ML20040C936
| ML20040C936 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 01/18/1982 |
| From: | Yundt C PORTLAND GENERAL ELECTRIC CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| CPY-048-82, CPY-48-82, NUDOCS 8201290388 | |
| Download: ML20040C936 (1) | |
Text
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50'3 Portland General Electric Company m.. E 2! F li: 27 Trojan Nuclear Plant P.O. Box 439 Rainier, Oregon 97048 January 18, 1982 (503) 556-3713 ilEi d
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Mr. R. H. Engelken, Director US Nuclear Regulatory Commission O
Region V - Suite 210 j?p gE/Pp,g' f
1450 Maria Lane 9 [4Ng Walnut Creek, CA 94596-5368
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Immediate Report of Reportable Occurrence
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Dear Sir:
This letter is a followup to a report made by Mr. R. P. Barkhurst, Manager of Operations and Maintenance, to Mr. M. H. !'almros, NRC Resident Inspector, at 8:00 AM, Monday, January 18, 1982, concern Wg c situation where the plant was operated with less than the minimum A.C. electrical power sources as requited by Technical Specification 3.8.1.1.
This repart is being made in accordance with Technical Specification 6.9.1.8.b.
In May,1977, it was determined that the Emergency Diesel Generators (EDGs) can be effectively disabled when the 120 VAC Preferred Instrument Bus supplying the associated train of solid-state reactor protection is powered from its alternate source. These buses are normally powered from a static inverter which uses either 120 VAC or 125 VDC input. However, if the inverter is out-of-service, the bus can be powered directly from a non-preferred bus.
As a result of the investigation con 3ucted in 1977, a Training Information Bulletin (TIB) was generated advising the operators of this potential problem.
However, the TIB mistakenly listed bus Y22 as the one affecting the East ~
EDG operation instead of bus Y24. This mistake was discovered as a result of this weekend's failure of the inverter which supplies Y22.
A subsequent review of plant records reveals that the East EDG was effectively out-of-service due to this problem from 1110 on 12-1-81 until 1345 on 1-4-82.
This occurrence will be reported to the Nuclear Regulatory Commission as a Licensee Event Report in accordance with our established Technical Specifications.
Sincerely, p7
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A't C.
undt
//Q General Manager CPY/MLD:bb c: LER Distribution List 8201290388 820118 PDR ADOCK 05000344 S