ML20101L598
| ML20101L598 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 12/21/1984 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| NED-84-637, NUDOCS 8501020289 | |
| Download: ML20101L598 (2) | |
Text
I Georg;a Power Company 4
',o 333 Piedmort Avenue AHanta. Georg:a 303C8 Telephone 404 526 6526 Maarg Address.
Post Off:ce Box 4545 At!anta, Georg:a 30302 Georgia Power L. T. Gucwa the southern enfrc sys:em Manager Nuclear Engineermg and Ch.ef Nuclear Erg neer NED-84-637 December 21, 1984 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C.
20555 NRC 00CKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNITS 1, 2 SUPPLEMENTAL INFORMATION REGARDING DISCREPANCIES IN THE ANALYSIS OF THE SEISMIC FLOOR RESPONSE SPECTRA Gentlemen:
Georgia Power Company (GPC) pursuant to the request of Mr.
R.
A.
Hermann, Acting Licensing Project Manager for Plant Hatch, herein submits the following information to supplement our recent letter (NED-84-622 dated December 14,1984) concerning discrepancies in the analysis of seismic floor response spectra.
During the Part 10 CFR 21 evaluation of the discrepancies in the analysis of floor response
- spectra, a review of other engineering calculations was performed.
This review indicated that discrepancies may also exist in some cable tray support calculations.
These discrepancies involved the tracking of the weights of added cable and the attachment of conduit to existing cable tray supports.
Even though this may appear to cause the suports to be overloaded, the current tracking system is overly conservative since cables are assumed to run the entire length of the tray rather than the distance between the entrance and exit points of the cables in the tray.
Thus, supports are typically designed to support more weight than they actually support.
At this time, 258 cable tray supports have been analyzed for Unit 1 and 983 supports have been analyzed for Unit 2, and no reportable conditions have been found.
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8501020289 841221 g
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4 Georgia Power d Director of Nuclear Reactor Regulation Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C.
20555 December 21, 1984 Page 2 In addition, to provide further assurance, all suports on Unit 1 have been walked down to determine if any supports have potential problems. Only two supports were identified which were thought to possibly be of concern.
Both of these supports have been modified and will be evaluated for reportability in the future.
A load tracking program has been initiated to track increased loads due to both cables and conduits being added to supports.
In addition, any supports being designed in the future will be sketched "as-built" and evaluated for all loads.
Meanwhile, a program has been instituted to identify supports which have the greatest chance of being overstressed.
Once these supports have been evaluated, any findings will be reported per the cequirements of 10 CFR 21.
Georgia Power Company believes the above examination of supports pro /ldes a respresentative indication that a sufficiently high confidence level exists to indicate the units are being operated in a proper manner.
This confidence level and the load tracking program provides assurance that Georgia Power Company will properly investigate and review this concerns.
Yours very, hI h
L. T. Gucwa
/mb xc:
J. P. O'Reilly J. T. Beckham, Jr.
H. C. Nix, Jr.
Senior Resident Inspector l
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