ML20058F156
| ML20058F156 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/31/1990 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 90-652, NUDOCS 9011080122 | |
| Download: ML20058F156 (2) | |
Text
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VIHOINIA ELECTHIC AND POWER COMI'ANY j
RicunoNo,V norNIA 20061 October 31,1990 U.S. Nuclear Regulatory Commission Serial No.
90 652 Attention: Document Control Desk NES/ISI/EWT:jbl R1 3
Washington, D.C. 20555 Docket No.
50 339 License No.
N?F-7
{
Gentlemen:
ylRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT 2 i
INSERVICE INSPECTION PROGRAM RELIEF REQUEST FROM ASME SECTION XI REQUIREMENTS SAFETY INJECTION ACCUMULATOR VESSEL WELD EXAMINATION
- Pursuant to 10 CFR 50.55a(g)(S), relief is requested from certain code requirements described in IWC-2500 and-lWC-2600 of ASME Section XI.1974 Edition, Summer 1975-Addenda, associated with the safety injection accumulator tanks for North Anna C
-Unit 2l-The relief is required for North Anna Unit 2 for the first inspection interval which ends on December 14,1990. The basis for our request is provided below.
The current North Anna Unit 2 refueling outage is also the ten-year Inservice Inspection outage where the final examinations required by ASME Section XI for the first inspection interval are being conducted. Some of'the welds scheduled to be examined during this outage are on the safety injection accumulator tanks (2-SI-TK-1 A,1B, and 10). However, the condition of these welds prevents full volumetric examination coverr4.e (i.e., Code Case N-460 requires at least 90% of the required volume be examined) The welds must be prepared by grinding the surface smooth to ensure complete excmination coverage. 'A partial examination of each weld was conducted in the Es-welded condition. Thece partial examinations resulted in no recordable Indications. (The documentation for these partial examinations is available
'upo equest.)
We asesrt that full volumetric examination of the accumulator tank welds is impractical.
. The surface preparation necessary to perform the examination (i.e., grinding the surface smooth on a vesselinside containment) is unnecessary in this case. These examinations are required 'oy the 1974 Ed! tion, Summer 1975 Addenda, of ASME Section XI. However, the accumulator tanks are statically pressurized vessels with no pumps in the~ process flow path. Vessels of this type were exempted from examination -
. requirements in the 1986 Edition of the Code (paragraph IWC-1221(e)). In addition, the second. ten-year inspection interval for North Anna Unit 2 begins December 14, 1990. In accordance with 19 CFR 50.55a(g)(4)(ii), the second Interval Inservice Inspection' program _ plan is required to meet the examination requirements of the 1986 9011080122 901031
/)O 4/ 7 gDR ADOCK 0500 9
t
x l-Edition of ASME Section XI. Hence, the vessel welds will not be required to be examined in futuie inspection program plans.
Therefore, it is requested that the first interval volumetric and surface examination requirements on the safety _ injection accumulator tanks (2-SI TK 1 A,1B, and 1C) be considered complete with only a partial examination being performed.
- This relief request has been reviewed and approved by the Station Nuclear Safety
-and Operating Committee.
Should you have any questions or require additionalinformation, please contact us.
Very truly yours, W. L. Stewart Senior Vice President - Nuclear
- cc:
U.S. Nuclear Regulatory Commission Region II
-101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. M. S. I. esser NRC Senior Resident inspector North Anna Power Station i
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