ML20133N168
| ML20133N168 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 10/15/1985 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| 2178N, NED-85-726, NUDOCS 8510280420 | |
| Download: ML20133N168 (3) | |
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f NED-85-726 2178N October 15, 1985 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 OPR-57, NPF-5 EDWIN 1. HATCH NUCLEAR PLANT-UNITS 1 AND 2 VERIFICATION OF OPERABILITY OF CABLE TRAY SUPPORTS Gentlemen:
Georgia Power Company's (GPC) letter NED 85-353, dated April 30, 1985, provided an update of the long-term program for corrective action associated with our cable tray support verification program previously detailed in letters NED 84-641 and NED 85-032, dated December 28, 1984 and January 16, 1985.
As noted previously in that correspondence, the objective of the program is to verify that the seismic qualification of safety-related cable tray supports meets the requirements specified in the appropriate Plant Hatch Final Safety Analysis Report (FSAR).
If a support could not be shown to meet these requirements, the support would be evaluated against the operability criteria included previously as an attachment to our letter NED 84-641 to determine reportability.
In addit'on, the support would be modified to meet FSAR criteria.
The current status of the program is:
Unit 1 Letter NED 84-641 stated that sixty supports on Unit I were chosen from a field walkdown conducted to choose the most critical supports.
In reporting the preliminary results of the evaluation of these sixty supports, letter NED 85-353 stated that twenty-six met FSAR criteria, twenty-eight met the operability criteria, and six were under evaluation pending receipt of additional field data.
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k Georgia Power n Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 October 15, 1985 Page 2 Since receipt of this field data, analysis of these six supports has continued. The analysis techniques consist of modeling entire cable tray support systems using finite element models, as well as time-history analysis.
The techniques are rigorous and complex and, therefore, more time consuming than the methods originally used to analyze the entire sample of sixty supports.
Due to the fact that this sample of sixty supports represents the most critical supports, we felt it was necessary to continue the analysis of these six supports in order to have complete information concerning the actual bounding values for each of the support types identified in the sample. To date, the results obtained by applying additional sophisticated techniques to these six supports demonstrate that one meets the operability criteria, while five remaining supports are still undergoing analysis.
While analysis using sophisticated techniques may show the five supports currently under evaluation meet the operability criteria, they have recently been modified to meet FSAR criteria.
In addition, design modification packages to bring the other twenty-nine supports into compliance with the FSAR have been sent to the Hatch plant site for implementation.
Completion of these modifications is scheduled prior to startup for fuel cycle number eleven.
Based on the results of the initial walkdown, a follow-on walkdown of accessible areas in Unit I nas been conducted. Inaccessible areas will be walked down during the 1985 fall refueling outage.
The evaluation of the results of this follow-on walkdown will be completed by February 28, 1986, and the results with an outline of future plans will subsequently be sent to you.
Unit 2 Letter NED 85-353 stated that forty-two supports on Unit 2 were chosen for evaluation through a field walkdown conducted to choose the most critical supports.
During a recent refueling outage, three additional supports were added to the group of most critical supports through a walkdown of inaccessible areas.
Preliminary results of the evaluation of these forty-five supports show that eleven meet FSAR criteria.
Of the remaining thirty-four supports, twenty-three meet the operability criteria and eleven are under evaluation.
Modification design packages are scheduled to be provided to the site for implementation for these thirty-four supports by June 30, 1986.
These modifications are scheduled to be completed prior to startup for fuel cycle number eight.
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k Georgia Power h Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 October 15, 1985 Page 3 A follow-on walkdown has been scheduled for Unit 2 in light of the results of the initial walkdown.
The estimated date for completion of the inspection phase of this follow-on activity for normally accessible supports is April 30, 1986.
Inaccessible supports will be examined prior to startup for fuel cycle seven.
As previously mentioned in letters NED-85-032 and NED-85-353 a modification or evaluation schedule will be sent to you upon completion of the Unit 2 follow-on walkdown.
As previously stated, all supports on both units not in accordance with applicable revised FSAR criteria will be modified to bring calculated stresses to within allowable values.
In addition, GPC will notify the NRC if any reportable condition is founo. We believe the program to examine supports and the load tracking program presently in place will ensure that all supports will be brought into compliance and will continue to meet the criteria stated in the FSARs.
Yours truly, f,n_ =
L. T. Gucwa OMS /caa xc:
J. T. Beckham, Jr.
H. C. Nix, Jr.
J. N. Grace (NRC - Region II)
Senior Resident Inspector w:s
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