ML20070C291
| ML20070C291 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 06/28/1994 |
| From: | Carns N WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| WM-94-0099, WM-94-99, NUDOCS 9407050186 | |
| Download: ML20070C291 (3) | |
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W4$LF CREEK NUCLEAR OPERATING CORPORATION Neil S "Buzt Cams Ch+rman, President and cnie r m u m ort e June 28, 1994 WM 94-0099 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station F1-137 Washington, D. C. 20555 l l
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Reference:
- 1) Letter WM 93-0094, dated August 11, 1993, from i N. S, Carns, WCNOC, to NRC
- 2) Letter WM 94-0027, dated February 16, 1994, from N. S. Carns, WCNOC, to NRC
Subject:
Docket No. 50-482: Revision of the Inservice Inspection Summary Report for the Sixth Refueling Outage Gentlemen:
The purpose of this letter is to provide a revised page (page 12 of 79) for Reference 1. Reference 1 provided Wolf Creek Nuclear Operating Corporation's (WCNOC) Inservice Inspection Summary Report for the sixth refueling outage.
This summary report stated that relief requests would be submitted for the incomplete examinations of 19 components. Reference 2 provided relief requests for 18 of the 19 components; however, relief from the incomplete examination of component EBB 01A-16-W (Steam Generator "A" Steam Nozzle weld) was not requested at that time due to the expected receipt of a revision to ASME Interpretation IN89-026.
Interpretation IN89-026 concerned ASME Section XI, Code Case N-460 for volumetric examinations of Class 1 and Class 2 piping welds where interferences precluded the performance of the complete Section XI examinations. Code Case N-460 allowed a reduction in surface and volumetric coverage of Class 1 and 2 welds provided the reduction in coverage for a weld was less than 10 percent. Originally, Interpretation IN89-026 had stated that the total volume of weld permitted to be excluded by Code Case N-460 shall not exceed 10 percent when the exclusions from all required scans are combined additively.
Relief was to be requested for component EBB 01A-16-W due to an incomplete weld examination resulting from the steam nozzle to upper head weld configuration.
One hundred percent coverage of the weld was obtained from one side using the 45 degree and 60 degree beam angles, but only 92 percent (45 degree beam angle) and 78 percent (60 degree beam angle) was obtained from the opposite side. In addition, 100 percent coverage was obtained from the circumferential examination. Based on the first issuance of Interpretation IN89-026, it was concluded that this was an incomplete examination due to the combined exclusions exceeding 10 percent of the total weld volume.
9407050186 940628 'O Box 411/ Burbogton. KS 66839 / Phone. (316) 364 8831 /
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WM 94-0099 Pagt 2 of 2 Recently, Interpretation IN89-026 was revised by the ASME to state that the coverage of a wold is calculated using the average of all scan directions and beam angles together. Therefore, because of this revised interpretation, greater than 90 percent coverage of component EBB 01A-16-W was obtained and a relief request is no longer necessary to be submitted as originally stated in Reference 1.
. If you have any queations concerning this matter, please contact me at (316) 364-8831, e" tension 4000, or Mr. Richard D. Flannigan at extension 4500.
Very truly yours, Neil S. Carns NSC/jra Attachment cc: L. J. Callan (NRC), w/a M. A. Miller (NRC), w/a G. A. Pick (NRC), w/a W. D. Reckley (NRC), w/a l
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,htt$chment to WM 94-0099 l Corrective Action: A request will be submitted to the NRC asking that relief be granted for this limited examination.
EXAM LIMITATION:
TYPE CODE CODE XSI PLAN CQJiP_QNENT ID EXAM CA_L SECTION COMPONENT DESCRIPTION 83A1708 EBB 01A-SEAM-8-W UT C-A C1.20 Steam Generator "A" Shell Section D to Top Head Condition The volumetric examination of the subject weld is limited by positioning lugs (4) located every 90 degrees. The examination is limited in the axial direction in the following way 0.3% of the weld required volume (WRV) did not receive a 60 degree shear wave exam, 0.3% of the WRV received one direction 45 degree shear wave exam and 0.3% of the WRV received one direction 60 degree shear wave exam.
Corrective Action: None. Wolf Creek invokes Code Case N-460 which has been approved by the NRC for use on this site. This code case establishes that an examination of ninety percent or more meets the intent of ASME Section XI requirements when permanent interferences preclude a one hundred percent examination.
EXAM LIMITATION:
TYPE CODE CODE ISI PLAN COMPONENT ID EXAM CAT. SECTION COMPONENT DESCRIPTION 83A1708 EBB 01A-16-W UT C-B C2.21 Steam Generator "A" Steam Nozzle Condition: The volumetric examination of the subject weld is limited due to the nozzle blend interference on the nozzle side of the weld. Approximately 78% of the weld and base metal was examined with the 60 degree and approximately 90% is complete with the 45 degree examination.
Corrective Action: None. Wolf Creek invokes Code Case N-460 which has been approved by the NRC for use on this site. This code case establishes that an examination of ninety percent or more meets the intent of ASME Section XI requirements when permanent interferences preclude a one hundred percent examination.
EXAM LIMITATION:
TYPE CODE CODE ISI PLAM CQMfQ1LE_NT ID EXAM CAT. SECTION COMPONENT DESCRIPTION 83A1708 EBB 01d-SEAM-1-W UT B-B B2.40 Steam Generator "D" Bottom Heat to Tubesheet Page 12 of 79