ML20063L318
| ML20063L318 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 09/03/1982 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-PT21-82 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8209090053 | |
| Download: ML20063L318 (4) | |
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o SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OFPICE 764 COLUMSIA. SOUTH CAROLINA 29218 O. W. DixON. JR.
Septenber 3,1982 vice p....o ar NucLean OPanatiONS Mr. James P. O'Reilly, Director U. S. Nuclear Regulatory Comission Region II, Suite 3100 101 Marietta Street, N.W.
Atlanta, GA 30303
Subject:
Virgil C. Sumer Naclear Station Docket No. 50/395/J Operating License No. NPF-12 Reportable Substantial Safety Hazard Solid State Protection System On-Line Test Circuit N
'I
Dear Mr. O'Reilly:
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.z On August 5, 1982, the NRC was notified of a substantial safety hazard 2:0 concerninganundetectablefailurewhichcouldexistintheon-linetEting[]O circuits of the Solid State Protection System. 'Ihis prtblem was id ified ;D by Westinghouse, and South Carolina Electric and Gas (SCS G) was fir infoj$$il on August 4,1982. 'Ihe attached information includes a description.and an hllj evaluation of the problem.
e y y; ss Although failure of the subject test switch contacts is highly inprobable, SCSG will revise the surveillance test procedure to verify contact closure as an interim fix until Westinghouse coupletes a review of its consideration of design changes.
'Ihis letter represents the thirty (30) day report by SCE&G on this substantial safety hazard which is being reported under the reqairenmit of 10CFR50.55(e). We expect to make a final report by Decenber 1,1982.
Very trul yours,
)
O. W. Dixon, Jr.
JCL:OWD:tdh Attachnent cc: see page two f OFFICIALCOPYd y
8209090053 820903 gDR ADOCK 05000 ggg
=
Mr. J. P. O'Reilly Page two September 3, 1982 l
cc:
V. C. Sunmer T. C. Nichols, Jr.
G. H. Fischer O. W. Dixon, Jr.
H. N. Cyrus H. T. h hh D. A. Nauman M. B. Whitaker, Jr.
W. A. Willians, Jr.
O. S. Bradham R. B. Clary M. N. Browne A. R. Koon H. Radin Site Q. A.
C. L. Ligon (NSRC)
G. J. Braddidc J. L. Skolds J.
B.~ Knotts, Jr.
B. A. Bursey J. B. Cookinham I&E (Washington)
Document Management Branch
- (55e,21, LER only)
NPCF File
.... ~ _ _ _. _ - _
10CFR21 - SUBSTANFIAL SAFETY HAZARD 1.
Name and Address of Reporting Individual Stephen M. Cunningham P. O. BaK 764 Columbia, SC 29218 2.
Identification of Basic C&ponent Solid State Protection System (SSPS) (On-line test circuits) 3.
Identification of Firm Supplying Ccmponent Westinghouse Electric Corporation 4.
Nature of Defect, Substantial Safety Hazard Created, and Evaluation Periodic testing of the SSPS includes actuation of mster relays which actuate Safeguards systems. When a preselected master relay is energized, a proving lanp in series with the output (slave) relay coil confirms electrical continuity. Operation of the relay is prevented by reducing the coil voltage from 120VAC to 15VDC durirg test. The operation of the master relay by neans of the pushbutton test switch also removes tS shunt from the provirg lanp arri allows the ISVDC to energize it to confirm continuity through the output relay coil.
Upon completion of the master relay and output relay coil continuity tests,120VAC circuit voltage is restored. However, if the switch contacts which shunt the provirg lanp should fall to reclose as expected, 120VAC would be applied to the proving lanp in event the systens were called to operate.
Depending on the output relay coil inpedence and the number of output relays being operated by the master relay contacts, the current through the proving lanp could cause it to burn open before the output relays energized. In such an instance, associated Safeguards devices in the affected train would not actuate. Since, during circuit analysis, all identified nondetectable failures nust be assuned to have occurred, the redundant Safeguards actuaticn train must be assumed to have similarly, if not identically, failed.
i 5.
Date Information of Defect Was Obtained FirJust 4, 1982 f
6.
Number and Incation of Defect i
Sixteen sets of contacts are affected. 'Ihese contacts are located (eight each) in two SSPS cabinets.
7.
Corrective Action 1
'Ihe testing procedure for output relay test will be changed to incorporate steps which verify contact closure. Generic i
corrective action will be addressed by Westinghouse.
8.
Advice to Purchasers or Licensees Include steps in testing procedure to verify contact closure after performing output relay test.
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