ML20213G251
| ML20213G251 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 11/07/1986 |
| From: | Nauman D SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| IEB-86-003, IEB-86-3, NUDOCS 8611170403 | |
| Download: ML20213G251 (2) | |
Text
r-South Cardna Electric & Gas Company Dan A. Nauman e
P.O. Box 764 Vce President Columb.
29218 Nuclear Operations SCE&G November 7,1986 BB t!DV 13 A B : 15 Dr. J. Nelson Grace Regional Administrator U. S. Nuclear Regulatory Commission Region ll, Suite 2900 101 Marietta Street, NW Atlanta, GA 30323
SUBJECT:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 NRC IE Bulletin No. 86-03
Dear Dr. Grace:
This report is provided in response to IE Bulletin 86-03, " Potential Failure of Multiple ECCS Pumps Due to Single Failure of Air-Operated Valve in Minimum Flow Recirculation Line".
Minimum flow recirculation lines installed at the Virgil C. Summer Nuclear Station do not have air-operated valves. However, the recirculation minimum flow paths associated with the Residual Heat Removal, Reactor Building Spray, Emergency Feedwater and Charging / Safety injection systems were evaluated in response to the subject bulletin.
The Residual Heat Removal, Reactor Building Spray and Emergency Feedwater systems were found not to have a single failure vulnerability in the minimum flow recirculation line.
Evaluation of the Charging / Safety injection (SI) pump minimum flow line l
identified a single-failure vulnerability. The discharge lines for each of the i
pumps are connected to a common recirculation header to provide a test flow path and a recirculation flow path for minimum flow at times when the reactor coolant system (RCS) exceeds the SI pump shutoff head. The common recirculation header is provided with a single motor operated valve (MVG 8106).
Spurious operations of MVG 8106 could result in loss of the recirculation flow path for minimum flow.
l The present design and Technical Specification requirements associated with the l
Charging / Safety injection pumps and the Pressurizer Safety Valves do not ensure minimal pump flow is maintained during events with potential repressurization.
A power lockout will be provided for MVG 8106 to preclude spurious o aeration from causing a loss of miniflow. This corrective action will be completec prior to startup following the fourth refueling which is presently scheduled for the last l
quarter of 1988.
I 8611170403 861107 (R
ADOCK 05000395 l
PDR o
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Dr. J. Nelson Grace November 7,1986 Page 2 in the interim, the present approved Emergency Operating Procedures provide 1
operator action which ensures Si pump flow will be above the minimal flow requirements.
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O. W. Dixon, JrJT. C. Nichols, Jr.
E. H. Crews, Jr.
E. C. Roberts O. S. Bradham D. R. Moore J. G. Connelly, J r.
W. A. Williams, Jr.
Group Managers W. R. Baehr C. A. Price W. T. Frady(NSRC)
C. L. Ligon R. M. Campbell, J r.
i K. E. Nodland R. A. Stough G. O. Percival R. L. Prevatte J. B. Knotts, J r.
l&E Washington NPCF i
File l
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