ML20154J435
| ML20154J435 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/16/1988 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8805260371 | |
| Download: ML20154J435 (5) | |
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. 4 TENNESSEE VALLEY AUTHORITY CH ATTANOOG A. TENNESSEE 37401 SN 1578 Lookout Place YAY 161988 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Hashington, D.C.
20555 Gentlemen:
In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-323 SEQUOYAH NUCLEAR PLANT (SQN) - NRC INSPECTION REPORT NOS. 50-327/88-22 AND 50-328/88 RESPONSE TO UNRESOLVED ITEM (URI) 50-327, -328/88-22-01 Enclosed is my response to F. R. McCoy's letter to S. A. White dated April 13, 1988, that transmitted Inspection Report Nos. 50-327/88-22 and 50-328/88-22 and requested response to URI 50-327, -328/88-22-01.
If you have any questions, please telephone M. R. Harding at (615) 870-6422.
Very truly yours, TENNESSEE VALLEY AUTHORITY l
R. Gridley, D ctor Nuclear Licensing and Regulatory Affairs Enclosures cc: See Page 2 l
b 8805260371 880516
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An Equal Opportunity Ernployer
' U.S. Nuclear Regulatory Commission g g g jggg cc (Enclosures):
Mr. K. P. Barr, Actirig Assistant Director for Inspection Programs TVA Projects Division U.S. Nuclear Regulatory Commission Region II 101 Marietta Street NW, Suite 2900 Atlanta, Georgia 30323 Mr. G. G. Zech, Assistant Director for Projects TVA Projects Division U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379
't ENCLOSURE 1 URI 50-327, -328/88-22-01 "On March 28, 1988, at 9:15 p.m., the inspectors reviewed the work associated with the repairs performed on 2-LCV-3-173.
This is the control valve on the AFH header which is supplied from the TDAFP and is utilized to feed and maintain the water level in the #2 SG, The inspectors noted that the manual block valve, 2-HCV-3-868, upstream of the LCV, was unlocked and closed. An immediate review of the status of this equipment with the on-shift Assistant SS revealed that the work on valve 2-LCV-3-173 had been completed and the valve had been declared operable at 5:37 p.m. on March 28, 1988 and LC0 3.7.1.2, was exited.
The LC0 for this LCV repair had been entered on
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March 27 at 8:09 p.m. per the LC0 log.
With the manual block valve in the closed position, the safety system could not feed the #2 SG from the TDAFP in the event of an accident condition.
Additional review of the LCO log indicated that the same LCO, 3.7.1.2, had been entered on March 28, 1988 at 2:08 p.m. for repair to the control / alarm instrumentation associated with the feedwater supply to the TDAFP.
Therafore, LCO 3.7.1.2 was in effect during the timeframe that the manual valve was closed although it was not apparent to the operator that any off-normal conditions remained from the repairs to the LCV. A review of the Configuration Log revealed that the closed valve configuration had been entered.
This log is required by AI-5 to be reviewed by the on-coming R0 and the Assistant SS.
However, the turnover between the day-shift and evening-shift on March 28, 1988 did not identify in Appendix Al of AI-5 any off-normal or unusual condition associated with having 2-HCV-3-868 in the closed position.
The turnover on the previous shift had identified that valve 2-HCV-3-868 was in the closed position. Additionally, the inspector did not identify any reference to the closure of 2-HCV-3-868 during a review of the Unit 2 R0 log between March 27, 1988, when the LCV failed its SI, through 9:30 p.m. on March 28, 1988, when the inspectors notified the control room personnel of the problem.
When notified, operations personnel took immediate action and had the valve opened and verified locked open.
This will be considered an unresolved item pending licensee investigation and l
further NRC review (327,328/88-22-01)."
Root Cause j
At 8:09 p.m. EST on March 27, 1988, 2-LCV-3-173, the steam generator level i
control valve from the turbine-driven auxiliary feedwater pump (TDAFWP) to 3
steam generator No. 2, was declared inoperable because of a defective I
asitioner; and limiting condition for operation (LCO) 3.7.1.2 was entered.
At 2:18 a.m. EST on March 28, 1988, the assistant shift supervisor (SS) on unit 2 approved work on 2-LCV-3-173 through work request (HR) B267624. At 3:00 a.m. EST, the assistant SS completed an appendix 8 configuration file sheet detailing the closure of 2-HCV-3-868 (the manual isolation valve for 2-LCV-3-173) in accordance with Administrative Instruction (AI) 58, "Maintaining Cognizance of Operational Status - Configuration Status Control, Units 0, 1, and 2," to protect plant equipment and personnel during the maintenance work.
The configuration sheet was filed in the daily configuration log. A note was also added to the impact evaluation sheet used by the work control grouo indicating the closure of 2-HCV-3-868. Maintenance i
j work continued through the rest of the shift; so,during shift turnover, the
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. midnight shift recorded the closure of 2-HCV-3-868 in their AI-5, "Transfer of Authority and Responsibility," sheet to inform the oncoming day shift of the activity. At 2:08 p.m. EST, LC0 3.7.1.2 was entered for pressure switch problems on the TDAFHP (WR 8267969). At 5:37 p.m. EST, the instrument mechanics notified the unit 2 assistant SS that 2-LCV-3-173 could be returned to service.
The assistant SS reviewed Surveillance Instruction (SI) 166.6, "Testing of Category 'A' and 'B' Valves After Haintenance or Upon Release From a Hold Order - Units 1 and 2"; declared the valve operable; and exited LCO 3.7.1.2 for 2-LCV-3-173 only. At 9:30 p.m. EST, NRC inspectors approached-the unit 2 assistant SS about the operability of 2-LCV-3-173.
The inspectors asked if the assistant SS was aware that 2-HCV-3-868 was closed.
The assistant SS indicated he was not aware that the valve was closed.
The root cause of this event was inadequate information recorded in AI-6, "Log Entries and Review," regarding off-normal equipment associated with an entry into an LCO.
Corrective Action As immediate corrective action, the assistant SS instructed the unit operator to have valve 2-HCV-3-868 opened. At 9:45 p.m. EST, the valve was Independently verified to be locked open.
SI-186, "Locked Valve Position Verification (Per NRC Commitment) Units 0,1, and 2," was also p?rformed on the valve at that time.
The AI-58 configuration log was signed off indicating the valve had been returned to the normal position.
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As long-term corrective action, SQN is revising AI-6 to provide additional 1
space in the LC0 action 1.g and is requiring that the reason (s) for entering the LC0 and specific actions / equipment conditions be entered in the log as appropriate.
In addition, a verification will be added to the LCO log to ensure operators align systems for technical specification operability.
This will be accomplished by an appropriate review of the configuration log.
This revision will be completed by August 19, 1988.
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-t ENCLOSURE 2 J
List of Cominitments 1.
Revise AI-6 to provide additional space in the LCO action log and require the reason (s) for entering LC0 and specific actions / equipment conditions be entered in the log as appropriate.
In addition, a verification will be added to the LCO log to ensure operators align systems for technical specification operability.
This will be accomplished by an appropriate review of the configuration log.
This revision will be completed by
-August 19, 1988.
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