ML20094C262
| ML20094C262 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 08/01/1984 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| 2NRC-4-114, NUDOCS 8408070432 | |
| Download: ML20094C262 (4) | |
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( 12 87 51 (412)923-1960 Nuclear Construction Division Telecopy (412) 787-2629 Robinson Plaza, Building 2, Suite 210 Pittsburgh, PA 15205 August 1, 1984 United States Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Mr. George W. Knighton, Chief Licensing Branch 3 Of fice of Nuclear Reactor Regulation
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Responses to Draft SER Open Items Gentlemen:
This letter forwards the attached responses to the NRC Geotechnical Engineering Section's Draft SER Open Item Nos. 180 and 181.
DUQUESNE LIGHT COMPANY By E L/J. Woolever Vice President JD0/wjs Attachuents cc:
Ms. M. Ley, Project Manager (w/a)
Mr. E. A. I.icitra, Project Manager (w/a)
Mr. G. Walton, HRC Resident Inspecter (w/a) i SUBSCRIBED AND SWORN TO BEFORE ME THIS
& DAY OF Oc/q
, 1984.
YG m
}L Notary Public ANITA ELA't;E F.EiTER, L'OTACY PUCUC ROBINSON TOWNSHIP. ALLEGliENY COUNTY MY COMMISSION EXP!RES OCTOBER 20,1986 h
Y 8408070432 840801 3g PDR ADOCK 05000412 E
P U;itcd Sectos Nucl2cr Regulctory Commission :
E
- Mr. G2crg2.W. Knightcn, Chiaf
.Page 2 COMMONWEALTH OF' PENNSYLVANIA )
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SS:
COUNTY OF ALLEGHENY
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On this
'J/a4 day of
/98
, before me, a Notary Public in and for said Commo(weal (h and County, personally appeared E. J. Woolever, who being duly sworn, deposed and said that (1) he is Vice (President of Duquesne Light, (2) he is duly authorized to execute and file the ! foregoing Submittal on behalf of said Cc,mpany, and (3) the statements 7 --
set' forth in the Submittal are true and correct to the best of his knowledge.
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' YL L
w Notary Public ANITA ELAINE REITER, NOTARY PUBLIC ROBINSON TOWNSPIP, ALLEGHENY COUNTY MY COMMISSION EXPIRES OCTOBER 20,1986 w
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Draf t.. 'SER 7 pen. Item No. 180 (Sect ion 2.5.5.3) - Soils Effective Strength 0
Parameters:
- The - applicant must. justify the use of ef fect ive strength parameters (i.e.,
_ effective friction
- angle, B,
and ef fective cohes ion,
c)
- in L the dynamic stability analysis where pe rmanent slope displacements are anticipated.
Response
The stability of the colluvial ~ slope was analyzed for static and dynamic b/
conditions.
Soil-properties under st at ic conditions are drained, or e f fective strests, properties - and under dynamic conditions are undrained,
or total stress, ~ propert ies.
Pore pressure ch anges will cause varia-tions'. in strength. propert ies based on the type of soil and groundwater conditions. present. _ For the colluvial slope south of the Emergency Outfall Structure (EOS), groundwatier is not present and the colluvial and alluvial soils in this area are not fully saturated.
In general, the site groundwater, level follows the level of the Ohio River (mean water' level. at elevation 665').
Since the EOS colluvial slope is well s
above the' groundwater, the in situ shear strength properties will be the same for the static and dynamic conditions.
The strength properties of the ' fine colluvial soil were cons ervat ively taken to be the residual friction angle with 'zero cohesion.
The prope rt ies were tre asured by laboratory tests that are described in the SWEC reoort entitled "Stabil-
- ity of Slopes at the Emergency Outfall Structure," June 1983.
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<Q Draft'SER Open Item No. 181 (Section 2.5.5.3) - Accuracy of SIDES Program:
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The.. dynamic stability analysis of the colluvial slope indicated a
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minimum factor < of ; safety of 0.8 for a circular arc within the fine
- grained colluvium.
Therefore, the applicant assumed that some movement of the' slope would occur in the event of. the SSE, and estimated the
' plastic. - (permanent) : displacement of the slope using a computer program SIDES : based on 'the Newmark model (Reference ' 6).
The acceleration time
, histories from.the El Centro 1940 earthquake (N-S. component) and the 1952 ' Kern - County. earthquake. (S69E component of the Taft record) were used ~in: this analysis..
The cumulative displacement of the slope predicted by ; the SIDES progr am (Reference 10) was le s s than an inch.
,-Although'-the magnitude of this movement is small, the applicant has been requested to document the accuracy of the analysis by furnishing an independent. verification of the SIDES program since it is a SWEC in-house program.
- Response:
[
IThe: computer program SIDES (Seismically Induced Displacements'of Embank-ments and Slopes) is described in the report prepared by Stone & Webster
( Engineering Corp. - (SWEC) 'for BVPS-2 entitled "St ability of Slopes ~ at the Emergency _ Outfall Structure,"' 1983.
This' program has previously been used 'in ; the design: of the Millstone Nuclear Power Station - Unit 3 (Northeast Nuclear. Energy Co.
1982) and the Shoreham Nuclear Power Station - Unit.1 (Long Island Lighting Co. 1976). ~ This program has been
. f ully. quali fied and documented. in accordance with SWEC engineering assurance procedures.
The qualification of the SIDES program invo lved
. checking the - program's. result s against results obtained by direct inte-gration of-the. equations of motion.
b
- Re feren'c es for Open Item 181 Long. Island Lighting Company 1976, Shoreham Nuclear Power Station -
1 Unit-1, Final Safety. Analysis Report, Docket 50-322, Appendix 2L,-
revised July 1977.
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2 Northeast, Nuclear Energy Company 1982, Millstone Nuclear Power St'at ion. -Unit 3,-
Final Safety. Analysis Report, Docket 50-423, Section 2.5.5.
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