ML20084U050
| ML20084U050 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/21/1991 |
| From: | Shelton D CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 1899, NUDOCS 9103290189 | |
| Download: ML20084U050 (2) | |
Text
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CENTERIOR ENERGY Donald C. Shelton 300 Madison Avenue Vce Presdent Nuclear Toledo, OH 43%20001 Dangesse 1419)249 2300 Docket Number 50-346 License Number NPF-3 Serial Number 1899 March 21, 1991 United States Nuclear Regulatory Commission Decument Control Desk Vashington, D. C.
20555
Subject:
Fire Protection - Essential Inverter Replacement Schedule Change Gentlemen:
In Toledo Edison (TE) letter Serial Number 1757 dated February 16, 1990, TE committed to install four new essential 125 VDC inverters based on a 10 CFR Part 50, Appendix R, Fire Protection analysis which concluded that the existing four essential inverters (YVI, YV2, YV3, YV4) were not coordinated (i.e., a single fault could result in the inverter being lou due to input fuse failure). The coordination concern was eliminated during the sixth
-refueling outage by installing two nov inverters, modifying the remaining two inverters and instituting additional operator actions.
The remaining two new inverters were scheduled to be installed during the seventh refueling outage.
TE's intent to install the remaining two inverters during the seventh refueling outage is also reflected in Nuclear Regulatory Comr ssion (NRC)
Inspection Report 89-19, dated September 29, 1989, documenting closure of 1.icensee Event Report 84-010, and in Inspection Report 90-002, dated March 30, 1990, documenting closure of Licensee Event Report 87-013.
TE has determined that installation of the remaining two inverters during
'he seventh refueling outage is no longer necessary.
In addition to the changes and modifications performed during the sixth refueling outage, several plant improvements have been implemented since 1985 which diminish the need for such replacement. These improvements include modifications to the integrated control system and'non-nuclear instrumentation system to prevent a plant trip on loss of the old inverters, additi(n of manual trensfer capabilities to an alternate po.ier source for the old inverters, and improved plant maintenance practices which should limit tue occurrence o
of pcVer losses to the old inverters.
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Docket Numb 2r 50-346 i
License Number NPF-3
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As indicated above, the present configuration (two old and two new inverters), combined with manual operator actions described in the Fire llazards Analysis Report (Revision 12), fully complies with the applicable requirements of 10 CFR 50, Appendix R.
Therefore, TE does not intend to o
install the remaining two new inverters.
If you have any questions, please contact Mr. R. V.
Schrauder, Manager -
Nucleat Licensing, at (419) 249-2366.
Very truly yours, O
gfx (f'N KBR/mmb cc:
P. M. Byron, DB-1 NRC Senior Resident Inspector A. B. Davis, Regional Administrator, NRC Region III J. R. Elall, NRC Senior Project Manager q
H. D. Lynch, NRC Senior Project Manager Utility Radiological Safety Board W
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