ML20077J017
| ML20077J017 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 08/02/1983 |
| From: | Drummond F LOUISIANA POWER & LIGHT CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, W3I83-0260, W3I83-260, NUDOCS 8308120177 | |
| Download: ML20077J017 (3) | |
Text
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Laussiama 4.,ouAmoNo< S1eux P O W E R & L i G H T! P O eOX 6008
- NEW OALEANS LOUIS 1ANA 70174
- (504) 366 2345 mumn August 2, 1983 W3183-0260 Q-3-A35.07.74 Mr. John T. Collins, Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 E-5E Arlington, Texas 76012
SUBJECT:
Waterford SES Unit No. 3 Docket No. 50-382 Significant Construction Deficiency No. 74 "T-B Undersize Schedule 80 Socket Welds" Final Report
REFERENCE:
LP&L letter W3183-0210 dated June 15, 1983
Dear Mr. Collins:
In accordance with the requirements of 10CFR50.55(e), we are hereby providing two copies of the Final Report of Significant Construct ion De ficiency No. 74, "T-B Undersize Schedule 80 Socket Welds".
If you have any questions, please advise.
Very truly yours,
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,We **r F. J. Drummond Project Support Manager - Nuclear Attachment FJD/WAC/ MAL:keh cc:
- 1) Director 3)
Mr. E. L. Blake Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission l
Washington, D. C.
20555 (w/15 copies)
- 2) Director 4)
Mr. W. M. Stevenson Of fice of Management l
Information and Program Control U. S. Nuclear Regulatory Commission Washington, D. C.
20555 (w/l copy) 8308120177 830802 PDR ADOCK 05000382 S
PDR J t'- y 1
FINAL REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 74 "T6B UNDERSIZE SCHEDULE 80 SOCKET WELDS" INTRODUCTION This report is submitted pursuant to 10CFR50.55(e).
It describes a deficiency that existed in the socket weld size of schedule 80 small bore piping welds in ASME Class 2 and 3 piping systems. The ASME Section III socket weld dimensions were not complied with on all welds. This problem is considered reportable under the requirements of 10CFR50.55(e).
To the best of our knowledge, this problem has not been identified to the Nuclear Regulatory Commission pursuant to 10CFR21.
DESCRIPTION The piping contractor, Tompkins-Beckwith, Inc. through issuance of Nonconformance Report W3-5760, identified that socket welds on fittings and on flanges made by T-B on small bore schedule 80 piping did not meet the size requirements of ASME Section III.
Undersize welds were identified in various Class 2 and 3 i
piping systems.
SAFETY IMPLICATIONS The failure of these welds could have resulted in degradation of safety related systems thereby jeopardizing the safe operation of the plant.
CORRECTIVE ACTION TAKEN To determine the scope of the reinspection, a comprehensive review of piping stress analysis was conducted by Ebasco to identify critical welds in class 2 and class 3 piping systems. These critical welds were reinspected by T-B and any socket welds not meeting the ASME Section III code requirements were reworked.
Engineering determined that other undersized socket welds which were not determined to be critical by the analysis mentioned above could be accepted by applying ASME Code Case N316 (Endorsed by the NRC in Regulatory Guide 1.84).
It was determined that only two (2) out of approximately 535 welds inspected on fittings could not be accepted as is.
It was determined that the ASME Code Case N316 could not be applied to flange welds, therefore, all undersize flange socket welds were reworked per the ASME Section III code requirements.
l Because all of the undersized critical welds have been rev'rked to the
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requirements of ASME Section III and only two (2) welds os of the 535 initially inspected were undersized, it was determined that further 1 inspection of Schedule 80 socket welds on fittings was not required. To 4urther justify the l
.e i
1 SCD 74'(cont'd) elimination of a complete reinspection of schedule 80 socket fitting welds
- a finite element analysis was performed taking severely undersized socket welds not found in the field, but chosen by engineering as practical conditions for evaluation, and applying the actual worst case loading conditions found in the piping stress analysis for ASME Class 2 and 3 socket welded piping systems.
This was done in an effort to prove that even with the possibility of severely undersized welds exceeding the code case weld size limits, the' code allowable stresses would not be exceeded. This analysis verified this fact, but was not used to accept any undersized conditions found in the field.
A sample inspection of socket welds was also conducted on schedule 40 piping.
Some undersize welds were identified on flanges and were reworked per ASME Section III as described above. No undersize welds were identified on fittings.
The total of 97 socket welds including flange welds were reworked as a result lof the corrective action described above.
i All corrective action and documentation has been reviewed and accepted.
This report is submitted as the Final Report.
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