05000457/LER-1990-005

LER 90-005-00:on 900426,discovered That Diesel Generator 2A Starting Air Distribution Sys Tubing Crisscrossed to Cylinders 6L & 9L.Caused by Preservice Mfg Deficiency. Custom-routed Airlines replaced.W/900524 Ltr

ML20055C643
Person / Time
Site:	Braidwood
Issue date:	05/24/1990
From:	Grzemski J, Querio R COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BW-90-0566, BW-90-566, LER-90-005-09, LER-90-5-9, NUDOCS 9005300163
Download: ML20055C643 (4)

LER-2090-005,

Event date:
Report date:
4572090005R00 - NRC Website

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3 Commonwealth Edison-- .

'- / V)- IValdwood Route #1, Box Nucleir Powtr St; tion .!

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h / ' Bracoville, Illinois 60407

\x j Telephone 815/458-2801:

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i May 24,1990 ,

BW/90-0566

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.t U. S. Nuclear Regulatory Commission Document Control Desk l Washington, D.C. 20555 ,

Dear Sir:

+

The enclosed Licensee Event Report from Braldwood Generating

- Station is being transmitted to you in accordance with the requirements of  ;

- 10CFR50.73(a)(2)(1)(B) which requires a 30-day written report. j This report is number 90-005-00; Docket No. 50-457.

i Very truly yours, ic .t j

L R. E Querlo l Station Manager Braidwood Nuclear Station i REQ /JDW/jfe '

-(7126z) l

Enclosure:

Licensee Event Report No. 90-005-00 l cc: NRC Region Ill Administrator NRC Resident inspector INPO Record Center CECO Distribution List p .

i 9005300.163 900324 PDR g2.b 6 ADOCK 05000457 p' PDC g .d4 .

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LICENSEE EVENT REPORT (LER) 7 Facility Name (1) ., Docket Number (2) fastl31

.ItteldEonL2 fjLojaLQlAJl_.L1_of! 0 ! 3 Title (4) Diesel Generator Crisscrossed Starting Air Distribution System Tubing due to Pre-service Manufacturing Deficiency c _IrtoLQittJ5) LER_NumhtI_(f) RtP2tLQaitJ1} Othatltillilles InvohtL18)

Month Day Year _ Year /// Sequential // Revision Month Day Year .ltiility Ngings._ aptit13gmitIls) ff

//j/ Number

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// Number.

Nont O!510]Ojj l l al 4 21 6 RLL ala_ -o_Lo I 5 J J _ L _0_L L all 3 Lo _0J3!AlL01J__L OPERATING ifhetLgat_gr more of the followingLill)  !

20.402(b) __ 20.405(c) _. 50.73(a)(2)(lv) 73.71(b) )

-_ POWER 20.405(a)(1)(1) _ 50.36(c)(1) 50.73(a)(2)(v) ._ 73.71(c) l LEVEL _ 20.405(a)(1)(ti) __ 50.36(c)(2) 50.73(a)(2)(vii) _ Other (Specif y  !

(10) ,_Q_ Q ! 0_ ._. 20.405(a)(1)(iii) l 50.73(a)(2)(1) __ 50.73(a)(2)(viii)(A) in Abstract

/ j/ j j/ j j j j /j j j j j j j/ j j j/ j j j/j j j /j j/ //// ///// 20.405(a)(1)(iv)

// /// // / _._ 50.73(a)(2)(li)- _._ 50.73(a)(2)(viii)(B) below and in i

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g g g g g g jff _._ 20.405(a)(1)(v) __ 50.73(a)(2)(ill) ._ 50.73(a)(2)(x) Text)

LICENSEE CONTACT FOR THIS_LER (12)

Name TELEPHONE NUti)ER AREA CODE

.11m Grrtinski . Tech _S14f.f F.Dgr. Ext. 2402 _8_ l 1_ IJ_ lilllL-JallLold C0tiPLETE bHE L1HL[0R_EACH CQti?ONEN FAILURLDESCRIDIQ_1R.Iti1LREEORT (131 )

CAUSE SYSTEH COMPONENT MANUFAC- REPORTABtE CAUSE SYSTEM COMPONENT MANUFAC- REPORTABLE y

._JDRER _10JERQL JURER 10JERDL I I _LJ l !I I - _

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I LJ ! I I I i 1I I L_L.L. f iVffLEMENTAL REPORT EXPECTED (14) Expected tivnth I Day l Yes.t I Submission

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lyes (If vis. complete EXPECTED SUBMISSION DATE) X l _ NO l ll j_

ABSTRACT (Limit tc 1400 spaces, i.e, approximately fifteen single-space typewritten lines) (16) i On April 26, 1990 during the performance of scheduled maintenance on the 2A Diesel Generator (DG) a crisscross of the starting airlines for 2 cylinders was discovered while time checking each individual cylinder. These time checks had been added to the inspection as a corrective action from a previous event involving the IB DG. In that event the starting airlines had been crisscrossed at couplings following exhaust manifold replacement. The error on the 2A DG occurred during the custom routing of the tubing into th) starting air distributor. This routing is performed during the original manufacturing process. With the  !

existing custom tubing it was not possible to obtain a simple airline swap. A review of the starting -l histories for the 2A DG Indicated that the crisscross of the starting airlines did not significantly ef fect i thy performance of the 2A DG, The 2A DG had experienced only one " slow start" f ailure and had experienced 43 {

successful starts since the completion of pre-operational testing. The cause of the event was pre-service ranufacturing deficiency. The defective custom routed airlines were replaced. The inspection that identifled this deficiency was part of the corrective action for a previous event. This inspection has been l I

completed for 3 of the 4 DGs and will be completed for the remaining DG, This event has been submitted to engineering for 10 CFR part 21 consideration.

3017a(052390)/2

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'i1EENSEE EVENT RENILT (LER) . TEXT EONTINUATION Form Rev 2.0

, FACILITY NAME (1)

• DOCKET NUMBER (2) I J.IR hut 9EIL[$1 PAgg._{3)'

. Year fj// Sequential

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///

fff Revision HZJ mber... UL Number y _g.cgidsgod 2 0 1 5 1 0 1 0 1 0 l'41 51 7 910 - 01015 - 01 0 01 2 0F. 01 3

TEXT Energy Industry Identification System (E!!S) codes are identified in the text.as (XX)

' A.

. PLANT CONDITIONS PRIOR TO EVENT:

'Ualt:' Braldwood 2; Event Date: April 26, 1990; Event Time: .0900; Mode: ' 6 - Refueling; Rx Power: 0%;

RCS (AB) Temperature / Pressure: Ambient / Atmospheric

'B. DESCRIPTION Of EVENT:

There were no systems or components.troperable at the beginning of the event which contributed to the severity of th) event.

- At 0900 on April 26, 1990 during the performance of the scheduled 18 month maintenance on the 2A Diesel Generatorf I (DG). (EK) a crisscross of the starting. air distribution system tubing to cylinders 6L and 9L was discovered. The 1 discovery occurred while time checking each individual cylinder. Individual cylinder time checks were 'not "

normally performed for scheduled 18 month maintenance but had been added to this inspection as a' corrective action from a previous event involving the IB DG (reference LER 50-456/90-006). In,that event the starting airlines to 4 cylinders had been crisscrossed at couplings in a tubing trough following exhaust manifold replacement.

Af ter the crisscross of the starting airlines on the 2A DG was discovered the tubing couplings.were inspected a'nd ]

found to'be correctly assembled per the vendor stamped numbers. The error occurred during the custom routing of. 1 the tubing into the starting air distributor._ The custom routing is performed during the original manufacturing L J pr cess at.the factory. With the existing custom tubing it was not possible to obtain a simple airline swap. d L A review-of 'the starting histories for the 2A DG was conducted. Based on the results of that review it has been-concluded that the crisscross of the 6L:and 9L starting airlines did not significantly effect the performance of , '

th) 2A DG. The 2A DG had experier.ced only one " slow start" failure. This was a start time of 10.7 seconds as 1

.rscorded by a. stopwatch. This was in excess of tbo 10 seconds required by Technical Specifications. The 2A DG

,his experienced approximately 43 scccessful starts since the completion of pre-operational testing.

This event is being reported pursuant to 10CFR50.73(a)(2)(1)(B)-any operation or condition prohibited by the s plants Technical Specifications. ]

i C. .CAUSE OF EVENT: q

-The root cause of this event was a pre-service manufacturing deficiency.

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. D. SAFETY ANALYSIS:

{

l This' event.had no effect on the safety of the plant or the public. Based on .trformance histories, the crisscross  !

-of the 2 starting air lines did not significantly ef fect the performance of the 2A DG and it is reasonable to assume that-it would have performed as designed had an actual initiation signal occurred.

-3017)(052290)/3 1

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, . LIIENSILIYENLRLi'OfLLiLER) TEXT CQNTINUATION Fot3L.Erv 2.0 FACILITY-NAME,(1)

DOCKET NUMBER (2) _ LER NUMBL!L(j) pa.ge (3)

- Year /// Sequential /jj fjj

// Revision f

LU- 826tt lH Humktt

_prajdgend 2 0 1 5 1 0 [1]_Q l 41 51 7 910 - . O Lo.l.1 - 01 0 03 1 at 01.3 TEXT; Energy. Industry Identification System (Ells) codes are identified in the text as (XX)  ;

D. SAFElf ANALYSI$: (Continued)

Undir. the worst case conditions -of a DG f ailure occurring af ter a valid initiating signal following a Safety

' Injection there would still be no ef fect. The redundancy of the safety system design provides for full safe shutdown and accident mitigation capability f rom A single ESF bus. The diversity of the electrical . p distribution system provides for powering an ESF bus from its $ystem Auxiliary Transformer, its own Diesel . i"

' Gen:rator, or its corresponoing opposite Unit ESF bus which is capable of being powered from its Diesel

Generator or System Auxiliary Transformer. This is enveloped in section 8 of the Updated final Safety- l

- An31ysis Report.

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'E.- CORRECTIVE ACTIONS: ,

.The defecti ve custom rou et d airlines were replaced.

The' inspection that identified this deficiency was part of the corrective action for LER 50-456/90-006. The inspection of 1 A, IB, and 2A DG's is complete. Action item 456-200-90-01901 continues to track this item to

~

- completion for the inspection of the 2B DG.

/ This item has been submitted to Nuclear Engineering Department for 10CFR part 21 consideration. This will be

"' tr cked to completion by action item 457-200-90 01301. .

4

.F. PREVIOUS OCCURRENCES:

Th;re was a previous occurrence of crisscrossed DG starting airlines.

LER Title 50-456/90iOO6 Diesel Generator Slow Start From Crisscrossed Starting Airlines due to progrannatic Deficiency

- The; inspection that identified this deficiency was the result of corrective actions taken for that event.

G. COMPONENT FAILURE DATA:

This event was not the result of. component f ailure, nor did any components f ail as a result of this event.

301h(if.;2% /4 s