ML20002C162

Forwards Revised Pages to Fsar,Reflecting Seismic Monitoring Program Status,In Response to NRC Request.Changes Will Be Incorporated in Amend 23 by Late Jan 1981

ML20002C162
Person / Time
Site:	Summer
Issue date:	01/07/1981
From:	Nichols T SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
NUDOCS 8101090489
Download: ML20002C162 (3)

Text

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i SOUTH CAROLINA Ettcinic a gas COMPANY m st errice een re.

COLumeiA, south CARoWNA 292!$

T. C. NicMots, Ja.

ug...... . a , cuem January 7, 1981 wuo. e .

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i Mr. Harold R. Denton, Director l Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

Virgil C. Summer Nuclear Station .

Docket No. 50/395 FSAR Changes

Dear Mr. Denton:

South Carolina Electric and Gas Company, acting for itself and as agent for South Carolina Public Service Authority, herewith forwards forty-five (45)

! copies of FSAR pages 2.5-64b and 2.5-64c which are being revised to reflect seismic monitoring program status.

These FSAR changes are being formally submitted at this time at the requst of the Staff, and will subsequently be incorporated into Amendment No. 23 in late January.

Very truly yours, 1

T. C. Nichols, Jr.

RBW:TCN:rh I

cc: V. C. Summer G. H. Fischer T. C. Nichols, Jr.

E. H. Crews, Jr.

0. W. Dixon, Jr.

l W. A. Williams, Jr.

O. S. Bradham i

D. A. Nauman R. B. Clary A. R. Koon 4pi g A. A. Smith J. B. Knotts, Jr.

J. L. Skolds B. A. Bursey

. NPCF/Whitaker

. File 8101090W7' (

d 60 mm/ min and a record duration of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, a WV radio receiver and other

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associated instrumentation. Seismic events to be conside:ced as having rele-vance are those with a local =agnitude (Fig) of 1.0 or greater and an (S-P) time of 4 seconds or less. /

The network was installed with a seismometer (Site 1) and a central recording station located on a peninsula on the east side of Monticello Reservoir, ap-proximately 2.5 miles NNE of the Virgil C. Summer Nualear Station. The three (3) other seismometers were located relative to Site 1 at approximately a 120* spacing as follows: Site 2 at approximately 10.2 miles SSE; Sita 3 at approximately 9.1 miles k'NW; and Site 4 at approximately 8.1 miles NNE. The three satellite seismometers are linked to the central recording station by telephone lines.

The recorded charts are changed daily and submitted to consultants to analyze the charts and to submit reports of their analysis on a quarterly basis, or on a monthly basis during periods of high seismic activity. Copics of these re-ports are submitted to NRC as they are available. T._ Applicant plans to to conGue. men'derin3 unth the. and ei MSZ .

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l After initial start-up problems, the network began supplying reliable data in December, 1977. Minor seismic adjustments to varying reservoir icvels j have been noted and are being analyzed and reported.

1 2.5-64b AMENDMENT bi 23 u._.., _,s g

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A USGS seisac=eter is also located about 3.2 miles ESE of the Virgil v

C. Su==cr Nuclear Station. This seis=ometer near Jenkinsville (JSC) which is monitored by the University of South Carolina, became opera-tional in November, 1973. The USGS seissc=eter provides additional coverage for the network and background infor=ation relative to seismic activity in the area.

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4 Identification of Active Faults There are no kacwn faul:s within 200 miles of the site which should be considered as " capable" faults as defined in Appendix A to 10 CFR 100.

Tha Relair Fault Zene, located approximately 75 :'iles southwest of the site, is still.under investigation as well as the newly discovered geologic features in the vicinity of Charleston, S. C. A more detailed' appraisal of the significance of tc..u fea ares is included in Sections 2.5.1.1, Regional Geology, and 2.5.2.6, Correlation of Epicenters with Geologic Structure.

2. 5. 2. 3 Description of Active Faults There are no known f aults within 200 miles of the site which should be

= sidered " capable" faults as defined in Appendix A to 10 CFR 1G0. For further information see Sections 2.5.1.1, Regional Geology, 2.5.1.2,

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.. Site Geology, and 2.5.2.7, Identification of Active Faults.

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