ML20136J057
| ML20136J057 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 08/31/1984 |
| From: | Swartz E COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20136J064 | List: |
| References | |
| 9130N, NUDOCS 8511250271 | |
| Download: ML20136J057 (5) | |
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Commonwealth Edison One First National Plarl, Chicago. Illinois u
Address Reply to, Post Office Box 767
- Chicago, lihnois 60690 August 31, 1984 Mr. James G. Keppler Regional Administrator U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, Il 60137
Subject:
Braidwood Station Units 1 and 2 Supplemental Response to Inspection Report No. 50-456/83-09; 50-457/83-09 NRC Docket Nos. 50-456 and 50-457 References (a):
L. O. De1 George letter to J. G. Keppler dated July 6, 1984 (b):
E. D. Swartz letter to J. G. Keppler dated July 23, 1984 (c):
J. G. Keppler letter to J. J. O'Connor dated May 7, 1984
Dear Mr. Keppler:
References (a) and (b) provided the Commonwealth Edison Company response to the Reference (c) Inspection Report Number 50-456/83-09; 50-457/83-09 concerning our Braidwood Station. The purpose of this letter is to provide a supplement to our Reference (a) response to Non-Compliance Items 2c, 3a and 3c.
For your convenience, this information is provided in the form of supplemental pa Reference (a) response.ges numbered 13a, 22a, 22b and 26a to our Ver uly purs,,
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Revision 2 dated August 31, 1984
- 13a -
Response to Item 2c (cont'd)
SLPPLEENTAL RESPONSE In order to provide additional assurance that piping bends meet the i
ovality requirements, a statistical sample of the small bare process piping bends will be performed by the Phillips, Getschow Company. A list will be developed for the safety related 2 inch and under process piping isometrics which have been "as-constructed" and which contain piping bends. From this list, a random sample will be selected and a documented QC inspection of the selected isometrics will be performed. This inspection will l
entail measuring the ovality of each piping bend, and also measuring the wall thickness of the pipe on the outer face of the bend. Acceptability of the piping bends will be based on the criteria set forth in the Phillips, Getschow Company Prccedure PGCP-ll and the allowable minimum wall thickness for the schedule of pipe being inspected.
This sample is expected to be completed by January 7, 1985.
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a Revision 2 dated August 31, 1984
- 22a -
Response to Item 3a (cont'd)
SLPPLEE NTAL RESPONSE _
Filler Metal Control Although there is no documented evidence as to which type of filler metal was utilized on each component, we believe the existing welds are acceptable based on the following:
A.
All of the carbon steel electrodes on the Braidwood site have a tensile strength of 70 ksi or greater. The only non-70 series electrodes purchased were two heats of E-6013 electrode. However, the Certified Material Test Reports for these two heats of E-6013 electrode indicate that each has a tensile strength greater than 70 ksi.
B.
A review of the Braidwood site records indicates that the following quantitles of welding materials were purchased for the Pullman Sheet Metal work.
TYPE OF FILLER METAL QUANTITY E-7018 12,875#
E-6013 1,350#
ER705-2 & E7-T-GS Wire 4,130 #
RCuSI-A 750#
E-308 & E-309 575#
ER-308 & ER-309 1,780#
The E-7018 filler metal constitutes over twice the amount of all the other welding electrodes on site. This is consistant with the Pullman Sheet Metal work scope because the hangers, braces, and auxiliary steel comprises 40% of the welding.
C.
Any misuse of silicon bronze filler metal would have been reported in the results of the visual weld inspection performed on all welds. Silicon bronze welds have a distinct gold color.
No cases were identified where this material was being used for the wrong application.
D.
The only other type of filler metal available to the welders was E-308 and E-309. This material does not produce a weld which is visually distinct from a E-7018 weld, and therefore the visual inspectlon program would not identify this condition. Although we believe the inadvertant use of stainless filler material on a carbon stcel component is unlikely, a statistical sample
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Revision 2 dated August 31, 1984
- 22b -
Response to Item 3a (cont'd) inspection was performed on the existing duct hangers to address this concern. The sample (which included hanger, auxiliary steel, and brace welds) was inspected for the presence of stainless filler metal using a magnet. No evidence of stainless steel filler metal was found in the sample.
Multipass Welding In order to provide additional assurance in the area of multipass welding, the following review will be performed in addition to the final visual inspection of the completed welds:
A.
Pullman Sheet Metal will perform a review of the Correction Notices generated prior to the implementation of in-process welding inspections in order to identify welders with a high rejection rate.
8.
Pullman Sheet Metal will identify the hangers that were welded by the identified welders with high rejection rates.
C.
These hangers will be reviewed to identify the existence of any multipass welds.
D.
The identified multipass welds will then be magnetic particle inspected to provide additional assurance beyond the final visual examination as to the acceptable quality of the completed welds, i
This sample program of multipass welds is expected to be completed by January 7, 1985.
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Revision 2 dated August 31, 1964
- 26a -
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Response to Item 3c (cont'd)
SLPPLEENTAL RESPONSE Inspection of base metal conditions during fit-up is currently performed during fit-up inspections. However, the procedure governing this visual weld inspection activity does not specifically identify surface and edge discontinuities as an attribute of the inspection.
In order to provide additional confidence in the inspection program, Pullman Sheet Metal Procedure 810.2.F " Visual Weld Inspection",Section IV.C.1, will be revised to formally include checking for surface and edge discontinuities during fit-up.
This procedure revision is expected to be completed by October 31, 1984.
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