ML20003A575
| ML20003A575 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 01/30/1981 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8102040314 | |
| Download: ML20003A575 (2) | |
Text
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i rl SOUTH CAROLINA ELECTRIC a GAS COMPANY b
PC S T OF FjqE BOR,64 CotuMeiA, Souta CAROLINA 29218 January 30, 1981 T. c NicMots, Jn.
%CE Petsson.f A.D Geow* Dieumt Nuc6 tan Oat navec=s l2 L1 Mr. Harold R. Denton, Director Of fice Of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Seismic Monitoring Program
Dear Mr. Denton:
South Carolina Electric & Gas Company (SCE6G), acting for itself and as agent for the South Carolina Public Service Authority, has reviewed the seismic monitoring program presently established and commits to expand this program as follows. This program will remain in effect until the end of 1982, at which time an evaluation will be made to determine if it should be continued.
1.
We will continue operation of the seismic monitoring network at Monticello Reservoir, along with analysis of the data and quarterly submittal of the data to the NRC.
The qu arterly report will maintain its present format.
2.
We will inform the Operating Reactor Project Manager by telephone of the location, depth and magnitude of any unusual activity as soon as possible after the event. Unusual activity should be considered to be any of the following:
l Any earthquake larger than magnitude 2.5.
a.
b.
}bre than 100 seismic events per week.
i Any plans to change the water level in Monticello Reservoir to less than c.
415' elevation or greater than 430' elevation.
3.
We plan to install two (2) strong motion accelerometers in the free-field in the vicinity of the plant, one at the ground surface and one at bedrock.
If the accelerometer located on bedrock records an earthquake with a peak acceleration of at least 0.10g and with an interval of at least 1 second where peak acceleration exceeds 0.05g, then a copy of tha accelerometer re-cord along with its response spectrum and a calculation of its stress drop will be included in the quarterly reports.
4.
We will continue to look for correlations between seismicity and other vari-ables, such as water level changes, and report any possible correlations in the quarterly reports.
81020403W g
3 Mr. Ilarold R. Denton January 30, 1981 Page Two 5.
We will continue to stay abreast of the Wateree Creek fault mapping being conducted by USGS through the University of South Carolina and report to the NRC any findings.
SCE&G plans to implement the portions of this program which are not yet established as soon as possible.
In addition, these program commitments will be incorporated into the FSAR in the next amendment.
If there are any questions on this program, please let us know.
Very truly yours, x
/
T. C. Nichols, Jr.
RBW:TCN:glb cc:
A. A. Smith B. A. Bursey V. C. Summer G. H. Fischer W. A. Williams, Jr.
T. C. Nichols, Jr.
E. H. Crews, Jr.
II. N. Cyrus D. A. Nauman O. S. Bradham O. W. Dixon, Jr.
J. B. Knotts, Jr.
R. B. Clary A. R. Koon J. L. Skolds W. F. Kane R. E. Jackson A. J. Murphy D. J. Cash P. Sobel L. Reiter NPCF/Whitaker File 9