ML20083G834

Interim Deficiency Rept Re Welding on Containment Liner Dome Closure Weld Seam.Initially Reported on 831201. Investigation Proceeding.Final Rept Expected in Approx 90 Days

ML20083G834
Person / Time
Site:	Clinton
Issue date:	12/29/1983
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, 1605-L, U-10116, NUDOCS 8401060433
Download: ML20083G834 (3)

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A ILLINDIS POWER 00MPANY . jg3 y_393 g CLINTON POWER STATION. P.O. BOX 678. CLINTON. ILLINOIS 61727 December 29, 1983 Docket No. 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 Subj ect : Potential 10CFR50.55(e) Deficiency 55-83-10 Weld Deficiencies on Containment Liner Dome

Dear Mr. Keppler:

On December 1, 1983, Illinois Power notified Mr. F.

Jablonski, NRC Region III (ref: IP memorandum Y-18886 dated December 1, 1983) of a potentially reportable deficiency per 10CFR50.55(e) concerning welding deficiencies identified on the containment liner dome closure weld seam. Our investigation of this issue continues, and this letter represents an interim report in accordance with 10CFR50.55(e)(3).

Statement of Potentially Reportable Deficiency / Background During the removal of temporary attachments from the con-tainment liner dome, vendor welding deficiencies were observed by Baldwin Associates (BA) personnel on the containment liner dome closure weld seam (designated R2-R3), fabricated by Chicago Bridge & Iron Co. (CB&I). The deficiencies include areas of undercut, porosity, incorrect weld profile, arc strikes, and several small cracks. Also found were dimensional tolerance violations during base metal fit-up of the weld, and the presence of a foreign substance on the seam weld. An evaluation is being performed to determine the full extent and significance of these conditions on operaticnal safety of Clinton Power Station (CPS)

Investigation Results/ Corrective Action Illinois Power has prepared and implemented an investigation plan to identify and evaluate the extent and nature of weld deficiencies and other irregularities noted by Baldwin Associates personnel. The investigation is proceeding in the following manner:

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lir. Jaues G. Keppler Page 2 December 29, 1983

1. The presence of the foreign substance, found in one (1) isolated location of the weld, is being investigated to identify the material, and to determine the stage of construction when the material was deposited on the weld. Illinois Power has retained the services of a chemist from Southwest Research Institute to inspect the area and to obtain and analyze a sample of the material.

2. Those areas reported as dimensionally out of tolerance will be identified and evaluated. It is not expected that the identified deviations will influence the functioning of the liner, as exterior containment concrete has already been placed.

3. Upon resolution of action 1. above, an area twelve (12) inches on either side of the closure seam R2-R3, and any adjacent areas exhibiting suspect indications, will be cleaned, visually inspected, and examined by magnetic particle (MT) testing. Nonconformance Reports will be written on any adverse indications.

4. Upon the completion of investigative actions, the result will be compiled and reviewed. Any adverse conditions will be dispositioned by the CPS Architect-Engineer, Sargent & Lundy. The need for additional inspections will be evaluated and the significance on operational safety of identified deficiencies will be determined.

As CB&I containment liner fabrication and welding is complete, corrective action on this issue has focused on the identification, disposition, and correction of existing hardware deficiencies. Nonconformance reports (NCRs) 11816, 11817, 11824, and 11825 have been written to document and obtain resolution of the nonconforming conditions identified to date.

Safety Evaluation / Significance Investigation of this issue is proceeding at this time to determine the_ full extent and nature of the welding deficiencies.

Until further inspection data has been obtained and evaluated, a definitive statement as to the affects of the welding defi-ciencies on the safe operation of Clinton Power Station cannot be made. It is expected that approximately ninety (90) days will be necessary to further evaluate this issue and to provide a final report on the matter.

.r" Mr. James G. Keppler Page 3 December 29, 1983 We trust that this interim report provides sufficient background information to perform a general assessment of this potentially reportable deficiency, and adequately describes our overall approach to resolve the issue.

Sincerely yours,

. . Hall Vice President RDW/cch cc: NRC Resident Office Director-Office of I & E, USNRC, Washington, DC 20555 Illinois Department of Nuclear Safety INPO Records Center