ML20128K209
| ML20128K209 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 02/10/1993 |
| From: | Antony D NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9302180100 | |
| Download: ML20128K209 (3) | |
Text
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Northern States Power Company 414 Nicolle: Mall Minneapoi:s. Minnesota $5401 Telephone 1612) 330 5530 February 10, 1993 10 CFR Part 2 Appendix C U S Nuclear Regulatory Cammission Attn:
Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLE.R GENERATING PIANT Docket Nos. 50-282 License Nos. DPR-42 50 306 DPR-60 Supplemental Reply to a Notice of Daviation NRC Inspection Report Nos. 282/92008 and 306/92008 Final Safety Analysis Report Commitment for Inservice Examination of High Energy Line Pinine
References:
1)
Letter from W D Shafer, U S NRC Region III, to L R Eliason, NSP, dated June 11, 1992 containing the Inspection Reports Nos. 50-282/92008(DRP) and 50-306/92008(DRP) i)
Letter from L R Eliason, NSP, to U S NRC, dated July 10, 1992, titled " Reply to a Notice of Deviation NRC Insnection Report Nos. 282/92008 and 30J/92008 Final Safety Analysis Report Commitment for Insenrice Examination of High Energy Line Piping" 3)
Letter from W D Shafer, U S NRC Region III, to L R El'eson, NSP, dated July 29, 1992, titled " Notice of Deviation (NRC Inspection Report No. 50-282/92008; 50-306/92008(DRP))"
Pursuant to the provisions of 10 CFR Part 2, Appendix C, the following is submitted as an additional response to the notice of deviation contained in your letter of June 11, 1992 (Reference 1).
In our original response (Reference 2) to the deviation, as part of our corrective action, we had committed to the following:
During the two unit outage, scheduled for Fall, 1992, the not 1
Inservice Inspection program for welds in high energy piping in the Auxiliary Building will be augmented to include additional weld inspections in the main steam and feedwater lines.
Selection of the welds for inspection will be based on stress levels calculated in the Plant Design Stress Analysis Reports.
Those arcas of highest stress, which are not encapsulated, will oe inspected.
09' 9302180100 930210 PDR ADOCK 03700282 ll
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PDR A
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Northem States Power Company U S. NRC
- Page 2 of 3 February 10, 1993 Following the original response, we held discussions with the Senior Resident Inspector for Prairic Island regarding the welds to be selected. We received your letter (Reference 3) which documented those diseassions:
Concerning corrective action, you stated you would select additional welds in areas of highest stress for supplementary inspection during the fall, 1992, outage.
Based on further clarifications made during discussions between our respective staffs, it is our understanding that the supplementary inspection shall apply for at least one additional weld in j
each major piping size, such that not less than five additional steam piping welds nor less than five' additional feedwater piping welds shall be examined.
Subsequent to these discussions and letters, we determined that it would be more informative to examine welds selected from lines which experienced full j
time operation rather than selecting welds on bypass or shut down lines.
This i
was in conflict with the commitment as discussed above.
Therefore, we held further discussions with Region III staff, prior to performing the 4
examinations, to explain our revised plans and our rationale.
This letter l
documents the change in plans and provides the list of welds that we examined.
The following list of welds were inspected during the Fall 1992 outage:
System Weld #
Stress High Operating Stress (psi) within This System (pni)
=
l Main Steam, Unit 1 MS-11 14347 24107 MS-28 11898 l
MS-38 16556 i
MS-81 10985 MS-82 9245 Main Steam, Unit 2 MS 21 14355 17018 MS-49 11710 MS-50 11052 1
MS-81 17018 MS-160 15085 4
r
U f NRC' Northern States Power Company Page 3 of 3 February 10, 1993 System Weld #
Stress High Operating Stress (psi) within This System (psi)
Feedwater, Unit 1 FW 53 13800 18365 EV-95 18365 (94)
FW-144 11045 FW-145 12829 FW-221 12644 (146)
Feedwater, Unit 2 FW-1 18960 27848 FW-i 16004 FW-108 13125 FW-114 15069 FW-115 17004 The welds examined were the highest stressed welds that were accessible.
Some high stress welds were inaccessible due to encapsulation or rest raints. One high stress veld was rendered inaccessible due to the difficulty of installing i
an asbestos removal containment structure in a high traffic area.
Examination results were satisfactory (i.e., there was no evidence of service induced degradation).
In summary, we'have modified our commitment regarding the additional wc1d examinations scheduled for the Fall 1992 outage:
from one additional weld of high stress in each major pipe size, for each main steam and feedwater trait per unit, to the five highest stressed accessible welds which experience full-time operation, for each main steam and feedwater train per unit (all five could be in the same pipe size). The one incomplete commitment (revising the Updated Safety Analysis Report) from our original response (reference to) will be completed by June 30, 1993, as discussed in Reference 2.
Please contact Jack Leve111e (612-388-1121, Ext. 4662) if you have any ques n
la ed to this letter.
/ 4)ny)
Douglas D Antony Vice President Nuclear Generation c: Regional Administrator - Region III, NRC Senior Resident Inspector, NRC NRR Project Manager, NRC J E S11 berg
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