ML20236B743
| ML20236B743 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/22/1987 |
| From: | Nobles L TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 87-06, 87-6, NUDOCS 8707290219 | |
| Download: ML20236B743 (3) | |
Text
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TENNESSEE VALLEY AUTHORITY
[
Sequoyah Nuclear Plant Post Office Box 2000 l
Soddy-Daisy, Tennessee 37379 July 22, 1987 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
TENNESSEE VALLEY AUTHORITY - SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 - DOCKET NOS. 50-327 AND 50-328 - FACILITY OPERATING LICENSE DPR-77 AND SPECIAL REPORT 87-06 The enclosed special report provides details concerning the inoperability of photoelectric fire detectors in various air handling units in excess of 14 days. This event is reported in accordance with Sequoyah Nuclear Plant's units 1 and 2 Technical Specifications 3.3.3.8 and 6.9.2.
Very truly yours, TENNESSEE VALLEY AUTHORITY l
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, Sequoyah Nuclear Plant 8707290219 870722 PDR ADOCK 05000327 PDR g
l 1983-TVA SOTH ANNIVERSARY An Equal Opportunity Employer j
SEQUOYAff NUCLEAR PLANT l
UNITS 1 AND 2 1
SPECIAL REPORT 87-06 DESCRIPTION OF EVENT On June 8, 1987, with units 1 and 2 in mode 5 (0 percent power, 4 psig, 131 degrees F and 0 percent power, 240 psig, 13C degrees F, respectively),
Pyrotronics Model No. DA-1 photoelectric detectors in various air handling units were declared inoperable due to discovery that these detectors were not Underwriters Laboratories (UL) listed for this application. This detector was significantly less sensitive than other existing technology.
Hence, this detector was never UL tested. The plant is committed to National Fire Protection Association (NFPA) 72D which requires the detectors to be listed for the protective signaling purpose for which the detectors are used. 'This was discovered during a review of drawings by TVA's Division of Nuclear Construction and was documented in Condition Adverse to Quality Report SQP870401.
Technical specifications require that the detectors be operable whenever any equipment protected by the fire detection instrument is required to be operable. The systems / components affected by these detectors are containment purge, emergency gas treatment filters, lower compartment coolers, upper compartment coolers, and auxiliary building gas treatment system filters.
The action of Limiting Condition for Operation (LCO) 3.3.3.8 was entered at 1329 EST on June 8, 1987, and will continue uritil the detectors are replaced.
CAUSE OF EVENT This event was caused by a design deficiency. The photoelectric type of detector originally specified and used was not listed for this particular application. TVA had previously committed to NFPA 72D which requires the detectors to be listed. The subject detectors were declared inoperable when it was determined that the detectors were not qualified for duct applications.
ANALYSIS OF EVENT This special report is being submitted as, squired by the action statement l
of LCO 3.3.3.8.
The action required by LCO 3.3.3.8 has been initiated to compensate for the l
decreased sensitivity of these detectors.
Had a fire occurred while this condition existed, the subject non-qualified detectors would have detected a fire. However, they are not as sensitive as other detectors used in this application. Also, there are other means of suppression in these areas such as fire hoses and sprinkler systems which would have prevented excessive plant damage. The effects of this event would not have changed had this occurred while in a different operating condition since a fire watch would have been established in accordance with Technical Specification requirements. The health and safety of the public is not affected by this event.
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'l CORRECTIVE ACTION
.The present plan for restoring the instruments to operable' status is.to replace the current units,with Pyrotronics Model PEC-3 with AD-3P housing duct detector units..This model detector.-is also a photoelectric detector, 1
but this detector is UL listed for this application..
TVA has'taken action toTconsolidatelall.of the. engineering. functions.that Lare accomplished within'the Division'of. Nuclear Engineering. This includes providing direction-for accountability in ensuring adequate design controls exist. These actions will serve as recurrence control for this event j
ADDITIONAL INFORMATION
.There have been four' previous,special reports written on fire detectors-being inoperable longer'than fourteen days 'SR 80-05, 82-03, 84-03, and' 87-05.
This-is the first report-written on fire detectors which was the result of; a design deficiency.
0566Q 1
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