ML20064G714

Interim Rept of Significant Deficiency 9 Defective Emergency Diesel Generator Roller Pin Describing Abnormal Wear on Surface of Roller Pin Valve Crosshead in Some Pwr Cylinder Subassemblies

ML20064G714
Person / Time
Site:	Waterford
Issue date:	12/05/1978
From:	LOUISIANA POWER & LIGHT CO.
To:
References
NUDOCS 7812130152
Download: ML20064G714 (4)

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LOUISIANA POWER & LIGilT COMPANY WATERFORD SES UNIT NO. 3 N

/1 47 Y D

.'O g)3 INTERIM REPORT OF SIGNIFICANI DEFICIENCY NO. 9 DEFECTIVE EMERGENCY DIESEL GENERATOR ROLLER PIN t

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INTERIM REPORT SIGNIFICANT DEFICIENCY REPORT NO. 9 DEFCCTIVE EMERCENCY DIESEL GENERATOR ROLLER PIN INTRODUCTION This report is submitted pursuant to 10CFR50.55(e) (3). It describes a deficiency in the emergency diesel generators supplied by Cooper Energy Services for Louisiana Power & Light Company's Waterford Steam Electric l Station Unit No. 3 and others. l DESCRIPTION On November 3, 1978, Cooper Energy Services purstant to 10CFR21 notified the USNRC-Office of Inspection and Enforcement, Washington D.C. of a defective roller pin in the crosshead subassembly of each power cylinder within a KSV Power Engine.

The extent of the deficiency is as follows: Each power cylinder has one inlet and one exhaust push rod assembly and two valve crosshead assemblies.

The valve crosshead assembly contains a crosshead, a roller pin, and a pin collar. During a recent performance test on this engine at another facility it was found that some subassemblics showed abnormal wear on the surface of the roller pin. No engine shutdown nor malfunction was experienced, but it is felt by the manufacturer that over a longer period of engine operation this abnormal wear could progress far enough to cause the engine to malfunc-tion. This defect is considered to be reportable and is described in Attachment A (Cooper Energy Service letter to NRC dated November 3, 1978).

SAFETY IMPLICATIONS This deficiency, if left uncorrected, could possibly cause an' engine malfunc-l tion. There would be no significant safety implication of engine malfunction during normal plant operation. '.lowever, this deficiency could invalidate some of the assumptions used in the safety analysis report. If a design basis accident

(e.g. LOCA or main steam line break) were to occur coincident with a loss of l

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offsite power, and the diesel-generators did not perform in accordance with specifications, then some essential equipment used to mitigate the conse-quences of the postulated accident could be degraded.

CORRECTIVE ACTION The corrective action to be taken by Cooper Energy Service is to redesign to increase the diameter of the roller pin to provide an interference fit at the assembly between the roller pin and the crosshead and reduce the clearance between the roller pin and the collar. In addition the hand flaring operation to seat the pin ends into chamfer on the crosshead has been replaced by a more consistent and positive press operation.

Cooper Energy Services will replace the inlet and exhaust valve crosshead assemblics with those of the new design by August 31, 1979.

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- Attachment A - pg 1 of 2

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, (C ." CODPE3-CESSEMER C0f.il'/GiY l ESTh flovember 3, 1978 Of'fice of Inspection and Enforcement U. S. Iluclear Regulatory Commi.ssion Washington, D. C. 20555

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ATTil: Director of Inspection and Enforcement.

Gentlemen:

In .accordance with 10CFP. Part 21, this letter is notification of a deficiency found 9'-13-78 within a KSV Po.icr Engine supplied and manufcctured by Cooper Energy Services. This engine is part of the emergency standby diesel-gencrator set supplied'for installation at (4) four licensees' stations.

The extent of the deficiency is as follows: Each power cylinder has (1) inlet and (1) exhaust push rod assembly and (2) valve crosshead assemblics Part ilo. Z25-1-2#10. This sub-assembly contains; a crosshead Part ilo. JS-25-lG, a roller pin Part' li o . JS-25-lP, and a pin collar Part f;a. JS-25-1:4. During a recent performance test on this engine, it was found that some sub-assemblies showed abnormal wear on the surface of the roller pin. lio engine shutdown nor mal-function has been experienced, but it is felt that over a longer period of. engine operation this i abnormal wear could progress far'enough to cause the engine to mal-function.

The corrective action taken by C.E.S. is to redesign to increase

, the diameter of the roller pin (JS-25-lP) to provice an inter-forence fit at assembly between the roller pin and the crosshead (JS-25-lG) and reduce the clearance between the roller pin and the collar (JS-25.lli). In addition the hand flaring operation to seat the pin ends into chamfer on the crosshead has been - i

replaced by a more consistent and positive press operation. The i sub-assemblies in field units named below are to be inspected and replaced if required. The time' span for the execution of tht change out by C.E.S. on field units will be dependent upon avail-

ability of units for rework but will be done as soon as is practi-cable.

The following engines which have had field running at the licensees' sites are to be inspected by C.E.S. to determine if cam rollers i have become sluggish and incipient cam scuf fing is occurring. Cam or cam roller scuTfing can be an indication of a worn roller pin -

q or collar. . .

C0:1T Ii!U ED Cl;0VT C11T, r[HNSYLV AHI A 16127

• Pl!0 H L 412 / 4 5 8 8 0 0 0

.-__.-__-_.--~.__,.-_,.._---_Z

. Attachment A - pg 2 of 2 2- flove:aber 3,1978

!!ebr'aska Public Power, Cooper Station, Sff't, 7102 & 7103.

Coranonweal th Ed i son , Zion 1 & 2, SH-7090, 7091, 7092, 7093

& 7094.

The following engines at the licensees' sites which have not had field running are to have the inlet and exhaust valve cross-head assemblies replaced with those of the new design.

Pennsylvania Power & Light,- Susquehanna 1 & 2, SN's 7157, 7158, 7159 and 7160.

Louisiana Power & Light, Waterford 3, SN's 7170 & 7171.

't/ L B. B. Bender Vice President & General Manager CB Reciprocating Products

/jl cc: Ebasco Services, Inc. -

Two Rector Street

• flew Yo rk , N.Y. 10006 ATTN: D. Sandiforth, Supervising Engr.

L. Spinson, Site Quality Program Mgr.

P.O. Box 70

1. 7 Killona, Louisiana 70066 G

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