ML20244B874
| ML20244B874 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 06/07/1989 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-405, NUDOCS 8906140018 | |
| Download: ML20244B874 (2) | |
Text
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4 VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 June 7, 1989 U.S. Nuclear Regulatory Commission Serial No.89-405 Attn: Document Control Desk PES /ISI/FPB Washington, D.C. 20555 Docket No.
50-338 50-339 License No.
NPF-4 NPF-7 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT 1 AND 2 INTERVAL 1 INSERVICE INSPECTION PROGRAM ASME SECTION XI RELIEF REOUEST For North Anna Units 1 and 2, component examinations performed as part of the first interval inservice inspection program are performed in accordance with the requirements of ASME Section XI,1974 Edition, Summer 1975 Addenda. North Anna Unit 1 is currently in its last refueling outage of the first inspection interval. The pressurizer surge line nozzle-to-vessel weld was scheduled for examination during this outage. In preparation of performing this examination for Unit 1, it was discovered that the pressurizer heater cables and the heater cable penetrations attached to the pressurizer bottom head limit access and prevent meaningful examination of the nozzle-to-vessel weld.
Our first interval inservice inspection program submittals, transmitted by letter Serial No. 301, dated August 9,1977 for North Anna Unit 1 and letter Serial No.112, dated March 12,1979 for North Anna Unit 2, requested relief from the full volumetric examination of the pressurizer nozzle-to-vessel welds. Our relief aquests stated that we would alternately perform ultrasonic examinations to the extent practical.
Measurements of the examination area taken during this refueling outage have determined that approximately 3 to 8 percent of the weld volume may be ultrasonically examined. The dose associated with this partial examination is estimated to be 10 man-rem.
l Virginia Electric and Power Company feels the gain in system integrity is not commensurate with the exposure associated with this partial examination and the access restrictions described above also prevent other methods of volumetric I
examination. in addition, a satisfactory hydrostatic pressure test was performed on this weld area during the 1987 refueling outage. Therefore, we revise our relief request to I
now perform a system leakage test (VT-2 examination) of the pressurizer surge line nozzle-to-vessel welds on Units 1 and 2 as an alternative to the Code required 89o6140018 890607
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volumetric examination. The VT-2 examination of the nozzle to-vessel welds will be performed when the unit has reached naimal operating pressure and temperature.
In addition to the revised relief request above, Virginia Electric and Power Company takes ibis opportunity to inform you of another change to our first interval inservice inspection program. The component examinations for the first interval have previously been performed in accordance with the requirements of ASME Section XI,1974 Edition, Summer 1975 Addenda. However, in accordance with the provisions of 10 CFR 50.55L(g)(4)(iv), we Itave elected to perform certain examinations in accordance with the requirements set forth in a subsequent edition and addenda of ASME Section XI. Specifically, for ASME Section XI Class 2 Pump Casing Welds (Category C-F, item No. C3.1), we will be utilizing the examination rer;uirements and acceptance criteria of the 1983 Edition, Summer 1983 Addenda, of ASME Section XI (Category C-G, item No. C6.10). This edition and addenda of the Code has been selected because examinations performed during the second interval on Unit 1 are to be performed in accordance with the requirements of ASME Section XI,1983 Edition, Summer 1983 Addenda. The 1983 Edition of the Code requires a surface examination of Section XI Class 2 pump casing welds. Since the examination scheduled for this outage will be the first time this component has been examined, establishing a meaningful baseline would best be accomplished by utilizing those techniques that will be required during subsequent intervals.
The low head safety injection pumps are classified as ASME Section XI Class 2 and are constructed with casing welds. For Unit 1, the low head safety injection pump casing welds are scheduled for examination during the current refuelir.g outage. This is the last refueling outage for completion of the first interval inspection requirements for Unit 1. For Unit 2, the low head safety injection pump casing welds are scheduivd for examination during the third period of the first inspection interval, if you should have any further questions or require additional information, please contact us immediately.
Very truly yours, f
W. L. Stewart Senior Vice President - Power cc:
U.S. Nuclear Regulatory Commission Region ll 101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. J. L. Caldwell NRC Senior Resident inspector North Anna Power Station
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