ML20205H586
| ML20205H586 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 04/01/1999 |
| From: | Hughey W ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-90-05, GL-90-5, GNRO-99-00029, GNRO-99-29, NUDOCS 9904080319 | |
| Download: ML20205H586 (4) | |
Text
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Ente gy operations,Inc.
Port Gbson. MS 39150 1
Tel 601437-C470 W. K. Hughey Director Nuclear Safety & Regulatory A#ars April 1,'1999 U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C. 20555 Attention:
Document Control Desk
Subject:
Grand Gulf Nuclear Station Unit i Docket No. 50-416 License No. NPF-29 Relief Request ISI 2-01, Revision 1 GNRO-99/00029 Gentlemen:
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By this letter, Entergy Opera' ion, Inc. requests relief from the requirements of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, in accordance with 10 CFR 50.55a(g)(5)(iii).
A through wall leak was discovered in the tail pipe of the discharge relief valve for the Standby Service Water (SSW) "A" pump. The SSW "A" system was in service to support Shutdown Cooling (SDC) when it was determined that a code repair was necessary.
However, a code repair was determined to be impractical during this mode of operation. An evaluation in accordance with the guidance of Generic Letter (GL) 90-05 was performed to support continued operation. The pipe was subsequently replaced after the system was removed from service.
Even though the pipe has been replaced and compliance with ASME Section XI restored, strict compliance with 10 CFR 50.55a still requires licensee submittal and NRC approval of relief requests as described in GL90-05. Relief is therefore requested for the period of time that the temporary non-code repair was in effect.
j Yours truly, 5
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Ms. J. L. Dixon-Herrity GGNS Senior Resident (w/a)
Mr. L. J. Smith (Wise Carter) (w/a)
Mr. N. S. Reynolds (wla)
Mr. H. L. Thomas (w/o) 4 Mr. E. W. Merschoff (w/a) i
' Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Mr. S. P. Sekerak, Project Manager (w/2) l Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3-D i
Washington, D.C. 20555 I
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i ENTERGY OPERATIONS, INC.
GRAND GULF NUCLEAR STATION REQUEST FOR RELIEF FOR TEMPORARY NON-CODE REPAIR RELIEF REQUEST ISI 2-01, REVISION 0 4
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COMPONENTS IDENTIFICATION:
j Code Class:
ASME Code Class 3, moderate energy systems
References:
ASME Section XI,1992 Edition; 10 CFR 50.55a(g)(5)(iii);
Generic Letter 90-05, Guidance for Performing Temporary Non-Code Repair of ASME Class 1,2, and 3 Piping Examination Category:
D-B ltem:
D2.30 II.
IMPRACTICAL REQUIREMENTS:
l Section XI of ASME Boiler and Pressure Vessel Code (hereafter called the code) specifies code-acceptable repair methods for conditions that exceed code acceptance limits in code piping that is in service. A code repair is required to restore structural integrity regardless of the operational mode of the plant when the condition is detected.
Ill.
BASIS FOR RELIEF:
A through wall leak was discovered in the tail pipe of the discharge relief valve for the Standby Service Water (SSW) "A" pump. The pipe is 8" nominal diameter, schedule 40 with a design pressure of 10 psi and a design temperature of 90 degrees F. The flawed area is approximately %" in diameter. The wall thickness varies from nominal at the outer edges and tapers smoothly down to a small through wall hole near the center of the flaw.
The SSW"A" system was in service to support Phutdown Cooling (SDC) during a forced cutage when it was determined that a code repa.r was necessary. Because the pipe could not be isolated, a repair was not practical until SDC could be secured after plant restart.
The NRC has orovided guidance in Generic Letter (GL) 90-05 for acceptance of temporary non-code recairs for ASME Code Class 3, moderate energy piping. An evaluation was performed in accordance with the guidance in the GL to allow continued operation of the system. The evaluation concluded that the flaw meets the stability requirements specified in enclosure 1 of the GL and that the condition was acceptable for continued service. After plant start-up, SDC was secured and the degraded piping was replaced in accordance with code requirements.
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.e IV.
RELIEF REQUESTED:
According to the provisions of 10 CFR 50.55a (g)(5)(iii), relief from the impractical code requirement is requested for the period of time that the temporary non-code repair was necessary,
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