ML112410935

Updated LER 80-012/01X-1:on 800317,standby Diesel Generator 1G-31 Lower Crankshaft Thrust Bearing 13 Was Found Wiped on Journal Surface.Caused by Bearing/Crankshaft Clearance Out of Spec & Low Oil Sump Level.Sump Filled.Bearing Replaced

ML112410935
Person / Time
Site:	Duane Arnold
Issue date:	04/24/1981
From:	Rager M IES Utilities, (Formerly Iowa Electric Light & Power Co)
To:	NRC/OI/RGN-III/FO
Shared Package
ML112410936	List: ML112410935 ML20003G634
References
LER-80-012-01X, LER-80-12-1X, NUDOCS 8104300323
Download: ML112410935 (4)

Text

-- REGULATO INFORMATION DISTRIBUTION *TEM (RIDS)

ACCESSION NBR:8104300323 DOC.DATE: 81/04/24 NOTARIZED: NO DOCKET #

FACILt:50-331 Duane Arnold Energy Center, Iowa Electric Light & Pow 05000331 AUTH.NAME AUTHOR AFFILIATION RAGERM.S. Iowa Electric Light & Power Coo RECIP.NAMEi RECIPIENT AFFILIATION Region 3, Chicago, Office of the Director

SUBJECT:

Updated LER 80-012/01X-j:on 800317,standby diesel generator IG-31 lower crankshaft thrust bearing 13 was found wiped on journal surfaceCaused by bearing/crankshaft clearance out of spec & low oil sump level.Sump filled.Bearing replaced.

DISTRIBUTION CODE: A002S COPIES RECEIVED:LTR ENCL SIZE:I - 2.,

TITLE: Incident Reports NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAMEi LTTR ENCL ID CODE/NAME, LTTR ENCL ACTION: IPPOLITOT, 04 3 3 INTERNAL: A/D COMP&STRU06 A/D ENV TECH 07 1 1 A/D MATL & QU08 A/D OP REACT009 1 1

A/D PLANT SYS1o A/D RAD PROT 11 1 1 1 A/D SFTY ASSE12, ACC EVAL BR 14 AEOD AEOD/DMU 3 1f ASLBP/J.HARD AUX SYS BR 15, 1 1 CHEM ENG BR 16 CONT SYS BR 17 1 1 CORE PERF BR 18 DIRENGINEERI20 1 1 DIRHUM FAC 821. DIRSYS INTEG22 1 1 EFF TR SYS BR23 EQUIP QUAL BR25 1 1 GEOSCIENCES 26 I&C SYS BR 29 1 1

I&E 051 JORDANE./IE 1 1 LIC GUID BR 30. MATL ENG BR 32; 1 1 MECH ENG BR 33 NRC PDR 02 1 1 OR ASSESS BR 35, POWER SYS BR 36' 1 1 R AS BR39 REACT SYS BR 40 1 1 01 REL & RISK A 41 1 1 F27I LE STRUCT ENG BR44 GEVA42' EXTERNAL: ACRS 46 16 16 LPDR 03k 1 1 NSIC 05, 1 1 "Mq118

,~O TOTAL NUMBER OF COPIES REQUIRED: LTTR 61 ENCL 61

Iowa Electric Light and Power Company April 24, 1981 DAEC-81-262 Mr. James G. Keppler, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission - Region III 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Licensee Event Report No.80-012 UPDATE REPORT:

(14 day) Previous Report Date 3-31-80 File: A-118a

Dear Mr. Keppler:

In accordance .with Appendix A to Operating License DPR-49, Technical Specifications and Bases for Duane Arnold Energy Center and Regulatory Guide 10.1, please find attached.a copy of the subject Licensee Event Report. (Total of 3 copies transmitted).

Very truly yours, Daniel L. Mineck Chief Engineer Duane Arnold Energy Center Docket 50-331 attachment DLM/'MSR/pl cc: Director, Office of Inspection and Enforcement (40)

U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Director, Management Information and Program Control (3)

U. S. Nuclear Regulatory Commission Washington, D. C. 20555 U. S. Nuclear Regulatory Commission c/o Document Management Branch Washington, D. C. 20555 NRC Resident Inspector - DAEC unne Arnoid Energv Center

• PO. BoN: 351

• Cedar Rapids, Iowa 52406

• 319/851-5611

• NRC FORM 38 NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT *DATE REPORT:

Previous Report Date 3-31-80 81.CK: 1CONTROL (PLEASE PRINT 0R TYPi ALL REQUIRED INFORMATION) 1 6

[7 8 I9 1lAID A IC 11 14 LICENSEE CODE 2 01 01 is

-1 0101 0Q101-UCENSE NUMBER 101q2S )j26 4 111 1 111110 UCENSE TYPE O 57 T 58 CONT REPORT SOURCE _0 0_J~

15 (0 10 1010313 l 1311 17181 1i0141 21 41 RA1li 7 S 60 61 DOCKET NUMBER 48 69 EVENT DATE 74 7S REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES 0 I During the annual inspection of standby diesel gen. 1G-31, the lower 03 crankshaft thrust #13 bearing was found wiped on the journal surface.

04 IFurther investigation revealed bearing/crankshaft clearance out of spec.

F77 Iand low lube oil sump level. Level was maintained in accordance with 0 T"I vendor manual. Redundant standby diesel 1G-21 annual inspection reveal 07 ?ed similar problems (See RO 80-011). Diesel aenerator operability requir 1 8T Iements are given in T.S.3.8.A.2. See also RO Reports 77-32 and 78-020, I 7 89 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUscOO0 COMPONENT COOS SUBCODE SUSCO0E 0] El El I,_XJ I L 1,E1 NI G1 II NI El LLJ IZ 7 8 9 10 It 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION G LER/RO EVENTYEAR REPORT NO. coDE TYPe NO.

--j 1 01 11 21 1 0, 11 [X 1 -- 1_1 REPORT NUMBER L211_J 22 23 24 26 27 28 29 NPRO.4 30 PRIME Como.

31 32 COMPONENT ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT TAKEN ACTION ON PLANT METHOO mouRS SUBMITTED FORM bus. SUPPLIER MANUFACUER 10 10o1 1 L@ j 1JN@ A@ 1C41 71 0 L

33 LO34.. J 1..0@

35 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS It.z.J@

36 36 350~ 370042 40 41 4 . 4334 4447 1 I Vendor study revealed bearina/crankshaft clearance was out of spec. Vend TI Ior analysis resulted in installation of bearings to provide mid-range lo J

[T Iwer crankshaft end float. Lube oil sump was filled: dipstick mark revise 3Ti id per vendor recommendations. Crankshaft was relaDped and Gen. was test- 1 14 Ipd sat. Additional invest.. reqd due to problems found during 1981 refuel. I so FACILITY METHOD OF STATUS %POWER OTHER STATUS - ISCOVERY DISCOVERY DESCRIPTION 15 - 0 1 0.01 JI1 NA I 1IB Annual Surveillance Test 7 8 9 10 12 13 4 45 46 80 ACTIVtTY CONTENT 12 1 RELEASED *OF RELEASE AMOUNT OF ACTIVITY LOCATION OF AeLE 1 L.zi@ .zJl NA I NA 7 a 9 TO I1 4 5 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION I I1 01 01 0o1 z ICI 7 8 9 11 12 13 80 PERSONNEL INJURIES NUMBER OESCRIPTION 1 01 QlI NA 7 8 9 11 12 80 LOSS OF OR DAMAGE TO FACILITY TYPE 0ESCRIPTION 7

T 8 9 Wl1 110 NA 80 PUBLICITY NCUEOL ISSUED DESCRIPTION NRC USE ONLY NL.i@ NA 11111111111lI 7 8 9 10 68 69 80.

NAME OF PREPARER Matthew S. Rager P .ONE: 319-851-5611

)UANE ARNOLD ENERGY CENTER Iowa Electric Light and Power Company LICENSEE EVENT REPORT-Supplemental Data Docket No. 050-0331 Licensee Event Update Report: April 24, 1981 Reportable Occurrence No: 80-012 UPDATE REPORT:

Previous Report Date 3-31-80 Event Description During the annual inspection of standby diesel generator 1G-31, the lower crank shaft #13 thrust bearing was found wiped on the journal surface. Further investi gation revealed that the lubrication oil sump level was low such that there may have been insufficient lubrication of the #13 thrust bearing. Redundant standby diesel generator 1G-21 annual inspection revealed similar problems (See RO Report 80-011). Although both diesel generators were operable at the time of the surveil lance testing, extended operation, without corrective action, could have resulted in the bearing failure. Standby diesel generator operability requirements are listed in Technical Specification 3.8.A.2. There have been two similar RO Reports previously submitted (See RO 77-32 and 78-20). This unit is a Fairbanks Morse Model 3800 TD8-1/8.

Cause Description Vendor representative indicated the diesel #13 thrust bearing to crankshaft clearance was found out of specification (too small). Vendor analysis recommended the instal lation of bearings to provide for mid-range lower crankshaft end float. The engine lube oil sump level was maintained in accordance with the manufacturer's technical manual. However,.the vendor representative indicated that the level was incorrect.

The "full" mark on the sump dipstick was relabelled."running full" and a new higher "shutdown" full level mark was added to the stick to preclude improper sump fill in the future. Although insufficient lubrication may or may not have contributed to this event, lack of lubrication could have eventually caused bearing failure.

Corrective Action The diesel thrust bearing'was replaced with a factory modified bearing to provide the recommended clearance. The diesel generator was reassembled and retested satis factorily.

The lubrication oil sump dipstick was marked to indicate a full level position with the unit shutdown in addition to the full level position when in the operating mode.

This relabelling of the dipstick should eliminate improper sump filling in the future.

Oil was added to fill the sump-to the proper level. The appropriate operating procedure has been revised to reflect the new dipstick markings.

Additional engineering investigation work is planned since a similar wiped bearing problem was discovered while performing the annual inspection of standby diesel generator 1G-31 during the 1981 refueling outage.

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