ML20112J444
| ML20112J444 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 03/29/1985 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8504050130 | |
| Download: ML20112J444 (3) | |
Text
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SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OFFICE 784 COLUMetA. SOUTH CARoWNA 29218 O. W. DixON JR.
VICE PnastOENT NUCLEAR OPERATION.
March 29, 1985 Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Comuission Washington, DC 20555
Subject:
Virgil C. Stauner Nuclear Station Docket No. 50/395 i
Operating License No. NPF-12 Microscismic Monitoring 14.twork
Dear Mr. Denton:
South Carolina Electric a Gas Company (SGM), acting for itself and or behalf of South Carolina Public Service Authority, hereby requests discontinuation cf the microseismic monitoring network at the Virgil C. Sumner Nuclear Station, on the basis that the minimtun requirements of Operating License Condition 2.C (24) have been satisfied, OprMlag License Condition 2.C (24) required SGaG to continue the seismic haniiu2 ring program until December 31, 1983, at which time there was to
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be a re-evaltration of the need for further monitoring.
Referring to attached Figure 1, the S &G microscismic monitoring network is composed of four (4) seismometers identified as Sites 1-4.
'Ihis network was installed in 1977 (prior to the impoundment of Monticello Reservoir) as required by the Nuclear Regulatory Comnission (NRC) in a Saf ety Evaluation performed in 1974 Station JSC (Jenkinsville, South Carolina)-is a permanent W ited States Geological Survey (USGS) seismometer installed in 1973 as part of the South Carolina state network. Station JSC was used from 1974-77 to identify the background natural seismicity in the area.
Since 1977, SGAG has used all five (5) seismometers to record and report the carthquake activity resulting f rom Reservoir Induced Seismicity (RIS) and natural events. After the peak RIS activity of 1978-79, data from the network have shown a steady decline of overall seismicity including the ntanber of events of magnitude 2.0 and larger. Tae seismicity levels are now approaching the pre-impoundnent background levels of 1974-77..
On this basis, SGaG proposes to continue the network monitoring with Sites 1-4 through December 31, 1985, after which time monitoring of these four (4) sites will be discontinued. Since Station JSC is a permanent USGS seismoineter, we would continue to review its data (through the Wiversity of South Carolina) in order to identify any changes in seismic activity levels. Additionally, SGaG proposes to discontinue the quarterly seismic reports to the NRC beginning in 1986. Any further reports will be prepared subject to significant increases in seismic activity levels as determined by Station JSC.
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~ March 29, 1985 Page 2 It is requested that the NRC Staff review this proposal and advise of its acceptability by September 1985, in order to allow SCEaG time to make arrangements with the involved parties. Please find enclosed the application fee of one hundred fifty dollars ($150.00) required by Title 10 of the Code of Federal Regulations, Part 170.
Should you have any questions, please contact us at your convenience.
Ver tru ur O. W.. Iron,gr.
RBW/vtw Attachment c:
V. C. Sunner T. C. Nichols, Jr./O. W. Dixon, Jr.
E. H. Crews, Jr.
E. C. Roberts W. A. Williams, Jr.
D. A. Natanan
,'. N. Grace Group Managers O. S. Bradham i
C. A. Price C. L. Ligon (NSRC)
K. E. Nodland R. A. Stough G. O. Percival C. W. Hehl J. B. Knotts, Jr.
H. G. Shealy NPG File f
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4 MONTICELLO RESERVOIR
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O V. C. SUMMER NUCLEAR STATION AJSC STUDY AREA A
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Figure 1