ML20084B456

Failure Analysis,Cracked Containers,Lead-Acid Storage Batteries

ML20084B456
Person / Time
Site:	Byron, Braidwood, 05000000
Issue date:	04/10/1984
From:	Deshpande S, Hopewell R, Kreutzfeldt R GNB, INC. (FORMERLY GNB BATTERIES, INC.)
To:
Shared Package
ML20084B451	List: ML20084B448 ML20084B456
References
NUDOCS 8404260228
Download: ML20084B456 (5)

Text

{{#Wiki_filter:,- a GN: 1 1 k. FAILURE ANALYSIS CRACKED CONTAINERS LEAD-ACID STORAGE BATTERIES BYRON AND BRAIDWOOD NUCLEAR POWER STATIONS COMMONWEALTH EDISON COMPANY

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i Prepared By: , D i R.W. HopeweU1 Reviewed By:

--                 ,7         R. L. - KreutzMfdt Approved By:                     fM S.L. Deshpinde-j, &

8404260228 840410

                ' PDR ADOCK 050004S4
      . ~ . . S.                     PDR   .,,--

i On October 19, 1983, M.A. Todd and Mark Stohr of Janes Power Systems performed a visual inspection of six (6) sets of batteries in service at the Commonwealth Edison Nuclear Power Station at Byron Illinois. Those batteries examined and their findings were as follows:

1. Unit #1 - 250 Volt Battery ll6-NCX-1500 S/N KHF-1797 New 8/80 '

There were 20 cells out of 116 that had cracked containers in the area of the j ar-cover j uncture. No cracks in the middle side walls or bottoms of any containers.

2. Security Battery Room Elevation 426 58 NCX-1350 S/N ? New 4/83 No container cracks found. Battery was on rack, but not yet connected.

3. Unit #2 East End - Class IE Room 211 58-NCX-1200 S/N KJE-971F New 9/79 No cracked containers observed. ...

4. Unit #2 West End - Class-IE Room 212 NCX-1200 S/N- KJE-9070H New 9/79 No cracked containers observed'.

5. Unit'#1 Room 111-58-NCX-1200 S/N KJE-973E New 9/79

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                   -3'~ cells outzof-58 with cracked containers.- Here again cracks were l'imited to the-jar-cover' juncture area'only.
            '6. Unit #1-                       SRoom 112.

58-NCX-1200- 'S/N KJE-972D New 9/79 No' cracked containers observer;. , From'the foregoing,~itican be_seen'that;only'two batteries-(Item'#1

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and: #2) were -observed 'to have'eracked' containers,-with cracks being concentrated in the jar-coverJjuncture area. InlFebruary,: Sales / Marketing ~ advised thatosample=cjars'from eachl

            ;of'the<batteriesi-exhibiting l cracks were.being-returned'to.~my; attention 1for-ffailure-cause analysis.

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The samples were received and examined by myself and others here at Langhorne. In the absence of the elements and cell covers, most of any meaningful evidence was missing. On Friday, March 2nd, Ramesh Desai and myself visited the Byron Nuclear Station at Byron, Illinois accompanied by Mark Stohr of Janes Power Systems. Mark Stohr had advised the week before, that Byron Station had j ust reported three cracked con-tainers on NCX-1200 type. Prior to this, the cracked containers had-been restricted to the Braidwood station. Site visitation was opted ~for in order to see first hand all available evidence prior to any container and cover replacement. We met with Art Deming, Construction-Supervisor and Doug Kruger, Technical ~ Staff. We then' examined a 58-NCX-1200 New 9/79 S/N KJE: 967 in Room 212. Cells #3 and 4 were found removed from the string, setting on a four wheel hand truck in the battery room. It was noted that on all-four jar wall faces, there was a vary-ing degree ~of etching of the jar material ~with accompanying radial. cracking.

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Mr.-Deming's first comment was "the acid-from the cell was attacking

                 - the spacer material between cells and was, in turn attacking the
                         ~
                .containe'rs".                                                                       <

InLa'ddition to the etching of: the side walls, there were also crescent shaped . cracks ' at ,the j ar-cover j uncture almost' identical-in pattern-observed on the' samples sent to me from thefBraidwood Station.- CloserTexamination of Cell #3 and #4 disclosed an extensive mottled. or etching-pattern on the entire cover. surfaces. I; asked' Art;Deming what'was useduto: clean: cells and he replied- -

                 "nothing.but ~ clear water".
                =I"indicatedithat there appeared'to-have'been"some type ofesolvent
                ' attack and'again asked.what' types'.of materials-maylhave1been used.
                ~ Finally,. itivas revealedEthat Edison Cleaner was used to. -clean
                ' inter 4 cell ~ connectors?of?No-ox-id'"A" Grease.. -The' contention,1
                --however, was that this;cleanerowas: onlyfused in.'the shop and not; s:          :on the.~ battery.

( I, a ske'ditol have -- the cleaning ~ material Ebrouglite to the- battery:- room.- LMr.TDeminglagreed(to have-the. material broughtJ toiusJfor examination.'

                <While awaiting.itsfarrival, all cell coversson the. remaining-'55

cells!were: examined (closely;andLit was; observed thatLalmostgevery(

Leoverihad. varying ^ degrees (of' etching-orimottling.- . >: 4 ..-{- i s

                                    '          .,                                              l i

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f  ! A gallon can of Edison Cleaner was produced with the label indicating the material to be trichlorethylene. I applied some of this material to the cover of one of the cells out

                         .of service.                                        When allowed to dry,.an almost identical mottling or etching pattern resulted as observed on most other cell covers.

It is postulated that the trichlorethylene was used to clean cell posts of No-ox-id "A" -grease during rework of intercell.

connections. Varying quantities of the cleaner came in contact with cell covers and in some cases ran over the edges of the covers coming.in contact with.the containers.

r In the case'of cells #3, 4 and 5, it appears.that a large

quantity of this cleaner was spilled between the cells saturating

the spacer material. Therefore, prolonged' exposure'of unevaporated cleaner to the mid j ar wall caused severe etching.

A sample of the' cleaner was obtain'ed and I brought-itLto Langhorne Lfor testing. .The GNB. Accelerated Stress Cracking Test P-130 was conducted exposing'an SAN test slab to the Edison Cleaner. Results-were rapid and dramatic.with the testislab breaking at the fulcrum pointiin about 10 seconds. Almost instantaneous crazing was Lobserved with slab f ailure shortly -therea,f ter.. As a resultiof our< findings at Byron as well asi-in-house testing of.the Edison. Cleaner,;a,visitJto: Braidwood Nuclear-Station was made'on 3-23-84.; GNB was represented _by Ramesh Desai,-Miles Todd andimyself with Mark-Stohr-representing. Janes Power Systems..

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The"first battery examined wasitheL116-NCX-1500 S/N KHF-1797'New E '8/80~ . This battery previously had 20 cells with.crackedLjars-i (jar-cover juncture area); and which were re-j arred and re-covered

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by MarkiStohr at GNB's expense. All cel1Leovershoffcells not

repaired were 1 examined fand .the maj orityf exhibitede the : mottling or

_ etching; observed at Byron ' Station. - We also' looked at a;58-NCX-1200 S/N -KJE-9 7 3E New; 9 / 79 fin Room '111'. . 1This. battery'previously?had>3'cellslwith cracked; jars which also. , ,were-repaired by:Ma'rkEStohr at GNB's expense'. .Here again, examination of unrepaired cells revealed mottlingfand. etching'of . covers in the'same manner ~ found on other batteries.where cracked ciarsfresulted. In the.~ afternoon a. meeting 7was' held tordiscuss our-findings-at:

                         .both Byron and Braidwood~as'wel1-as the resultsJof the-Accelerated.

Stress CrackingLTest. 'In" addition,;'IJrepeated the test'in the meeting' room.using EdisoniCleaner and' SAN test;. slab. Again,

                        < crazing: appeared lalmost instantaneouslyf followedfby7 failure'of-

thestestEslabsin about-six seconds'following. application-ofLthe:

                         < Edison'Cleanern                                                                               ,

s.

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Conclusion:

The use of Edison Cleaner on the cells resulted in stress release and cracking of a quantity of containers at both Byron and Braid-wood and in-no way was the result of a design-and/or material deficiency. This was pointed out to the nine Commonwealth ~ Edison people attending the meeting. 'In addition, we referenced the warning in our Operating Instructions against the use of solvents or mineral spirits as crazing and cracking of plastic materials could result. 6 y.. A e

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