ML20079S166
| ML20079S166 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 01/25/1984 |
| From: | Hall D ILLINOIS POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 1605-L, 55-83-07, 55-83-7, U-10122, NUDOCS 8402030229 | |
| Download: ML20079S166 (4) | |
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1605-L ILLIN0/8 POVER 00MPANY fyy y_19322 CLtNTON POWER STATION, P.O. BOX 678. CLINTON, ILLINOIS 61727 January 25, 1984 Docket No. 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Subject:
Reportable Deficiency 55-83-07 10CFR50.55(e)
Pipe Shop Welds by Southwest Fabricating
Dear Mr. Keppler:
On June 14, 1983, Illinois Power Company notified Mr. F.
Jablonski, NRC Region III (Ref:
IP memorandum Y-15971, 1605-L, dated June 14, 1983) of a potentially reportable deficiency concerning the adequacy of shop welds on pipe spools fabricated by Southwest Fabricating and Welding Company and supplied to Baldwin Associates for use at Clinton Power Station (CPS).
This initial notification was followed by two (2) interim reports (ref:
IP letter U-10074, D. P. Hall to J. G. Keppler dated July 25, 1983: and IP letter U-10103, D. P. Hall to J. G. Keppler dated October 27, 1983).
Our investigation has determined that this issue represents a reportable deficiency under the provisions of 10CFR50.55(e).
Our investigation of this issue continues, and this letter is submitted as an interim report in accordance with 10CFR50.55(e)(3).
Statement of Reportable Deficiency During a re-review of radiographic film, rej ectable indica-tions were found in shop welds produced by Southwest Fabricating and Welding Company (SWF).
The welds in question are ASME Code Class I and II found in safety-related piping systems as well as some ANSI B31.1 welds found in other CPS piping systems.
Some welds were found to include cracks, lack of fusion, and slag inclusions.
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Mr. Jcmes G. K:ppler Pago 2 January 25, 1984 Background / Investigation Results During examination of a field radiograph taken of a weld repair on a SWF shop weld repaired by Baldwin Associates at CPS, questionable indications were noted in the root area of the SWF shop. weld cyay from the repair.
The weld repair was necessary due to overgrinding of the shop wald while " flat topping" in preparation for in-service inspection baseline examination.
The questionable indications were also noted in a re-review of SWF shop radiographic films of this weld.
Further investigation of shop radiographic film identified additional shop welds with questionable indications.
These SWF shop films were originally evaluated at receipt by a Baldwin Associates Quality Control inspector who is no longer available for consultation.
Baldwin Associates performed a re-review of a sample of radiographic film originally interpreted by this inspector.
Sixty-eight (68) welds were selected at random for review.
Fourteen of these welds were found to contain questionable indications.
The films of five (5) additional welds showed surface conditions that possibly could mask defects.
As a result of these findings, Southwest Fabricating and Welding reported June 24, 1983 to the Nuclear Regulatory Commission (Region IV),
under the rules of 10CFR21, of an apparent failure to comply with the requirements of ASME Section III, Paragraph NC-4424 for several of the questionable welds.
The welds documented in the report included four (4) pip ~.ng subassemblies with 45* lateral branch connections with reinforcing nads installed after radiography.
Due to the presence of these reinforcing pads, it is currently not possible to determine if indications on the film are surface indications.
An Investigation Plan was developed by Illinois Power that detailed the actions necessary to achieve satisfactory evaluation of the nineteen questionable welds.
This plan called for a re-radiograph of the nineteen (19) welds in the as-found condition after a visual inspection.
The radiography technique duplicated the original SWF technique as closely as possible.
Those welds having an irregular surface were then ground smooth and re-radiographed a second time.
A joint review of the radiographic film was then performed by SWF, Baldwin Associates, and an independent Designated Reviewer representing Illinois Power.
This review found that three (3) welds required an engineering evaluation and disposition of the indications found, one (1) weld remains indeterminate due to difficulty in interpreting the film and one (1) weld is considered acceptable, however, film density does not meet Code requirements.
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Mr. Jam:s G. K ppler Pcga 3 January 25, 1984 Corrective Action As large bore piping fabrication is essentially complete for Clinton Power Station, Illinois Power's efforts have focused on identifying the scope of this issue and on the correction of any identified weld deficiencies.
The following actions are presently being taken by Illinois Power:
1.
A revision to the Illinois Power investigation plan was prepared to include additional re-reviews of all Southwest Fabricating radiographs for film and weld quality on piping supplied to Baldwin Associates for use at Clinton Power Station.
This review includes radiographs of ASME Code Class I and II and ANSI B31.1 wel ds.
This review is being performed by a qualified Baldwin Associates reviewer and monitored by Illinois Power's Designated Reviewer.
To date, radiographs of approximately 2,400 of a total population of 3,100 welds have been re-reviewed.
Completion of this review is scheduled for March 31, 1984.
2.
Defects identified by the re-review are being documented on Nonconformance Reports (NCRs).
Eighty-three (83) NCRs have been written to date to document weld structural problems.
These welds will be repaired and re-radiographed to ensure Code acceptability.
An additional twelve (12) NCRs have been written to document software problems, such as radiographic film quality problems, weld identification problems, etc.
These conditions will be dispositioned and may require a re-radiograph of the affected weld.
3.
Illinois Power management has issued a hold on construction work on Southwest Fabricating pipe spools and welds until investigation of the shop welds has been performed.
Exceptions to this hold are allowed only on a case-by-case basis.
Safety Implications / Significance Re-reviews of previously accepted Southwest Fabricating shop welds identified eighty-three welds that do not meet ASME Code weld acceptance criteria.
In lieu of performing an extensive engineering evaluation of the specific weld defects identified, Illincis Power has postulated that the conditions identified could lead to weld failure in safety-related piping systems.
Such failure could prevent the systems from performing their intended safety function.
On this basis, this issue is considered significant, and therefore reportable under the provisions of 10CFR50.55(e).
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Mr. Jcmes G.'Keppler Pagn 4 January 25, 1984 a-It is anticipated that approximately ninety (90) days will be required to complete our investigation and provide a final report on the issue.
We trust that this interim letter provides sufficient'information to perform a general assessment of this deficiency and adequately describes our overall approach to resolve the problem.
Sincerely yours, D. P. Hall Vice President RDW/ lag cc:
!!RC Resident Office Director, Office of I&E, USNRC, Washington, D.C.
20555 Illinois Office of Nuclear Safety INPO Records Center 9