ML17258B154
| ML17258B154 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 06/30/1981 |
| From: | Maier J ROCHESTER GAS & ELECTRIC CORP. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-02-04.D, TASK-2-4.D, TASK-RR NUDOCS 8107080192 | |
| Download: ML17258B154 (9) | |
Text
I c'EGULATO INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR: 810708019~
DOC. DATE: 81/06/30 NOT IZED:
NO DOCKET 0, FACIL:50-244 Robert Emmet Ginna Nuclear Planti Unit ii Rochester G
05000244 AUTH. NAME AUTHOR AFFILIATION MAIERzJ. E.
Rochester Gas Sc Electric Corp.
REC IP. NAME RECIPIENT AFFILIATION CRUTCH=IELD> D.
Operating Reactors Branch 5
SUBJECT:
Forwards assessment of SEP Topic II-4. Dz "Stability of Slopesi" per NRC 810417 ltr. Slopes near plant site are in stable condition.
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89 EAST AVENUE, ROCHESTER, N.Y. 14649 JOHN E.
MAIER VICE'RES I DENT TCLEPHONK AREA COOC 7le 546.2700 June 30, 1981 Director of Nuclear Reactor Regulation Mr. Dennis M. Crutchfield, Chief Operating Reactors Branch No.
5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
SEP Topic II-4.D, Stability of Slopes R.
E. Ginna Nuclear Power Plant Docket No. 50-244 x~ (0 I
Dear Mr. Crutchfield:
Attached is Rochester Gas and Electric assessment of SEP Topic II-4.D, "Stability of Slopes."
The format for this assess-ment was derived from the NRC staff's assessment of this topic for the Palisades plant, transmitted by letter dated April 17, 1981 from Dennis M. Crutchfield, NRC, to David P.
Hoffman, Consumers Power Company.
Very truly yours, Jo n E. Maier Attachment po><
'107080192 810630 PDR ADQCK 05000244'I
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Attachment SEP Safety Topic Evaluation R.
E. Ginna Nuclear Power Plant Unit I Topic II-4.D Stability 'of Slopes Introduction In order to assure that all safety related structures, systems and components are adequately protected against the failure of natural or man-made
- slopes, the possibility of move-ment of these slopes is evaluated by comparing forces resisting failure to those causing failure.
The scope of this safety topic evaluation is to review the condition of existing slopes, including geotechnical properties, ground water table, etc.,
and, using current review criteria as a basis, to evaluate adequacy of these slopes.
Current Review Criteria are:
The current review criteria for this specific safety topic 1.
2.
SRP 2.5.5 Appendix A to 10CFR Part 100 Related Sa fet Topics and Interfaces 1.
2.
3.
SEP Topic II-3.A Hydrology Description SEP Topic II-4, Geology and Seismology SEP Topic III-1, Classification of Structures, Components, and Systems Evaluation The final grading of the plant site has left only two slight onsite slopes.
One slope toe, elevation 260, is located approxi-mately two hundred feet northwest of the Turbine Building and extends out nearly one hundred and fifteen feet while rising fifteen feet to elevation 275.
The second slope is located east of the Screen
- House, elevation
- 255, and extends to elevation 265.
Both slopes are graded at approximately 7.5 horizontal to 1
vertical.
These slopes are located in silty clay soil with occasional scatterings of sand and gravel throughout.
The water table is approximately five to twenty feet below the surface.
The figure supplied via Reference 6 is a plot plan showning rock surface and ground water contours.
The factor of safety for the stablity of these slopes can be estimated based upon infinite slope theory.
Based on the infor-mation provided in Reference 7, the friction angle of silty clay is estimated to be 32 degrees.
Using a friction angle of 32
4
degrees and the slope of 7.5 horizontal to 1 vertical, the factor of safety is computed to be 4.7, in accordance to the methodology presented in Reference 8.
This factor of safety greatly exceeds the factor of safety value of 1.5 that is recommended in SRP 2.5.5.
RG&E thus concludes that, because of the 4. 7 factor of
- safety, the absence of any potentially adverse ground water conditions, and the good performance of these slopes since construction, the onsite slope conditions can be considered
stable.
Conclusion Based on the information provided in the references and the above evaluation, we conclude that the slopes at the R.
E. Ginna site are in stable condition.
l 4
7 I
1
References Dames 6 Moore, "Geologic and Geophysical Investigations, Ginna Site, Ontario, New York" prepared for Rochester Gas 6
Electric Corporation,
- February, 1974.
Dames 6 Moore "Proposal, Site Evaluation Study, Proposed Power Plant, Rochester, New York", Rochester Gas 6 Electric Corporation.
Rochester Gas and Electric Corporation, "Brookwood Nuclear Station Unit No. 1, Preliminary Facility Description and Safety Analysis Report",
- March, 1966.
"Rochester Gas and Electric Corporation, R.
E. Ginna, Nuclear Power Plant Unit No. 1, Environmental Report" Volume 2,
- August, 1972, Submitted to United States Atomic Energy Commission, Docket No. 50-244.
Rochester Gas and Electric Cproration "Robert Emmett Ginna,,
Nuclear Power Plant Unit No. 1, Final Facility Description and Safety Analysis Report" Volume 1, November, 1968.
- Letter, John E. Maier, RG&E, to Dennis M. Crutchfield,
- NRC, SEP Topics III-3.A, II-3.A, II-3B. II-3.B.1, and II-3.C, dated May 1, 1981.
Soil Mechanics, Lambe and Whitman, P.
307.
Soil Mechanics and Foundations, Parcher and Means, P. 483.