ML20086K389

Supplement to 910925 Special Rept:On 910830,four Addl Alison Controls,Inc Detectors in Fire Detection Zone RCP-1,RCP-3, RZP-4 & Fdz A208 Failed.Caused by Dust Particles in Sensing Chamber.Subj Detectors Replaced W/Pyrotronics Model DI-6

ML20086K389
Person / Time
Site:	Davis Besse
Issue date:	12/06/1991
From:	Storz L TOLEDO EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AB-91-0034, AB-91-34, NP-40-91-03, NP-40-91-3, NUDOCS 9112130076
Download: ML20086K389 (2)

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'XO MA[h50N AdNUL TUL E DD. D' 00 4 M2 0001 NP-40-91-03 AB-91-0034 Docket Number 50-346 License Number NPF-3 December 6, 1991 United States Nuclear Regulatory Commission Document Control Desk Vashington, D. C. 20555 Subj ec t : Special Report Pursuant to Technical Specification 3.3.3.8, Fire Detection Instrumentation Gentlemen On September 25, 1991, Toledo Edison (TE) submitted a Special Report (NP-40-91-02) to the Nuclear Regulatory Commission (HRC) pursuant to Davis-Besse Nuclear Power Station Operating License, Appendix A, Technical Specification (TS) 3.3.3.8, Fire Dettetion Instrumentation, reporting the failure for greater than fourteen days of two smoke detectoss inanuf actured by Alison Cont rols, Inc.

(ACI). These two detectors vere located in the containment annulus in Fire Detection Zone (FDZ) A208. In that Special Report, TE stated that it would provide a supplemental report to the NRC following the determination by ACI of the cause of failure of the two ACI detectors. Thit Special Report also provides a new information regarding additional inoperable ACI fire detectors.

Early in Toledo Edison's seventh refueling outage, which began August 30, 1991, four additional ACI detectors in FDZ RCP-1 (Reactor Coolant Pump), FDZ RCP-3, FDZ RCP-4 and FDZ 317 (Room 317, containment hatch area) failed. Operable ACI detectors were taken from FDZ A208 and used to replace the failed detectors in order to maintain each of these other zones operable. Like the prior two failed detectors from FDZ A208, these four failed detectors were also shipped to ACI for repair. ACI determined that_four of the detectors needed a thorough cleaning to remove dust particles from the sensing chamber and two required replacement of failed transistors.

Toledo Edison had pianned to replace the ACI detectors in FDZ A208 with Pyrotronics Model DI-6 detectors during the eighth refueling outen* (tentatively scheduled for Spring 1993). Ilovever, due to these ACI detector < 41ures. TE decided to replace all of the ACI detectors in FDZ A208 with the Pyrotronics Model DI-6 detectors during the seventh refueling outage. The new detectors were installed and FDZ A208 vas declared operable on November 1, 1991, prior to the end of the seventh refueling outage.

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Docket Number 50-346 .

License Number NPF-3 NP-40-91-03 Page 2 In addition to the ACI detector failures discussed above, on October 24, 1991, the fire detection panels for FDZ 317 (containment hatch area) and FDZ 410 (containraent building east passage) vent into spurious alatm with no other indications of fire. These two zones were declared inoperabic and hourly fire watches established in accordance with the Action Statement for TF. 3.3.3.8. At that time, the plant was in Mode 5 (Cold Shutdown), preparing for plant startup.

Fire Detection Zones 317 and 410 contain twenty-six and twelve ACI detectors, '

respectively. Toledo Edison decided to replace the ACI detectors in FDZ 317 with Pyrotronics Model DI-6 detectors, and FDZ 317 was declared operable November 20, 1991. This exceeded the fourteen days allowed by TS 3.3.3.8, requiring submittal of a Special Report within thirty days (this letter satisfies that requirement).

Trnubleshooting efforts vere unable to determine the cause of the alarm in FDZ 410 and the alarm could not be reset. Several of the ACI detectors removed from FDZ 317 vere used unsuccessfully in an attempt to restore FDZ 410 to an operable status. In order not to delay plant startup from the seventh refueling outage, TE decided to defer repair / replacement of the ACI detectors in FDZ 410 until the eighth refueling outage or an outage of sufficient duration. Consequently, FDZ 410 has been maintained as inoperable and the submittal of a Special Report is required (this letter satisfies that requirement). The plant entered Mode 2 (startup) on November 2, 1991 and the hourly fire watch was terminated as

-allowed by-the Action Statement for TS 3.3.3.8 and TS Table 3.3-14, Fire Detection Instrumentation, due to the radiation levels in containment creating ,

an inaccessible condition.

On November 1, 1991, a temporary modification was implemented to jumper out FDZ 410 at its fire panel to restore the capability of other fire zones to transmit an alarm to the Control Room. Due to the high radiation levels in FDZ 410 during plant operation, this zone vill remain inoperable until the eighth refueling outage or an outage of sufficient duration. After returning FDZ 410 to an operable status, a supplemental report vill be submitted describing the actions taken.

If you have any questions, please contact Mr. R. V. Schrauder, Manager - Nuclear Licensing, at (419) 249-2366.

Very truly yours, r-j (U Louis F. Stors Plant Manager KBR/dlm cci A. B. Davis, Regional Administrator, NRC Region III J. B. Hopkins, NRC/NRR DB-1 Senior Project Manager V. Levis, NRC Region III, DB-1 Senior Resident Inspector Utility Radiological Safety Board r

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