ML20214D430
| ML20214D430 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 11/14/1986 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| References | |
| SL-1565, NUDOCS 8611240081 | |
| Download: ML20214D430 (3) | |
Text
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Georgi 2 Fower Company 333 Piedmont Avenue Atlanta, Georgia 30308 Telephone 404 526-6526 Malling Address:
Fbst Office Box 4545 Atlanta, Georgia 30?O2 h
Georgia Power L T. Gucwa the scuterm Mrtrc sg. tem Manager Nuclear Safety and Licensing 0892C November 14, 1986 Director of Nuclear Reactor Regulation Attention: Mr. D. Muller, Project Director BWR Project Directorate No. 2 Division of Boilino "ater Reactor Licensing U.S. Nuclear Regulato.., Commission Washington, D.C.
20555 NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNITS 1 AND 2 CABLE TRAY SUPPORTS Gentlemen:
l On October 28, 1986, in a telephone conversation with Mr. R. D. Baker of Georgia Power Company (GPC), Mr. G. R. Rivenbark and Mr. C. P. Tan of the NRC requested that GPC submit additional information relative to the cable tray supports for Plant Hatch Units 1 and 2.
Enclosed please find the requested information.
If you have any questions regarding this matter, please contact this office at any time.
Sincerely, L. T. Gucwa p
/
JDH/lc Enclosure c: Georgia Power Company U.S. Nuclear Regulatory Commission Mr. s. P. O'Reilly
!Dr. sl. N. Grace, Regional Administrator Mr. J. T. Beckham, Jr.
fir. P. Holmes-Ray, Senior Resident Mr. H. C. Nix, Jr.
Inspector-Hatch GO-NORMS 0\\ -
.0 8611240001 861114
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PDR ADOCK 05000321
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k Georgia Power n ENCLOSURE NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 l
EDWIN I. HATCH NUCLEAR PLANT UNITS 1 AND 2 RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION RELATIVE TO PLANT HATCH CABLE TRAY SUPPORT DESIGN Question 1:
What is the approximate total number of cable tray supports in each unit?
Response
There are approximately 1800 Seismic Category I cable tray supports in Unit 1 and common areas, and approximately 1400 Seismic Category I cable tray supports in Unit 2.
Question 2:
What is the number of cable tray supports in each unit which meets FSAR criteria?
Response
Approximately 360 cable tray supports in Unit 1 have been shown to have stresses higher than FSAR allowables but lower than operability criteria allowables.
Therefore, at least 1440 Unit 1 supports meet FSAR criteria.
Note that, in most cases, the design of these 360 supports used loads in excess of the actual loads.
Only a few supports in Unit 2 have been analyzed using FSAR criteria.
The remainder of the supports has been evaluated using only the operability criteria.
- However, based upon previous analysis results, an estimated 350 supports in Unit 2 would have stresses in excess of FSAR allowables, thus leaving a total of 1050 supports which would meet FSAR criteria.
Questio,. 3:
What is the number of cable tray supports in each unit which use operability criteria damping values and meet FSAR stress criteria?
Response
In no case has a Unit 1 or Unit 2 cable tray support been evaluated using operability criteria damping values and FSAR stress allowables.
0892C E-1 11/14/86 700775
o Georgia Power d ENCLOSURE RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION RELATIVE TO PLANT HATCH CABLE TRAY SUPPORT DESIGN Question 4:
What is the number of cable tray supports in each unit which has been found acceptable using operability criteria?
Response
In Units 1 and 2, each Seismic Category I cable tray support (in its existing condition) has been shown to meet the operability criteria.
Question 5:
What is the number of cable tray supports in each unit that attains or is near the operability criteria allowables?
Give the actual calculated values.
Response
In each unit, only the cable tray supports chosen as the worst-case supports were evaluated in detail using the operability criteria.
All other supports were analyzed using conservative, simplified assumptions.
Even supports, which were analyzed in detail, may have used design loads in excess of the actual loads.
For Unit 1, 6 of 16 or 37.6 percent had calculated stresses in excess of 90 percent of operability criteria allowables.
For Unit 2, 7 of 19 or 36.8 percent had stresses in excess of 90 percent of operability criteria allowables.
The remainder of the supports had stresses lower than 90 percent of allowable or were analyzed using conservative methods; therefore, a comparison with allowables was meaningless.
0892C E-2 11/14/86 1