ML20028G083
| ML20028G083 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 02/01/1983 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| Shared Package | |
| ML20028G084 | List: |
| References | |
| NUDOCS 8302070381 | |
| Download: ML20028G083 (4) | |
Text
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1 SOUTH CAROLINA ELECTRIC & gas COMPANY PO.T OFFICE 764 COLuualA, south CAROLINA 29218 ,
u o, W. DixON, JR. 9 uve$*,'d"o',*,',h"[ .. February 1,1983 3 ;
us s
Mr. James P. O'Reilly, Director Ei U.S. Nuclear Regulatory Commission
- Region II, Suite 3100 ca 101 Marietta Street, N.W.
Atlanta, Georgia 30303
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SUBJECT:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Fourteen Day Written Report LER 83-001
Dear Mr. O'Reilly:
Please find attached Licensee Event Report #83-001 for the Virgil C. Summer Nuclear Station. This Fourteen Day Report is required by Technical Specification 6.9.1.12.(b) as a result of failure to i comply with Action Statement 19 of Technical Specification 3.3.2, Table 3.3-3, Item 8, " Engineered Safety Feature Actuation System Isistrumentation," and entry into Action Statements (a) and (b) of Technical Specification 3.3.3.6, " Accident Monitoring Instrumentation," on January 19, 1983.
Should there be any questions, please call us at your convenience.
Very truly yours, O. W. Dixon, Jr.
O.Y CJM:OWD:dwf/fjc Attachment cc: V. C. Summer A. R. Koon T. C. Nichols, Jr. G. D. Moffatt E. C. Roberts Site QA O. W. Dixon, Jr. C. L. Ligon (NSRC)
H. N. Cyrus G. J. Braddick H. T. Babb J. L. Skolds D. A. Nauman J. B. Knotts, Jr.
M. B. Whitaker, Jr. B. A. Bursey W. A. Williams, Jr. I&E (Washington)
O. S. Bradham Document Management Branch R. B. Clary INPO Records Center M. N. Browne NPCF File g(f',
,5 0'Y 8302070381 830201 PDR ADOCK 05000395 -
S PDR f, f d b
Mr. - James P. O'Reilly LER No.83-001 Page Two February 1, 1983 .
DETAILED DESCRIPTION OF EVENT On January 19, 1983, at 0630 hours0.00729 days <br />0.175 hours <br />0.00104 weeks <br />2.39715e-4 months <br /> with the Plant in Mode 1, Refueling Water Storage Tank (RWST) level instrument (LI-990) failed high. This is a. Post Accident Monitoring System (PAMS)
Instrument, and Technical Specification 3.3.3.6, Action Statement (a) was entered. At 0835 hours0.00966 days <br />0.232 hours <br />0.00138 weeks <br />3.177175e-4 months <br />, a second RWST level instrument (LI-991), which is not a PAMS instrument, failed high. At 0915 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.481575e-4 months <br />, a third RWST level instrument (LI-992), which is a PAMS instrument failed high, and Technical Specification 3.3.3.6, Action Statement (b) was entered. At this point, there was only one (1) operable RWST level instrument (LI-993). LI-990 was returned to operable status at 1010 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.84305e-4 months <br />.
At 1015 hours0.0117 days <br />0.282 hours <br />0.00168 weeks <br />3.862075e-4 months <br />, it was realized that Technical Specification 3.3.2, Table 3.3-3, Item 8, was applicable and required the operability of four (4) RWST level instruments. Action Statement 19 had not been complied with, and Technical Specification 3.0.3 was implemented. The start time for the implementation of Technical Specification 3.0.3 was established at 0835 hours0.00966 days <br />0.232 hours <br />0.00138 weeks <br />3.177175e-4 months <br />. Unless three (3) RWST level instruments were returned to operable status by 1535 hours0.0178 days <br />0.426 hours <br />0.00254 weeks <br />5.840675e-4 months <br />, the Plant would have to be in Hot Standby.
At 1115 hours0.0129 days <br />0.31 hours <br />0.00184 weeks <br />4.242575e-4 months <br />, action was taken to place the bistables associated with RWST level instrument (LI-992) in the tripped condition. The bistables associated with LI-991 were not placed in the tripped condition at this time since Operations personnel considered this action would have placed the Plant in an unsafe condition. With the two-out-of-four logic for Lo-Lo RWST level "made up", any Safety Injection signal would create a flow path from the RWST directly to the Reactor Building Recirculation sumps.
At 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />, a Turbine Load Reduction was initiated at the predetermined rate of 1% per minute in order to comply with Technical Specification 3.0.3. At 1304 hours0.0151 days <br />0.362 hours <br />0.00216 weeks <br />4.96172e-4 months <br />, RWST level inst rument (LI-992) was returned to operable status, and the Turbine Load Reduction was stopped since three (3) RWST level instruments were operable. RWST level instrument (LI-991) was subsequently placed in the tripped condition at 1308 hours0.0151 days <br />0.363 hours <br />0.00216 weeks <br />4.97694e-4 months <br />.
On January 20, 1983, at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br />, it was discovered that RWST level instruments (LI-991) and (LI-992) had actually been placed in bypass instead of the intended trip condition as identified in Action Statement 19 of Technical Specification 3.3.2. Channel LI-991, which was presently out of service, was placed in the tripped condition at the time of this discovery.
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l Mr. James P. O'Reilly LEE No.83-001 Page Three February 1, 1983 l
l DETAILMD DESCRIPTION OF EVENT (Continued) l Repairs were completed on RWST level transmitter (LT-991) on January 21, 1983. The channel was returned to operable status at 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br /> upon the satisfactory performance of a transmitter calibration with the appropriate surveillance test procedure.
PROBABLE CONSEQUENCES There were no adverse consequences during the event; however, for approximately fifty five (55) minutes, the failure of three (3)
RWST level channels in the high direction would have prevented the automatic transfer of suction for the Residual lleat Removal (RHR) and Reactor Building Spray pumps from the RWST to the Reactor Building Recirculation sumps in the event of a Lo-Lo RWST level coincident with a Safety Injection signal. Emergency Operating Procedure EOP-1, " Safety Injection," contains procedural steps to instruct the operators to manually perform the transfer of suction for the RHR and Reactor Building Spray pumps in the event automatic transfer does not occur.
CAUSE(S) OF THE OCCURRENCE The f ailure of the RWST level instrumentation was due to the frozen insrument lines at the base of the transmitter. The level transmitters were not adequately heat traced at time of the occurrence.
IMMEDIATE CORRECTIVE ACTIONS TAKEN Maintenance personnel were directed to investigate the possible failure of the heat tracing on RWST level transmitter (LT-990) immediately after the 0630 occurrence. The heat tracing on the instrument lines was found to be operational and maintaining temperature at approximately 50 F; however, the level transmitter was found to be open to the environment and not heat traced. Heat was applied to the transmitter at that time since it appeared that the failure of LT-990 was due to f rozen instrument lines at the base of the transmitter. The transmitter was returned to operable status at 1010 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.84305e-4 months <br /> as verified by a channel check.
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- Mr. Janes P. O'Reilly LER No.~83-001 Page Four February 1, 1983 IMMEDIATE CORRECTIVE ACTIONS TAKEN (Continued)
Maintenance personnel were notified during the repair of LT-990 that similar f ailures had occurred on LT-991 at 0835 hours0.00966 days <br />0.232 hours <br />0.00138 weeks <br />3.177175e-4 months <br /> and LT-992 at 0915 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.481575e-4 months <br />. Investigation into the cause of failure again indicated that the transmitter instrument lines were f rozen at the base of the transmitter. RWST level transmitter (LT-992) ,
was thawed and returned to 6perable status at 1304 hours0.0151 days <br />0.362 hours <br />0.00216 weeks <br />4.96172e-4 months <br /> af ter the performance of a satisfactory channel check. Attempts to restore LT-991 to operable status were not successful on the morning of January 19, 1983, due to internal damage of the transmitter. The transmitter was replaced and returned to operable status at 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br /> on January 20, 1983,:upon the completion of a satisfactory calibration with the appropriate surveillance test procedure.
In addition to the above repair actions, maintenance personnel installed additional heat tracing on the transmitters. The additional heat tracing was a temporary means to prevent recurrence until an engineering evaluation of the system design could be accomplished.
ACTION TAKEN TO PREVENT RECURRENCE The Licensee is performing the following actions to prevent recurrence:
- 1. The heat tracing sensors have been determined to be in the correct location on-the RWST level instrument lines.
Action is being taken to install insulated enclosures and additional permanent heat tracing on the RWST level transmitters. This action is expected to be complete by February 15, 1983. Temporary measures will remain in effect until this modification is complete.
- 2. In regards to the generic issue of freeze protection for plant instrumentation, we are investigating all other similar situations (i.e., Condensate Storage Tank).
Additional corrective actions as necessary will be taken.
- 3. Operations personnel will be instructed to review the Surveillance Test Master (GTP-701) during future events to provide additional assurance that Technical Specifications associated with f ailed instrumentation will be recognized.
This action will be accomplished by February 28, 1983.
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