ML19207B486
| ML19207B486 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 07/20/1979 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Whitmer C GEORGIA POWER CO. |
| References | |
| TAC-11158, NUDOCS 7908300036 | |
| Download: ML19207B486 (5) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION j
WASHINGTON, D. C. 20555 s.,*,.../
JblY J 1973 Docket No. 50-366 Mr. Charles F. Whitmer Vice President - Engineering Georgia Power Company Post Office Box 4545 Atlanta, Georgia 30302
Dear Mr. Whitmer:
We are centinuing our review of your sabmittal dated December 1,1978 which proposed Technical Specification changes for settlement of Class I structures on Hatch Nuclear Plant Unit No. 2.
We have determined that supplementary infomation, in addition to that requested by our letter dated March 30, 1979 is required. This infomation is identified in.
In order to provide for timely completion of our review we request that a revised submittal which includes the additional infomation identified in Enclosure 1 be provided within 30 days of your receipt of this letter.
Should you have any questions, please contact us.
Sincerely, i/ '
Thomas
. Ippelito, Chief Operating Reactors Branch #3 Division of Operating Reactors
Enclosures:
Request for Additional Infomation cc w/ enclosure:
see next oage 790830m%
yfo
s Mr. Charles F. Whitmer Georgia Power Company 2-cc:
G. F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N. W.
Washington, D. C.
20036 Ruble A. Thomas Vice President P. O. Box 2625 Southern Services, Inc.
Binningham, Alabama 35202 Mr. Harry Majors Southern Services, Inc.
300 Office Park Birmingham, Alabama 35202 Mr. William Widne~r Georgia Power Company Power Generatien Department P. O. Box 4545 Atlanta, Georgia 30302
- c. L. T. Gucwa Georgia Power Company Engineering Department P. O. Box 4545 Atlanta, Georgia 30302 Appling County Public Library Parker Street Baxley, Georgia 31413 Mr.
- k. F. Rogers U. S. Nucle;r Regulatory Commission P. O. Box 710 Baxley, Georgia 31513
ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION GEORGIA POWER COMPANY EDWIN I. HATCH NF LEAR PLANT UNIT NO. 2
" SETTLEMENT OF CLASS I S%UCTURES" A.
Paragraph 2.0 Settlement Measurement The following items are important and are not covered clearly in this section.
l.
Explain where the reference benchmarkt are located; what provisions have been made to avoid any displacement and/or settlement of the reference benchmarks; how and with what frequency are their elevations periodically checked.
2.
Explain the method used to determine the settlements, and possible horizontal displacements of other benchmarks with respect to the reference benchmarks.
3.
Indicate by means of sketchas the details of all the benchmarks:
location, shape, material, anchorage of benchmarks.
4.
Indicate on sketches the relative locations of all penetrations, including electrical penetrations, penetrations of ducts (if any) etc. with respect to the benchmarks. Discuss possible difference in values of actual settlements of penetrations and setticmc.its measured at benchmarks.
5.
Discuss whether the benchmark arrangement permits the computation of rotation, tilting and sliding of structures in addition to the vertical settlement.
6.
Total settlements since the beginning of construction are important.
However, as important are the settlemen+s which occur aftcr construction is finished and all the dead and live loads are installed.
Define the time elements for these occurrences with precision.
7.
Explain the exact meaning of the expression " average measured settle-ment".
Extreme values of settlements are as important, as the averages.
Provide these extreme values.
B.
3.0 Concarison of Predicted vs. Measured Settlements This comparison is important only as partial check on predictions and possibility to extrapolate for the entire life of the facility. Very important is also the assurance that the structures and all components, including electrical conduits and miscellaneous ducts can take the short range and long range settlements.
/
4 b
- Provide information relating to the consideration of tilting or rocking (in two different directions for adjacent structures),
rotation about horizontal axes, rotation about a vertical axis and sliding.
Include defonnations due to thermal gradients in soil, loss or gain of interstitial water, influence of seismic phenomena, floods, variations in underground water levels etc.
C.
4.0 Differentia.1 Settlements Across Structures 1.
Indicate the relationship in space between penetrations and bench-marks and discuss the possibility that the displacements of penetra--
tions may differ from the displacement of benchmarks.
2.
Same reasoning applies to differential displacements between buried elements and soil.
Indicate the relationship of the six components of displacements: 3 translations and 3 rotations.
3.
It is stated (4.1) that the limiting value for settlement profile of 0.002 has been established. Justify this value by establishing that all components are able to operate as required when this limiting value is reached. Consider, as indicated above, a combination of 6 component: of the displacement.
~
D.
5.0 Penetration Differential S_ttlements This section is not complete.
1.
As indicated in the discussion above cover all pipes, including valves, drains, electrical conduits, ducts, etc.
2.
Discuss the possibility that the displacements of penetrations differ from the displacement of the benchmarks.,
3.
Provide detailed sketches of anchors and their location with' respect to penetrations and details of anchors proper.
Indicate whether each anchor can take moments, shears, and axial loads, or only one or two of these systems of loads. Discuss thermal loads on anchors. Discuss whether they are constituted of snubber-like devices. Discuss the safety margins provided by the anchors including the sum of all loads as provided by standard loading combination equations (including differential displacements).
4.
The stress criterion indicated in 5.1 and taken from the ASME Boiler and Pressure Vessel Code, Section 3, Sub-section NC-3652.3(b),1977, is too narrow:
it covers only non-repeated loads on piping.
Provide additional criteria for at least the followag cases.
a.
sustained loads b.
dynamic loads n
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r
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. c.
materials not included in ASME Code (drainage pipes, concrete, sheetmetal) d.
electric induits e.
ducts f.
elbows 9
valves h.
connections in pipes, ducts, etc., especially welds, flanges and gaskets.
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