ML20100L023

Final Significant Deficiency Rept Rdc (120(84)) & Part 21 Re Class 1E Inverters Mfg by Topaz.Initially Reported on 841024.Testing of Unit 1 Inverters Will Be Completed by 850106.Unit 2 Completion Consistent W/Const Schedule

ML20100L023
Person / Time
Site:	Perry
Issue date:	11/28/1984
From:	Edelman M CLEVELAND ELECTRIC ILLUMINATING CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
REF-PT21-84, REF-PT21-85-031-000 PT21-85-031-000, PT21-85-31, RDC-(120(84)), NUDOCS 8412110405
Download: ML20100L023 (2)

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a <) f'A THE CLEVELA!!D ELECTRIC ILLUiMIN ATING COMPANY P.O. box 5000 - CLEVELAND ohio 44101 - TELEPHONE (216) 622-9800 - lLLUMINATING BLDG. - 55 PUBLICSQUARE Serving The Best Location in the Nation MURRAY R. EDELMAN VICE PRESIDENT NUCLEAR Mr. James G. Keppler Regional Administrator, Region III Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 RE: Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Topaz Class IE Inverters RDC [120(84)]

Dear Mr. Keppler:

This letter serves as a final report on the potential significant deficiency concerning Class IE inverters manufactured by Topaz which are utilized in various control panels supplied by General Electric. This item was originally identified to Mr. Knop of your office on October 29, 1984, by Mr. P. P. Martin of The Cleveland Electric Illuminating Company (CEI). General Electric reported this deficiency to the NRC in accordance with 10CFR21 on October 6, 1984.

This report contains a description of the deficiency, an analysis of safety implications, and the planned corrective action.

Description of the Deficiency General Electric (GE) notified CEI in a letter dated October 11, 1984, that the adjustment of the low voltage shutoff and turnon for GE dedicated Class IE inverters was set too high. The original manufacturer, Power Mark, ardivision of Topaz, set the adjustment too high. In the GE dedication process, an operable range of 105 to 140 volts DC was being checked for instead of the required range of 100 to 140 volts. Typical DC bus voltages range from 108 to 132 volts with momentary voltage dips to 105 volts DC during the startup of large DC loads. This results in a condition where the inverter'may not start or restart until the voltage is increased to 118 volts DC since there is a 13 volt fixed offset above 105 volts.

Analysis of Safety Implications Because the allowable momentary dip of the input bus voltage for the inverters is equal to the preset inverter low voltage cutoff, 105 volts, an allowable voltage dip could result in an inverter trip and a failure to restart during a design basis accident. The subject inverters are used to power 24 volt DC 04121 405 041120 PDR A CK 05000440 PDR DEC 3 1984 h$[+

a. o Mr. Jtmes G. K:ppist 'Naviabar 28, 1984 instrument buses in the Reactor Core Isolation Cooling (RCIC) and various Emergency Core Cooling Systems-(ECCS). Failure of the-inverters during a design basis accident could result in a loss of the RCIC or ECCS functional capability to perform their intended safety function.

Corrective Action

'Nonconformance Report (NR) NDS-0098 was issued by Project Organization to track-the Topaz inverters. GE is issuing Field Disposition Instructions (FDI) WOBO and WOBW to provide for testing of the inverter trip and restart voltages and adjust the settings as necessary for Unit 1. Unit 2 will be covered in the same manner by FDI's WRXD and WRIJ. All affected inverters will be adjusted so they will not trip at voltages between 100 and 140 volts DC and will resume operation when.the input voltage increases to 108 volts DC. It is anticipated

! that the testing and adjustment of _all Unit 1 and spare inverters will be completed by January 6, 1985. Testing and adjustment of the Unit 2 inverters l will be completed consistent.with the Unit 2 construction schedule and prior to turnover of the affected systems.

Please call if there are any additional questions.

! Sincerely,

'} /  %

Murr'y R. Edelman Vice President Nuclear Group MRE:pab cc: Mr. J. A. Grobe USNRC, Site Office Mr. D. E. Keating USNRC, Site Office Records Center, SEE-IN Institute of Nuclear Power Operations 1100 circle 75 Parkway, Su'ite 1500 Atlanta, Georgia 30339 Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 U.S. Nuclear Regulatory Commission c/o Document Management Branch a Washington, D.C. 20555 s