ML20245C005
| ML20245C005 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 06/26/1987 |
| From: | Nobles L TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 87-05, 87-5, NUDOCS 8707010534 | |
| Download: ML20245C005 (3) | |
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l TENNESSEE VALLEY AUTHORITY Sequoyah Nuclear Plant Post Office Box 2000 Soddy-Daisy, Tennessee 37379 June 26, 1987 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
TENNESSEE VALLEY AUTHORITY - SEQUOYAH NUCLEAR PLANT UNIT 1 - DOCKET NO.
50-327 - FACILITY OPERATING LIC2NSE DPR SPECIAL REPORT 87-05 The enclosed special report provides details concerning the inoperability of the fire detector on the refueling floor of the Auxiliary Building in excess of 14 days. This report is submitted in accordance with Sequoyah unit 1 Technical Specifications 3.3.3.8 and 6.9.2.
Very truly yours, TENNESSEE VALLEY AUTHORITY h.
W L. M. Nobles Plant Manager Enclosure cc (Enclosure):
J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Commission Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323 Records Center Institute of Nuclear Power Operations Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 NRC Inspector, Segtoyah Nuclear Plant
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8707010534 870626}
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%-()j 1983-TVA 50m ANNIVERSARY An Equal Opportunity Employer ill j
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SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 SPECIAL REPORT 87-05 DESCRIPTION OF EVENT On May 14, 1987, with units 1 and 2 in mode 5 (0 percent power, 25 psig, 127 degrees F and 0 percent power, 250 psig, 127 degrees F, respectively),
Pyrotronic panel 0-L-615 was declared inoperable due to a shorting-out of the panel's circuitry.
Discovery of the inoperability occurred as a result of actuation of alarms and functions provided by the panel because of.the short-out. The shorting-out was caused by water.inleakage into the panel from a nearby concrete core drilling operation. Water was being used for cooling and lubrication purposes, and although provisions were made to contain the water, some did escape and subsequently shorted-out the panel.
Technical specifications (TSs) require that the panel be operable whenever any equipment that the panel protects is required to'be operable. The panel provides fire detection for several zones on the refueling floor elevation of the Auxiliary Building (elevation 734). On this elevation (734), the TS zone is the Reactor Building access room, the emergency gas
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treatment system room, and the fuel handling area. In these areas, no j
equipment specifically required for mode 5 is present; however, the auxiliary air compressors are in the fuel handling area, and they are attendant equipment for components required for mode 5.
Thus, the panel (0-L-615) must be operable.
The action of Limiting Condition for Operation (LCO) 3.3.3.8 was entered at 1515 EST on May 14, 1987, and was exited on May 30, 1987. Thus, the panel was out of service and inoperable for approximately 16 days. The action of LCO 3.3.3.8 requires submittal of a special report if the panel is i
inoperable for longer than 14 days.
CAUSE OF THE EVENT The event was caused by personnel error in inadequately protecting nearby equipment during the above described core drilling. Although provisions were made for collection and containment of the water, provisions were not made to protect the equipment in the event that all water could not be contained.
Once the panel became inoperable, Work Request (WR) B223743 was written to return the panel to operable status. A module in the panel was found to be defective due to the water inleakage and was replaced.
When the WR had been completed and the postmaintenance test performed, the panel was returned to operable status.
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ANALYSIS OF EVENT This special report is being submitted as required by the action of LCO 3.3.3.8.
The panel was inoperable for approximately 16 days. This panel is used to detect fires in key areas of the plant. When the panel was dec11. red j
inoperable, the fire header which the panel would actuate was manually charged by the plant operators to place the fire supprest. ion system in the configuration as if the detector had in fact actuated and perforined its safety function. Thus, if a fire had indeed started in an area ' protected by this panel, the mitigating effects of the fire protecticn system would not have been lessened by the panel's inoperability.
At no tlme were the health and safety of the public eve:: jeopardized due to the event.
Had the plant been in a different operating condition, the consequences of this event would have been no different.
CORRECTIVE ACTION Since the event occurred due to personnsi error in inarlequately protecting nearby equipment, the section involved (Modifications) has been counseled on the event. Modifications will issue by July 10, 1987, an internal memorandum specifically stating that nearby equipment is to be protected from inadvertent water inleakage during a core drill.
ADDITIONAL INFORMATION Three (3) previous events have occurred in which a fire protection panel has been out of service for greater than 14 days. These events resulted in Special Reports 82-03, 84-02, and 84-03.
The later of these (84-03) was due to a similar root cause (water inleakage from a core drilling, operation).
The additional corrective actions specified in this event should prevent recurrence of this event.
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