ML20042A447
| ML20042A447 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 03/16/1982 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM NUDOCS 8203230427 | |
| Download: ML20042A447 (2) | |
Text
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s-SOUTH CAROLINA ELECTRIC a GAS COMPANY Post orrect son 7s4 CotuMeiA, Souf H CAROLINA 29218 t
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March 16, 1982 l', '
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Mr. Harold R. Denton, Director k:
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Subject:
Virgil C. Sumer Nuclear.J \\ tion v
Docket No. 50/395
'IMI Item II.F.2
Dear Mr. Denton:
In our letter dated June 8, 1981, South Carolina Electric and Gas Conpany (SCE&G) provided a point by point response to NUREG 0737 Item II.F.2 which described in detail the inadequate core cooling instrumentation to be used at the Virgil C. Sumer Nuclear Station. That response included schedules for installation and qualification of the various conponents. The installation and qualification for 16 incore thermocouples, cabling, reference junction boxes and connectors was scheduled for June,1983.
In our letter dated January 18, 1982, SCE&G addressed the NRC position expressed in the Virgil C. Sumer Safety Evaluation Report Supplement 3 page 22-3, that this schedule was unacceptable, stating that the schedule was contingent upon equipment delivery. At the request of Mr. Tai Huang of the NRC we are providing the following additional justification for that schedule.
Should the existing incore thermocouple interface to the subcooling nonitors fai1 to function properly as a result of a seismic event or a harsh environnent from a high energy pipe break, other indications are available to detect inadequate core cooling. The subcooling monitors also calculate and indicate the subcooling margin based on the qualified hot leg RID tenperature inputs independent of the incore thernoccuple inputs. The operator also has qualified wide range pressure and tenperature indications available for use in manually calculating the subcooling margin. The reactor vessel level instrunentation system provides additional diverse indication of inadequate core cooliry.
The incore thermocouples, reference junction boxes and connectors are being qualified by Westinghouse in a generic program.
Identical thermocouples to those used at the Virgil C. Sumer Nuclear Station are being tested as a part of this program eliminating the need for their replacement. New reference junction boxes and connectors are being designed, bought and qualified by Westinghouse. The qualification should be conplete early in 1983 with hardware available for installation in June, 1983. SCE&G is purchasing qualified thernoccuple cable to complete the circuits from the new qualified connec. tors gOg\\
at the reactor vessel head to the new reference junction boxes. Qualified penetrations and cable are available for the circuits from the reference junction boxes to the subcooling monitors.
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Mr. Harold R. Denton March 16, 1982 Page 2 In the unlikely event that the incore thermocouples should fail it is the SCE&G position that adequate additional information and procedures exist to detect and recover from inadequate core cooling. We therefore believe full power operation is justified until the new qualified equipment can be installed during the first major shutdown or refueling outage following June,1983. We hereby request relief on the 'IMI item II.F.2 fuel load requirement.
If you have any further questions, please let us know.
Very truly yours, A
T. C. Nichols, Jr.
SC:'ICN:lkb cc:
V. C. Sumner G. H. Fischer H. N. Cyrus T. C. Nichols, Jr.
M. B. Whitaker, Jr.
J. P. O'Reilly H. T. Babb D. A. Nauman C. L. Ligon (NSRC)
W. A. Williams, Jr.
R. B. Clary O. S. Bradham A. R. Koon M. N. Browne G. J. Braddick J. C. Ruoff J
J. L. Skolds J. B. Knotts, Jr.
B. A. Bursey J. B. Cookinham NPCF File