ML19329E802

Interim Deficiency Rept Re Cracked Weld Between Stiffener & Welding Ring of Personnel Lock.Caused by Improper Joint fit-up.Approved Repair Procedure w/post-weld Heat Approach May Be Impractical.Alternate Design Discussed

ML19329E802
Person / Time
Site:	Midland
Issue date:	04/19/1978
From:	Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML19329E794	List: ML19329E802 ML19329E805
References
HOWE-58-78, NUDOCS 8006170955
Download: ML19329E802 (4)

Text

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8 Stephen H. Howell y~

Voce President ,

' General Offices: 212 West Michigan Avenue, Jackson. MicNgan 49201 April 19, 1978 Howe-58-78 Mr J. G. Keppler, Regional Director Office of Inspection and Enforcement l

• US Nuclear Regulatory Commission

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Region IIX 799 Roosavelt Road Glen Ellyn, IL 60137 l MIDLAND NUCLEAR PLANT ,

i UNIT NO. 1, DOCKET NO. 50-329 "

I UNIT NO. 2,' DOCKET NO. 50-330 r .

i CONTAIN4ENT BUILDING PERSONNEL'~ AIR. LOCKS O In accordance with the requirements of:10.CFR 50 55(e)pthis-letter-constitutes an interim report of the status of the containment building personnel locks

, which have nine defective vendor velds (four in the Unit 1 lock and five in the Unit 2 lock) used to attach stiffeners to the personnel lock structure.

' The. attachment.to this letter supplements.the information in.the' previous.

i ini,erim report.L.

Another. report,;either_ interim or final,. vill be sent on or before-May 26;--

1978. *

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Attachment:

Interim Reporti f2 for NCAR-20, dated March 31, 1978, " Cracked ,

l WeM Between Stiffener and Welding Ring of Personnel Lock" CC: DrErnstVolgenau,USNRC(15)

Director of Office of Management

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Information and Program Control, USNRC (1)  !

C AM 211978 I

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• ECi;i E1, ASSOCI ATif iRO:7.M 18- R ?.:iOCI.ATION e

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SUBJECT:

HCAR #20 (Issued February 1, 1978) ,

Cracked weld between stif fener and welding ring pf personnel lock INTERIM REPORT #2 ,

~

DATE: March 31, 1978 PROJECT: Consumers Power Company Midland Plant Units 162 .

Bechtel' Job 7220 , ,

Introduction .

This report is submitted to advise of the interim status and course of .'

action required pursuant..to.MCAR #20 and_NCR.1185. An interim repo.rt was prepared 6n- thi's~ subj'ect on February 17;31978?*" .

The' final report.was scheduled to b'e completed by.}iarch.31; 19787..but.: ,

- the problem-of po.st-weld . heat treatment, requirements =in: ther.repairan-procedure proposed:by. W.J. Woolicy and Co.has not yet_been.. resolved._. .

The final report is rescheduled for thy 1,-1978, for resolution of this -

f"k problem. ,

Deficiency The deficiency. was.'diccussed in..the' previous . report.-

~ .

. Safety:Implicationses As stated in' BLC-5623, W.J.. Woolley- & Co,- the designer of the subj ect -

lockst.has advised-Bechtel;that;thenstructuralnintegrity of. the inner-

- ' bulkhead against imposed loading cannot te' guaranteed in its present state. Under normal reactor operation, both doors of-the personnel lock are c.loned. However, the door may be open for normal entry and exit to and from the containment or when the lock is being tested to verify that only one door in each lock can be operated at a time. Hence, for a -

limited time, the inner door may act as a primary pressure boundary. -

- However, the deficiency is not latent in nature and would have been '

- - detected during'the structural integrity test when the inner door was closed. .

Corrective Action It is assumed that the fillet welds failed because of improper joint ' -

fit-up." The excessive gap reduced the effective fillet weld leg which failed.when stressed upon field wc141ng. Pro Fab, the fabricator of the

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The matter is a y, . r.ubject locks, did not have a " fillet" welding procedure.

under investigation for proper resolution.

A repair procedure for the cracked fillet velds was received from .

W. J. Woolley Co. on March 24, 1978. It has been reviewed by Bechtel

' - and found acceptable. llouever, impicmentation of the post-weld heat treatment (PWilT) requirements may be impractical and an alternate design approach requiring no PWilT is being discussed with the W. J. Woolley Co.

If found acceptabic, W. J. Woolley Co. would incorporate the proposed modification into its design and repair procedure.

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- Submitted by: . [1 YB [6

- Approved by: ' ' *

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Concurrence by: " '

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(. .- Company c..a... ome..: m w . uicnia.a 4..ao.. s.em.oa. uicas.. .eaoi . A,.. co.. . , 2...o..o April 19, 1978 Hove-60-78 .

Mr J G Keppler, Regional Director Office of Inspection and Enforcement j

US Nuclear Regulatory Commission Region III 799 Roosevcit Road '

Glen Ellyn, IL 6013T i ___

y MIDLAND NUCLEAR PLANT - -

UNIT NO. 1, DOCKET NO. 50-329 UNIT NO. 2, DOCKET NO. 50-330 REACTOR BUILDING SPRAY PIPING SUPPORTS In accordance with the requirements of 10 CFR 50 55(e), this letter constitutes an interim report on the status of the reactor building spray piping supports which potentially exceed ASME Section II'. Code allowable stresses.

A description of the ' discrepancy, potencial safety implications, investigation and planned corrective actions are documented in the attachments to this letter.

Another report, either interim or final, vil be sent on or before June 16, 1978.

A t - s. A

Attachment:

1. Quality Assurance Program, Management Corrective Action Report, MCAR-1, Report 22.

2. Letter, P.A. Martinez to G.S.Keeley, BLC 5801,4 MCAR-22, Interim Report #1, with attached report. ,

CC: Dr Ernst Volgenau, USNBC (15) ,

• Director of Office of Management

' Information and Program Control, USNRC (1) . . . _ .

2,

.APR 211978

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