ML20215D416
| ML20215D416 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/10/1986 |
| From: | Nauman D SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20215D418 | List: |
| References | |
| NUDOCS 8612160356 | |
| Download: ML20215D416 (2) | |
Text
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December 10,1986 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission 1
Washington:DC 20555
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No.NPF-12 Heat Flux Hot Channel Factor (FQ)
Technical Specification Change
Dear Mr. Denton:
Since commercial operation of the South Carolina Electric & Gas Company (SCE&G)
Virgil C. Summer h uclear Station (VCSNS) in 1984, a number of steam generator tubes have been plugged. The majority of the tube problems which resulted in eventual tube plugging has been attributed to primary water stress corrosion cracking. Steam Generator tube pluggin g affects operation and is an important assumption within the plant's safety ana:ysis. From a safety analysis standpoint, the large break Loss of Cooling Accident (LOCA) analyses are limiting and are currently valid for steam generator tube plugging levels s:6%. At this level, only 83 additional steam generator (SG) tubes can be plugged in SG-B and still enable the VCSNS to remain within the bounds of the plant licensing basis.
Attached hereto is a technical specification revision to lower the maximum allowable Heat Flux Hot Channel Factor, Fq, from 2.32 to 2.25 beginning with Cycle 4 at VCSNS. This revision is in su,pport of an ongoing effort to provide safety analyses to support SG tube plugging levels in excess of 6%. Included as Attachment H is the Licensin g Significant Hazards Determination Form. Within the LOCA analyses, the adc itional peak clad temperature margin created by the Fq reduction will be used to offset the increase in peak clad temperature due to a higher SG tube plugginglevel.
j Upon approval of this Technical, Specification change, SCE&G will be in a position to support, in a timely manner, an increase in the allowable SG tube plugging level should it be required to support VCSNS operation. Should higher SG Tube Plugging levels not be required, these Technical Specification changes are in the conservative direction and impose a more restrictive plant surveillance requirement than has already been established.
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Mr. Harold Denton December 10,1986 Page Two The Technical Specification change has been approved by both the Plant Safety Review and the Nuclear Safety Review Committees. Please find enclosed the application fee of$150.00 required by 10 CFR 170.
The statements and matters set forth in this submittal are true and correct to the best of my knowledge, information and belief.
Ifyou require information regarding this Technical Specification revision, please contact Lou Cartin of my stafTdirectly at (803) 748-3106.
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DBM: DAN:bjh Enclosures c:
O.W. Dixon, Jr./f. C. Nichols, Jr.
E. H. Crews, Jr.
E. C. Roberts O. S. Bradham J. G. Connelly, Jr.
D. R. Moore i
W. A. Williams,Jr.
J. N. Grace Group Managers W. R. Baehr C. A. Price C. L. Ligon (NSRC)
R. M. Campbell i
K.E. Nodland R. A. Stough G. O. Percival l
R. L. Prevatte l
J. B. Knotts, Jr.
l H. G. Shealy NPCF File
.