ML20040F536

Final Deficiency Rept 82-01 Re Diesel Generator Air Start Motor Defects,Originally Reported on 820109.Motors Will Be Rebuilt & Installed on Diesel Generators If New Motors Are Not Received Prior to Fuel Load

ML20040F536
Person / Time
Site:	LaSalle
Issue date:	01/27/1982
From:	Sargent C COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8202090317
Download: ML20040F536 (2)

Text

_ _________________ _ __ _ ____ _________________

!' Commonwealth Edison

) one Fwst N tional PI:za. Chicito, lilinois

• (C 7 Address Reply to: Post Offics Box 767 j / Chicago. Illinois 60690 January 27, 1982 O A b}  ?.2  %

Mr. James G. Keppler, Regional Administrator Directorate of Inspection and ;J N kU 'O d9 Enforcement - Region III -\

f4%)E /d /s U.S. Nuclear Regulatory Commission 799 Roosevelt Road {h,3% V-e ,'h* *3 4 Glen Ellyn, IL 60137 -

< 77 7

Subject:

LaSalle County Station Units 1 and 2 Diesel Generator Air Start Motor Defects 10 CFR 50.55(e) Final Report #82-01 NRC Docket Nos. 50-373 and 50-374

Dear Mr. Keppler:

The Commonwealth Edison Company notified Mr. Roger Walker of your office on January 9, 1982, of a possible manufacturing defect in new air start motors used on the Electromotive Diesel Generators at LaSalle County Station. That notification was made in accordance with 10 CFR 50.55(e). This letter fulfills the 30 day reporting requirement of that regulation.

Description o f De ficiency During a telecon on January 7, 1982, the District Engineer for Electromotive notified the System Test Engineer that new air start motors (EMD Part No. 8367694) purchased by LaSalle were potentially defective. The defect is due to a change in the pinion gear housing inlet and outlet port spacing in Feb., 1981, by Ingersoll-Rand causing a higher pressure drop across the outlet port. The higher pressure drop means the control air pressure for opening the Air Start Valve is lower, possibly failing to open the Air Start Valve, thus preventing the diesel from starting.

The change in port spacing and the higher pressure drop across the ports was first observed at LaSalle during troubleshooting to determine why the new air s tart motors f ailed to s tart HPCS Diesel Generator 18, IE22-S001, on Octobe r 14, 1981. The Elec-tramotive (EMD) District Engineer was notified o f the problem on October 16, 1981, by the LaSalle Maintenance Department. The District Engineer stated that the pressure drop was not excessive based on the air pressure needed to open the Air Start valves. At his direction, the motors were replaced with four other new motors, which started the diesel with no problems observed. Based on operability of the second set of motors, the District Engineer stated that the failure o f the first set of motors would be investigated, but did not appear to be due to the port spacing. His investigation included checking for other 8202090317 820127 I

{DRADOCK 05000373 ff.B S I @ __ ._;

J. G. Keppler January 27, 1982 reported air start motor problems and contacting Ingersoll-Rand concerning the problem. Per a telecon, Electromotive found no other-reported failures and neither did Ingersoll-Rand until the week o f November 23, 1981, when 1-R received reports on some starter failures on some buses which use the same pinion gear housing. This led to the determination by 1-R that the port spacing was the cause. The District Engineer received the information on the defect the week of December 28, 1981.

Analysis of Safety Implications Based on start f ailures during starts on stored air tests of Standby Diesel Generator 2A, 2DG0lK , in Decembe r,1981, it appears that a diesel start failure may occur at lower than normal stored air pressure due to the air start motor defect.

No other start failures have been noted by LaSalle, except for a start of Diesel Generator 18, lE22-S0001, which had a start that was delayed about 6 seconds during a start on stored air. The subsequent start was acceptable at a lower air pressure.

Corrective Action and Corrective Action to Prevent Recurrence The defective air start motors, currently installed on Diesel Generator 0, ODG01K; 1A, 10G0lK; 2A, 2DG0lK; and IB, lE22-S001, as well as the four air start motors on Q. A. hold since October 19, 1981, will be replaced by Electromotive with new air start motors built to the original dimensions for the inlet and outlet port spacing. No date is available for when the parts will become available. If new motors cannot be obtained prior to fuel load, the original motors (those on the diesels prior to the defective air start motors) will be rebuilt and installed on the diesel generators and the new, corrected air start motors will be kept as spares when they are received. Electromotive will supply dimensional specifications which will be used during Q.C. receiving inspection to verify proper port spacing on all future air start moto:s. Acceptable air start motors, either new or rebuilt, will be installed prior to fuel load.

Please address any further questions concerning-this matter-to this office.

Very truly yours, e eld C. E. Sargent Nuclear Licensing Administrator cc: Director o f Insp. & Enf. - Washington, D.C.

Region III Inspector - LSCS 1m 3330N