ML20237J469
| ML20237J469 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 08/13/1987 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR GL-87-02, GL-87-2, SL-2866, NUDOCS 8708180190 | |
| Download: ML20237J469 (2) | |
Text
' Georgia fbwer Cornpany '
i**
333 Piedmont Avenue
~ 'r.
Atlanta, Georgia 30308 '
Telephone.404 526 6526 Malling Address.
q Post Office Box 4545 g
Atlanta, Georgia 30302 Georgia Power L. T. Gucwe.
tire souttwrn eixtnc system Manager Nuclear Safety and Licensing.
SL-2866 1517C X7GJ17-H210 X7GJ17-H220 August 13, 1987 1
.U.S. Nuclear Regulatory Commission ATTN:. Document Control Desk Hashington, D'C.
20555 PLANT HATCH - UNITS 1, 2
'NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 GENERAL ELECTRIC MODEL HGA RELAYS Gentlemen:
Recently, based upon conversations with another utility, we became aware of' potential seismic capability concerns related to HGA 11 and HGA 111 relays.
The specific concerns with these components are documented in General Electric Service Advisory Letter (SAL) number 721-PSM-174.1.
It is our understanding that the NRC has a. copy of the subjectSAL.
Georgia Power Company has performed evaluations to determine whether a potential safety problem exists.
Specifically:
o Recently Plant Hatch was analyzed (with the new LOCA evaluation model, SAFER /GESTR) utilizing a 24-second delay between event initiation and the powering of the emergency buses by the diesel generators.
The licensing peak cladding temperature for Plant Hatch was determined to be approximately 1530'F.
This provides substantial margin, over 600*F, to the 10 CFR 50.46 limits of 2200*F.
Strong earthquake motion (
Reference:
Hatch Unit 2 FSAR Section 3.7. A.3.1.2 and FSAR Figure 3.7A-3) is expected to occur for only 4-6 seconds.
Even if the earthquake were postulated to occur simultaneous with the LOCA, sufficient time exists (after the strong motion subsides) for the relays to perform their safety function and the ECCS to mitigate the event.
o Plant Hatch is a member of the Seismic Qualification Utility Group (SOUG).
This utility group is preparing a generic resolution to USI A-46 as discussed in the enclosure to NRC 8708180190 870013 gh PDR ADOCK 05000321 F
.9 Georgia'Powerk
- q U. S. Nuclear Regulatory Commission August.13, 198' Page-Two-Generic Letter 87-02.
As part of this developing generic resolution there will be procedures for evaluating Nuclear Power Plant relay seismic functionali ty.
These procedures will be implemented as part of.the total generic resolution to USI A-46 after final approval of all procedures by SQUG.
' Based upon the above information, - Georgia Power Company does not believe' that~ additional efforts would be beneficial at this time. and, therefore, intends -to defer this item to the resolution of USI A-46 via the ongoing SQUG efforts.
j If you have any questions regarding this matter, please contact this office at any time.
Sincerely, f&
L. T. Gucwa MJB/lc c: Georgia Power Comoany Mr. J. P. O'Reilly, Senior Vice President - Nuclear Operations Mr. J. T. Beckham, Jr., Vice President - Plant Hatch GO-NORMS U.S. Nuclear Reaulatory Commission. Washington. D.C.
Mr. L. P. Crocker, Licensing Project Manager - Hatch U.S. Nuclear Regulatory Commission. Reaion II Dr. J. N. Grace, Regional Administrator Mr. P. Holmes-Ray, Senior Resident Inspector - Hatch 1517C 700775