ML20073F750

Interim Deficiency Rept DER 83-11 Re Exide Battery Leak or Corrosion at Terminals Due to Cracking of Plastic Seal Covers.Initially Reported on 830228.Bechtel Communicating W/Exide to Resolve Condition.Final Rept Expected by 830614

ML20073F750
Person / Time
Site:	Palo Verde
Issue date:	03/24/1983
From:	Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Sternberg D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, ANPP-23348-BSK, DER-83-11, NUDOCS 8304150534
Download: ML20073F750 (7)

Text

Docket No. 50-528/529/530 "9

7:

50.55(e) Report p, \\2 y 2Wona Public Service Company r

r p 6@ "O P O. BOX 21666 e PHOENIX, ARIZONA 85036

\\;s-March 24, 1983 7 ;,C '

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ANPP-23348-BSK/RQT l

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U. S. Nuclear Regulatory Commission l

Region V Creekside Oaks Office Park 1450 Maria Lane - Suite 210 Walnut Creek, CA 94596-5368 Attention: Mr. D. M. Sternberg, Chief Reactor Projects Branch 1

Subject:

Interim Report - DER 83-11 A 50.55(e) Potentially Reportable Deficiency Relating to Exide Batteries May Leak or Corrode at Terminals Due to Cracking of Plastic Seals / Covers File: 83-019-026; D.4.33.2

Reference:

Telephone Conversation between A. D'Angelo and G. Duckworth on February 28, 1983

Dear Sir:

The NRC was notified of a potentially reportable deficiency in the referenced telephone conversation. At that time, it was estimated that a determination of reportability would be made within thirty (30) days.

1 Due to the extensive investigation and evaluation required, an Interim Report is attached.

It is now expected that this information will be l

finalized by June 14, 1983, at which time a complete report will be l

submitted.

I Very truly y r,

QJLL n

E. E. Van Brunt, Jr.

APS Vice President, Nuclear Projects ANPP Project Director EEVB/RQT:wp Attachment cc: See Attached Page 2 I'JO4150534 Ba<.t 24 PDR ADOCK 050M 528 l

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4 U. S. Nuclear Regulatory Commission Page Two 4

i ANPP-23348-RQT/BSK cc: Richard DeYoung, Director Office.of Inspection and Enforcement U. S. Nuclear Regulatory Commission l

Washington, D. C. 20555 T. G. Woods, Jr.

G. C. Andognini J. A. Roedel D. B. Fasnacht A. C. Rogers B. S. Kaplan W. E. Ide i

i J. Vorees J. R. Bynum D. D. Green P. P. Klute A. C. Gehr 4

i W. J. Stubblefield W. G. Bingham R. L. Patterson R. W. Welcher R. M. Grant i

D. R. Hawkinson L. E. Vorderbrueggen G. A. Florelli i

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l INTERIM REPORT - DER 83-11 l

POTENTIAL REPORTABLE DEFICIENCY l

ARIZONA PUBLIC SERVICE COMPANY (APS) l PVNGS UNIT

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I.

Potential Problem G-cell Batteries supplied by Exide have been detennined by the supplier to be potentially deficient (see attached notice).

Existing stresses could cause certain plastic components, which combine to form the seal around the terminal posts, to crack, allowing leakage of battery acid.

Additional stresses resulting from nodular corrosion could lead to radial cracks in the cell cover.

These batteries are located in the Class IE 125V DC Power System, which distributes power to plant protection and engineered safety features equipment.

II. Approach To and Status of Proposed Resolution Bechtel Engineering is currently corresponding with Exide to disposition the condition.

III. Projected Completion of Corrective Action and Submittal of the Final Report Evaluation of this condition and submittal of the Final Report is forecast to be completed by June 14, 1983.

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O EXIDE

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NOTICE TO OPERATORS OF EXIDE GN CLASS lE BATTERIES 1.

MINOR FAULTS DISCOVERED Two minor faults have been discovered by EXIDE in G-cells produced before August These faults may be present on some or all GN batteries qualified for Class lE service, even though, in most cases, there may be no visible evidence of 1932.

While the faults will not affect the safety or the perfomance of the faults.

the battery, at least in its early years of life, EXIDE believes it is prudent to effect an on-site correction as soon as reasonably possible, to pre-empt any hazard from developing.

2.

THE FIRST FAULT The fault centers aroand the teminal post seals and the components and materials which combine to make the seals.

The design of the seal (see Fig.1) involves the compression of a rubber sleeve, or gland, against the lead teminal post. The gland is held in compression by the cover and the seal nut.

Unfortunately, the stress on these plastic components, over a period of years, can cause thee to crack. The plastic boss at the base of the seal can crack as shown

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in Fig. 2, or the seal nut can crack as shown in Fig. 3.

The effect of either type of cracking is the same in that it relieves the pressure i

on the gland, thereby allowing the seal to " leak", that is, to allow acid to Given that the intercell connectors are tight, as migrate slowly up the posts.

they should be, this leakage should cause no problems.

A procedure has been developed for pemanent repair, which is now being refined, This can be and submitted for qualification, for reducing the rate of the leakage.

carried out on site by EXIDE personnel, and should be implemented during your next j

plan.ed shutdown.

It is based on the principle of eliminating all stresses on the plastic parts, and j

creating a new seal, of stress-free design, above the old seal location.

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3.

SECOND FAULT l!

The cracking of the plastic boss or nut, if complete, causes nothing more than If the cracking is only leakage, which, as stated, can be reduced by other means.

partial, or the compression of the gland is marginal to begin with, then a secondary This corrosion takes fault, called " nodular corrosion" of the lead post can occur.

place in the crevice of a partially tight seal and causes a growth to take place on the surface of the lead.

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,c Page 2 NOTICE TO OPERATORS OF EXIDE GN CLASS lE BATTERIES

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e Nodular corrosion does not take place in the presence of acid and is, therefore, avoided if the seal " leaks" slightly.

1 The consequence of nodular corrosion is to create additional stress on the pl components, this time in a radial direction.A small number of cells have been reporte 4

in the cell cover (Fig. 4).

condition.

i 4.

CORRECTIVE ACTIONS A) HOLDING POSITION Until such time as we can effect pent.anent repairs, which we plan to do using EXIDE personnel supervised by Headquarter's Enginee They should be Taken together, they will ensure integrity of the battery.

carried out expediently.

Back off all red and black nuts to eliminate any remaining gasket com-1.

pression of the post seals.

Retorque intercell connector bolts to 250 in. lbs.

2.

Ensure that terminals are fully coated with No-oxide grease.

Repair any cracks in the covers with approved cement, after appropriate 3.

4.

cleaning and neutralizing. Conduct micro-ohmeter check on all intercell con I

this check to be repeated quarterly by EXIDE personnel or until p 5.

repairs have been completed.to 250 in.1bs. as well as a thorough and d covers for further cracks.

This procedure will not affect our qualification.

NOTE:

I B) PERMANENT REPAIRS During shutdown,effect permanent repairs as follows:

.j j Disconnect and remove all intercell, intertier and terminal connectors.

1.

Remove all red and black terminal seal plastic nuts.

2.

Remove rubber glands from inside the seals.

Rebuild the seals using "0" rings with liquid sealing compound and new 3.

4.

red and black caps.

Clean connectors and terminal posts and reassemble hardware in accordance 5.

with instructions including micro-ohmeter readings.

6.

Return the battery to service.

This procedure will not only correct the primary fault, by reducing stress, will also correct the secondary fault if it exists.

will be " quenched" if allowed exposure to the acid in the cell.

I The permanent repairs cannot be undertaken until we have completed the NOTE:

re-qualification of the liquid seal planned for July 1983.

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Page 3 NOTICE TO OPERATORS OF EXIDE GN CLASS lE BATTERIES I

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C) i A final corrective action, necessary only for the few units which have radial i

This relatively simple cracks in the covers, is a " flood-pour" cover repair.

technique creates an all-enveloping secondary cover above the old one, The flood pour technique should be used only if many l

sealing off any cracks.For small, isolated cracks, individual repair is prefereable.

i cracks are present.

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1 W. E. M. Jones. Jr.

Vice President Engineering WEKJ:jeb 1

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