable alternative to specific gravity measurement for determining the: state of.

charge of the battery..but an' acceptable value11st not.specified., The; licenseeLhas proposed a change-to TS Table.4.8.2J-liby adding a footnote to allow a; charging current less than 2 amps to be~used as an: alternate-means of' verifying,the operability of-batteries following a battery ;

service or' performance-discharge test. The footnote would be applicable--

to the Category A limits'and the Category B allowable values. The Bases e

for TS 3.8.2.1;would be changed to reflect-the TS change.

9010170075 901009 DR ADDCK 05000416 -

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The' staff. has reviewed the proposed changes to use the battery charging 1

currentiin lieu of specific' gravity to-verify the operability of ESF.

batteries following service and performance discharge tests. The d

specific gravity'o the tested battery drops during discharge to at value:

approaching 1.00.: On the subsequent recharge,.the measured specific gravity of the cells is not innediately representative of the average 1

specific gravity of the electrolyte' in the cell. :ThisL is caused by high; specific gravity sulfuric acid which sinks.to the bottom'of the cell' resulting;in an incorrect low reading at the top of the cell where a 1

L sample is taken for measurement. The high_ specific gravity acid i

p gradually ~ diffuses through the. solution and it takes about a week for the' J

acid to diffuse throughout the electrolyte.. Due to the time' required l

for the diffusion process, the specific gravity parameter measurement?

'does not. accurately-reflect the battery's state of charge after recharging.

o' During;the period following a service or. performance discharge' test,'the' 1

battery charging current is a more. accurate indicator of the battery

' a state-of charge. As.the cells; approach full charge; the battery voltage:

4 rises to approach the charger output voltage, and the charging' current-decreases to=a stabilized.value. When the charging current.has stabilized-l

at the charging voltage, the battery is charged, even thoughf the specific-

.j gravity has not stabilized. A charging current less than 2 amperes when on float charge is indicative of full charge. >This method:is-in a

accordance with IEEE Standard 450-1980, "IEEELReconnended Practices for:

Maintenance Testing and Replacement of Large Lead Storage Batteries for Generating Stations and Substations," and,is, therefore, acceptable;-

However, the use of batteryc charging l current in lieu'of. specific gravity,-

'is acceptable only for Categories A and B parameters within;7~. days following the service'and performance discharge tests. At other times,-

the specific gravity parameter must be used.

7 Based on-its review of the licensee's submittals, the staff. concludes that the proposed TS and-Bases changes to' allow the use of-the battery i

charging current,in. lieu of. elertrolyte' specific gravity to' verify operability of ESF batteries following service and performanceLdischarge-tests are in accordance with:IEEE Standard 450-1980, and are, therefore,-

3 acceptable.-

3.0. ENVIRONMENTAL' CONSIDERATION

'nis amendment involves a change in a requirement with respect:to the

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-installation or use of a facility 'componentilocated.within thel restricted.

area astdefined-in 10 CFR.Part 20 and changes the surveillance requirements.'-

The staff has determined that the amendment; involves.nofsignificantiincrease i

in the amounts, and no significant change:in the types', of any effluents-that may be released off site, and that there isino significant increase in individual or cumulative occupational radiation. exposure.---The' Commission o

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1 o has previously issuedia proposedifindingLthat this' amendment involves-no

~lsignificant hazards' consideration.. and there has' been no public comment ion j

such finding. ' Accordingly, this amendment meets:the eligibility criteria

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for categorical; exclusion set forth in 10 CFR 51.22(c)(9). : Pursuant to:

10 CFR 51.22(b), no environmental 1 1mpact statement or environmental assessment need be prepired in: connection with the issuance-of this amendnent.

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4.0 CONCLUSION

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The. Commission ~ made a proposed' determination that this amendsent. involves; 1

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no significant hazards consideration. which was published in the Federalf

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- Register on September-5,~ 1990 (55-FR =36342) and consultri with the state i

of Mississippi

. No public comments or ' requests.for hearing were received,.

L and the State of Mississppi;did.not have any comments.

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.The' staff has concluded;. based on the considerat' ions' discussed above',.

that:

(1)-there is ' reasonable assurance. that the health and safety of the' public will not be endangered by operation-in-the proposed. manner. and-.

-(2),such activities.will be conductedLin compliance:with the Commission's regulations,'and the' issuance;of this amendment'.will not be inimical to the common defense' and the security, or to the health and safety of;the-j public.

l Dated:

October 9,11990' I

Principal Contributor:

N.K. Trehan l

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