ML20151E868

Forwards Response to NRC Bulletin 88-001 Re Defects in Westinghouse Circuit Breakers in Class 1E Svc.All Required long-term & short-term Insps Completed

ML20151E868
Person / Time
Site:	Callaway
Issue date:	04/11/1988
From:	Schnell D UNION ELECTRIC CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
IEB-88-001, IEB-88-1, TAC-65955, TAC-65956, ULNRC-1752, NUDOCS 8804150412
Download: ML20151E868 (11)

Text

. _ _ _ _.

a 1901 Gratet Street, St. Louis Donald F. Schnell Vee Presdent April 11, 1988 U.S.

Nuclear Regulatory Commission ATTN:

Document Control Desk Washington, D.C.

20555-ULNRC-1752 Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT DEFECTS IN WESTINGHOUSE CIRCUIT BREAKERS _(TACS 6_5955f65956)

Reference:

NRC Bulletin Number 88-01, dated February 5, 1988 NRC Bulletin 88-01 required licensees using Westinghouse series DS circuit breakers in Class lE service to perform and document inspection of the welds on the pole shafts and inspection of the alignment in the breaker closing mechanism.

All of the required long term and short term inspections have been completed and the results are documented in the r.htachments to this letter.

If you have any questions concerning this information, please contact me.

Very truly yours, s

Donald F.

Schnell WEK/pkm Attachments gg\\\\

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Mah>g Aadress: P.O. Box 149. St Louis. MO 63166

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STATE OF MISSOURI )

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Donald F. Schnell, of lawful age, being first duly sworn upon oath says that he is Vice Presidenc-Nuclear and an officer of Union Electric Company; that he han read the foregoing document and knows the content thereof; that he has executed the same for and on behalf of said company with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.

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By D3ha

,.c ne Vice President Nuclear SUBSCRIBED and sworn to before me this

//b day of

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A u s Ana BARBARA J. PFAFy n e

i hatARY FUBdC, $1 ATE C; Mts$0VRt gy gcW4S10N EXPtRES AfRil Ik UI

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ST Louts COUNTY i

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4 cc Gerald Charnof f, Esq.

Shaw, Pittman, Potts & Trowbridge 2300 N.

Street, N.W.

Washington, D.C.

20037 Dr. J. O. Cermak CFA, Inc.

4 Professional Drive (Suite 110)

Gaithersburg, MD 20879 R.

C.

Knop Chief, Reactor Project Branch 1 U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137 Bruce Little Callaway Resident Office U.S. Nuclear Regulatory Commission RR$1 Steedman, Missouri 65077 Tom Alexion (2)

Office of Nuclear Reactor Regulation U.S.

Nuclear Regulatory Commission Mail Stop 316 7920 Norfolk Avenue Bethesda, MD 20014 Manager, Electric Department Missouri Public Service Commission P.O.

Box 360 Jefferson City, MO 65102

Attachmsnt 1 ULNRC-1752 NRC Bulletin 88-01 I_nspectlon_ o,f West _inghouse_ Circuit Breakers NRC Bulletin 88-01 required the inspection of Westinghouse series DS circuit breakers used in Class lE service.

Inspection of the welds on the pole shafts and of the alignment in the breaker closing mechanism were to be completed and transmitted to the NRC witin 1) 30 days of completion of the short-term inspections and 2) 30 days of completion of the long-term inspections.

The short-term and long-term inspections have been completed at the Callaway Plant and the results are documented herein.

There are eight (8) Westinghouse DS-416 reactor trip breakers at the Callaway Plant; 2 main trip breakers, 2 bypass trip breakers, and 4 spares.

These breakers were disassembled and inspected to the requirements described in bulletin 88-01.

Additionally, four replacement shafts were inspected.

The results of these inspections are documented in Attachment 2 and summarized below:

1)

All breakers required or will require corrective action due to the pole shaf t welds not meeting one or more of the weld acceptance cr iteria.

All breakers currently in use meet the 6.1.2 criteria, as a minimum.

(Shafts meeting G.l.2 criteria are acceptable for up to 4000 cycles with inspections after every 200 cycles of operation.)

2) 2 replacecent shafts failed acceptance criteria for replacements and were rejected.

3)

All of the breakers were inspected for mechanical misalignment, with no failures noted.

Those breakers in use which have a shaf t that failed criteria 6.1.1 but passed criteria 6.1.2 will be replaced at the next available opportunity.

Union Electric concurs with the position on weld porosity acceptance criteria as discussed in Westinghouse's letter to the NRC dated March 1,1988 ( NS-NRC-88-3314).

This letter noted that weld porosity was considered to be a secondary ef fect to weld f atigue strength and that a qualified weld inspector would easily be able to identify and evaluate a weld with high porosity.

As such, the NRC criteria is too stringent and the Westinghouse criteria should be considered as an acceptable inspection method.

Page 1 of 2

The staf f time to per form the requested inspections, corrective actions, and associated operability testing is as follows:

!!aintenance Electricians 224 manhours Planning & Scheduling 60 manhours Level III Welding Incpector 50 manhours Maintenance Engineering 80 manhours Welding Engineering and other Management Personnel 15 manhours Page 2 of 2

C INSPECTION RESULTS b

POLE SHAFT ASSEMBLY Weld 1 Weld 2 Weld 3 Weld 4 Weld 6 Weld 7 l

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r WELD INSPECTION ALIGNMENT 1? ELD NUMBER SIZE LENGTH FUSION CRACKS POROSITY OF REMARKS BREAKER RTB "BYA", S7N 02YN051B-3, Work Request W106916 Accepted per 6.1.2 Wald 1 3 /16-k 1k" Accept Accept Accept Accept Meets criteria 6.1.1 Wald 2 NYI33 1k" Accept Accept Accept Accept Failed criteria 6.1.1, met 6.1.2 Wald 3 3/16" 1 1/16" Accept Accept Accept Accept Meets criteria 6.1.1 f

Wald 4 3f16 1 5/16" Accept Accept Accept Accept Meets criteria 7.1 Wild 5 N/A N/A Accept N/A N/A Accept Meets criteria 7.1 exception Wald 6 7/32 1 3/16" Accept Accept Accept Accept Meets criteria 6.1.1 i

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Weld 7 5/32 1 1/16" Accept Accept Accept Accept Meets criteria 7.1 r

Shaft rejected and was replaced with shaft S/N 880-132-7 RTB "B" S/N 02YN051B-4, Work Request W110204 (NMR 88100066)

~ Wald 1 1/8" ik Accept Accept Accept Accept Meets criteria 7.1 Umid 2 1/8" Ik Accept Accept Accept Accept Failed criteria 6.1.1, met 6.1.2 1

Vald 3 1/8" 1 1/8 Accept Accept Accept Accept Failed criteria 6.1.1, met 6.1.2 Wald 4 1/8" 1 5/16 Accept Accept Accept Accept Meets criteria 7.1 Wild 5 N/A N/A Accept N/A N/A Accept Meets criteria 7.1 extension Wild 6 (1/8" 1 1/8 Accept Accept Accept Accept Failed criteria 6.1.1 and 6.1.2 i

W21d 7 1/8" 1 3/16 Accept Accept Accept Accept Meets criteria 7.1 l

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i Page 1 of 6 ATTACHMENT 2 t

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INSPECTION RESULTS POLE SHAFT ASSEMBLY Weld 1 Weld 2 Weld 3 Weld 4 Weld 6 Weld 7

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r WELD INSPECTION ALIGNMENT WELD NUMBER SIZE LENGTH FtJSION CRACKS POROSITY OF REMARKS BREAKER RTB "BYB" S/N 02YN051B-2, Work Request W110207 Accepted per 6.1.2 Wald 1 5/32" 15/16" Accept Acceot Accept Accent Meets criteria 7.1 W2ld 2 $33 1 5/32 Acceot Accept Accept Accept Failed criteria 6.1.1, met 6.1.2 Wald 3 5/32" 1 1/16" Accept Accept Accept Accept Failed criteria 6.1.1, met 6.1.2 Wald 4 1/8" 1 1/16" Accept Accept Accept Accept Meets criteria 7.1 Wald 5 N/A N/A Accept N/A N/A Accept Meets criteria 7.1 exception Weld 6

"$/I6 15/16" Accept Accept Accept Accept Failed criteria 6.1.1, met 6.1.2 _

Wald 7 ldt32 1 1/16" Accept Accept Accept Accept Meets criteria 7.1 Spare Breaker S/N 02YN0583-2 Work Request W431904 Accepted per 6.1.2 1/8 -

Wald 1 3/16" 1"

Accent AcceSt Accent Accent Meets criteria Wald 2 h)16" 1"

Accept Accept Accept Accept Failed criteria 6.1.1 meets 6.1.2 Wald 3 Nf16" 15/16" Accept Accept Accept Accept Failed criteria 6.1.1. meets 6.1.2 W31d 4 5/32" 1"

Accept Accept.

Accept Accept Meets criteria 7.1 W21d 5 N/A N/A Accept N/A N/A Accept Meets criteria 7.1 exception Vald 6 5{p$6' 1"

Accept Accept Accent Accept Failed criteria 6.1.1, meets 6.1.2 lid -

W2ld 7 5/32 15/16 Accent Accent Accent Accept Meets criteria 7.1 Page 2 of 6 ATTACHMENT 2

INSPECTION RESULTS POLE SHAFT ASSEMBLY Weld 1 Weld 2 Weld 3 Weld 4 Weld 6 Weld 7

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WELD INSPECTION ALIGNMENT UELD NL'MBER SIZE LENGTH FUSION CRACKS POROSITY OF REMARKS BREAKER Spare Breaker S/N 02YN058B-1 Work Request W106919 (NMR 88100067) Shaft Reiected Not inspected due to failure of #6 Wald 1 Not inspected due to f ailure of 86 Wald 2 Not inspected due to f ailure of 86 Wald 3 Noeinseect,a N ~ s u i n.,

4, #6 Wild 4 Not inseected due en fuluvo nr u U21d 5 Failed criteria 6.1.1 and 6.1.2 Wald 6 (1/8" Not inspected due to failure of #6 Wald 7 Spare Breaker S/N 02N058B-3 Accepted per 6.1.2 Wald 1 1/8" 7/8" Accept Accept Accept Accept Meets criteria 7.1 Failed criteria 6.1.1, met 6.1.2 Weld 2 1/8" 1"

Accept Accept Accept Accept Celd 3 3/16" 1\\"

Accept Accept Accept Accept Meets criteria 6.1.1 Wald 4 3/16" 1"

Accept Accept Accept Accept Meets criteria 7.1 Meets criteria 7.1 exception Weld 5 N/A N/A Accept N/A N/A Accept Failed criteria 6.1.1, met 6.1.2 W21d 6 1/8" l"

Accept Accept Accept Accept U21d 7 1/8" 7/8" Accept Accept Accept Accept Meets criteria 7.1 o

Page 3 of 6 ATTACHMENT 2

INSPECTION RESULTS POLE SHAFT ASSEMBLY Weld 1 Weld 2 Weld 3 Weld 4 Weld 6 Weld 7

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WELD INSPECTION ALIGNMENT WELD NUMBER SIZE LENGTH FUSION CRACKS POROSITY OF REMARKS BREAKER Shaft Rejected and Was Replaced RTB "A" S7N 02YN0513-1. Work Request W110205 (NMR 88I00054) With Shaf t From SA'02YN058B-2 Not inspected due to failure of #7 Uald 1 Not inspected due to failure of #7 Wald 2 Not inspected due to failure of #7 Wild 3 Not inspected due to failure of #7 Wald 4 Not inspected due to failure of #7 Wald 5 Not inspected due to failure of #7 Wald 6 Failed 7.1 Wald 7 41/8 reject Replacement 32' Spare Breaker S/N 02YN058B-4, Work Request W110206 (NMR 88I00072)

Shaft Rejected,

~ Wald 1 1/8" 7/8 Accept Accept Accept Accept Me.:ts criteria 7.1 Wald 2

< 1/8" 15/16" Accept Accept Accept Accept Failed criteria 6.1.1 and 6.1.2 Wald 3

( 1/8" 3/4" Accept Accept Accept Accept Failed criteria 6.1.1 and 6.1.2 L/6 -

U21d 4 3/16" 3/4" Accept Accent Accept Accept Failed criteris 6.1.1.snd 6.1.2 Wald 5 N/A N/A Accept N/A N/A Accept Meets criteria 7 i exception Weld 6 1/8" 11/16" Accept Accept Accept Accept Failed criteria 6.1.1 and 6.1.2 L/o -

Cold W21d 7 3/10 3/8" St3rt &

Accent Accent Accent Filled criteria 7.1 stop Page 4 of 6 ATTACHMENT 2

INSPECTION RESULTS POLE SHAFT ASSEMBLY 4

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r WELD INSPECTION ALIGNMENT WELD N1'MBER SIZE LENGTH F1)SION CRACKS POROSITY OF REMARKS BREAKER 1

Replacement Shaft S/N 880-132-6 Shaft Accepted - Meets Criteria Weld 1 Accept Accept Accept Accept Accept N/A Meets 7.1 Weld 2 Accept Accept Accept A: cept Accept N/A Meets 6.1.1 Wald 3 Accept Accept Accept Accept Accept N/A Meets 6.1.1 l

W21d 4 Accept Accept Accept Accept Accept N/A Meets 7.1 Wild 5 N/A N/A Accept N/A N/A N/A Meets 7.1 exception Wald 6 Accept Accept Accept Accept Accept N/A Meets 6.1.1 W21d 7 Accept Accept Accept Accept Accept N/A Meets 7.1 Replacement Shaft S/N 880-132-7, Shaft Accepted - Meets Criteria Vald 1 Accept l Accept Accept Accept Accept N/A Meets 7.1 Wild 2 Accept Accept Accept Accept Accept N/A Meets 6.1.1 U21d 3 Accept Accept Accept Accept Accept N/A Meets 6.1.1 Wald 4 Accept Accept Accept Accept Accept N/A Meets 7.1 W21d 5 N/A N/A Accept N/A N/A N/A Meets 7.1 exception W.1d 6 Accept Accept Accept Accept Accept N/A Meets 6.1.1 aid 7 Accept Accept Accept Accept Accept N/A Meets 7.1 Page 5 of 6 ATTACHMENT 2

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INSPECTION RESULTS i

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WELD INSPECTION ALIGhMENT 1.rE1.D NUMBER SIZE LENGTH FUSION CRACKS POROSITY OF REMARKS 4

BREAKER Replacement Shaft S/N 880-132-1, hKR 88100059 Shaft Rejected and Returned to Westinghouse i

Wald 1 1/8" 1 5/16" Accept Accept Accept N/A Meets criteria 7.1 t7 eld 2 1/8" 1 3/8" Accept Accept Accept N/A Failed criteria 6.1.1, met 6.1.2 l

Unid 3 1/8" ik" Efkht Accept Accept N/A kk*kt N h d" see 4,T Y 8

W2ld 4 1/8" 1 3/16" Accept Accept Accept N/A Meets criteria 7.1 j

Wald 5 N/A N/A Accept N/A N/A N/A Meets criteria 7.1 exception 17 eld 6 1/8" 1 3/16" Accept Accept Accept N/A Failed criteria 6.1.1, met 6.1.2 l

Vald 7 3/16 1 5/16" Accept Accept Accept i N/A Meets criteria 7.1 J

Replacement Shaft S/N 880-132-2, NMR 88100059, Shaft Rejected and Returned to Westinghouse

~ Unid 1 1/8" th" Accept Ae:ept Accept N/A Meets criteria 7.1 l

Wald 2 1/8" 1 7/16" Accept Accept Accept N/A Failed criteria 6.1.1, met 6.1.2

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U21d 3 1/8" 1 9/16" Accept Accept Accept N/A Failed criteria 6.1.1, met 6.1.2 I

Wald 4 1/8" 1 3/8" Accept Accept Accept N/A Meets criteria 7.1 Wald 5 N/A N/A Accept N/A N/A N/A Meets criteria 7.1 exception l

I Wald 6 1/8" ik" Accept Accept Accept N/A Failed cri:eria 6.1.1, met 6.1.2 co start and stop l

Wald 7 3/16 1 3/8" Acceptr Accept Accept N/A

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Page 6 of 6 ATTACHMENT 2 l

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