ML20117N396

Interim Potential Deficiency Rept 55-85-04 Re Deficient Welds on Butterfly Dampers Supplied by Pacific Air Products Co.Initially Reported on 850404.Investigation Plan Prepared & Implemented to Determine Extent of Deficiency

ML20117N396
Person / Time
Site:	Clinton
Issue date:	05/07/1985
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
55-85-04, 55-85-4, U-10274, NUDOCS 8505170509
Download: ML20117N396 (3)

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ILLINDIS POWER 00MPANY 1A.120 CLINTON E T T ON. P.O. BOX 678. CLINTON. ILLINOIS 61727 Docket No. 50-461 May 7, 1985 Mr.-James G. Keppler Regional Administrator Region III .

, U.'S. Nuclear Regulatory Commission 799' Roosevelt Road Glen Ellyn, Illinois 60137

SUBJECT:

Potential 10CFR50.55(e) Deficiency 55-85-04:

Deficient Welds on Butterfly Dampers Supplied By Pacific Air Products Company

Dear Mr. Keppler:

On April 4, 1985, Illinois Power Company verbally notified Mr. F. Jablonski, US NRC Region III (Ref. IP memorandum Y-26229

, dated April 4, 1985) of a potentially reportable deficiency concerning the indeterminate' quality of butterfly dampers installed at the Clinton Power Station (CPS) and supplied by Pacific Air Products Company. Our investigation of this issue is continuing and this letter represents an interim report in accordance with the requirements of 10CFR50.55(e). Attachment A provides the details of our investigation.

We trust that this interim report provides you sufficient background information to perform a general assessment of this

. potentially reportable deficiency and adequately describes our overall approach to resolve this issue.

Sincerely yours, D. P'. Hall Vice President ZZ/lr (NRC2)

Attachment cc: NRC Resident Office Director, Office of I&E, US NRC, Washington, DC 20555 Illinois Department of Nuclear Safety INPO Records Center i gea7 I

MAY 101985 g g 8505170509 850507 gon Apocn05M7pgi L

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ATTACHMENT A Illinois Power Company Clinton Power Station Docket No. 50-461 Potential 10CFR50.55(e) Deficiency 55-85-04 Deficient Welds on Butterfly Dampers Supplied By Pacific Air Product Company Interim Report Statement of Potentially Reportable Deficiency / Background Baldwin Associates (BA) Resident Engineering has identified a deficiency with the welds on butterfly dampers (Ref.

Nonconformance Reports (NCRs) 28523 and 28526). The condition involves butterfly dampers installed in the Standby Gas Treatment (VG) and Drywell Purge Air (VQ) ventilation systems. The fillet

. weld attaching the damper sleeve to the damper flange failed such-that the flange pulled away from the damper sleeve during bolting to the mating pipe flange. Butterfly damper IVG17YB was returned to the Pacific Air Product Co. (PAPCO) on March 26, 1985, for repair or replacement (Ref. NCR 28526). Upon receipt, PAPCO conducted an evaluation and has determined that.the cause of the weld failure was lack of adequate fusion on the fillet weld between the flange and the sleeve of the damper (Ref. PAPCO letter from L. R. Hess to R. Riedy (BA Subcontracts), dated April 1, 1985). The quality and adequacy of these dampers to perform their design function is indeterminate.

Investigation Results Illinois Power has prepared and implemented an investigation plan to determine the extent of this deficiency at Clinton Power Station (CPS). The investigation plan includes the following actions:

1. A review to identify the number of pipe mounted dampers utilized in safety-related systems was performed. Of 27 units that are to be installed at CPS, 24 are utilized in safety-related applications.

2. An evaluation of the formal " Investigation Report" supplied by PAPCO (dated April 9, 1985), on the causes of the weld failure will be performed.

3. A review to identify other items / materials received from PAPCO will be perform 1d, as determined from item 2 above.

4. A determination of the necessity for PAPCO to review the other welds on the pipe mounted butterfly dampers, will be made.

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ATTACHMENT A (continued)

5. The return of all pipe mounted. butterfly dampers to PAPCO for repair or replacement.

. Complete. corrective action needed to correct the specific problems and to eliminate-the root cause(s) to preclude recurrence.will-be addressed after=further background information is evaluated.

Safety Implications / Significance Illinois Power's investigation of this potentially reportable deficiency is continuing. The, safety implications and significance will be assessed after further background information has been evaluated. It is anticipated that approximately sixty

-(60) days will be required to complete our investigation, determine reportability and to file a final report on the issue. ,

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