05000483/LER-1989-001, :on 890207 & 15,diesel Generator Train B Declared Inoperable When Fuel Oil Transfer Pump Failed to Autostart During Surveillance Test.Caused by Failure of Main Control Board Switch Contacts.Switch Replaced

:on 890207 & 15,diesel Generator Train B Declared Inoperable When Fuel Oil Transfer Pump Failed to Autostart During Surveillance Test.Caused by Failure of Main Control Board Switch Contacts.Switch Replaced

ML20247G842
Person / Time
Site:	Callaway
Issue date:	07/21/1989
From:	Blosser J, Taylor M UNION ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-001, LER-89-1, ULNRC-2042, NUDOCS 8907280194
Download: ML20247G842 (6)

LER-1989-001, on 890207 & 15,diesel Generator Train B Declared Inoperable When Fuel Oil Transfer Pump Failed to Autostart During Surveillance Test.Caused by Failure of Main Control Board Switch Contacts.Switch Replaced

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(1)
4831989001R00 - NRC Website

text

ET 4

~,

4 t F.3

.y Gygoy

. Etscraic.

. n

. Ca#away Plant.

July 21, 1989 IU. S. Nuclear. Regulatory Commission

. Document, Control Desk Washington, DC. 20555 ULNRC-2042 Gentlemen:

. DOCKET NUMBER.50-483 CALLAWAY PLANT-UNIT 1 FACILITY OPERATING LICENSE NPF-30 LICENSEE EVENT REPORT 89-001-01 AN EMERGENCY DIESEL GENERATOR WAS DISCOVERED TO HAVE BEEN INOPERABLE DUE TO A' FAILED MAIN CONTROL BOARD SWITCH The enclosed Licensee Event Report is submitted pursuant to 10 CFR 50.73(a)(2)(1) concerning operation of the Callaway Plant with a condition prohibited by the plant's Technical Specifications. This condition resulted when the 'B' Diesel Generator was discovered to have been' inoperable without the Technical Specification action requirements being met. The condition is also reported as a valid failure of 'B' Diesel Ger4erator.

ole.

M

. D, Blosser g ) Manager, Callaway Plant y

TPS/JKB: jew i

Enclosure

.ce: Distribution attached l

i 8907280194 890721 I

i PDRs ADOCK 05000483

+-

S-PDC

. I

~

~w 9_

Maiky Adkoss* PO. Box 620, Fulton, MO 65251

ce distribution for ULNRC-2042 '

Mr. A. Bert Davis Mr. Thomas Alexion (2 copies)

Regional Administrator Office of Nuclear Reactor Regulation U.S. Nucicar Regulatory Commission U. S. Nuclear Regulatory Commission Region III Mail Stop 13-E-21 799 Roosevelt-Road Washington, D.C.

20555 Clen Ellyn, IL 60137 American Nuclear Insurers Mr. O. Maynard c/o Dottie Sherman, Library Wolf Creek Nuclear Operating Corp.

The Exchange Suite 245 P. O. Box 411 270 Farmington Avenue Burlington, KS 66839 Farmington, CT 06032 Mr. Merl$n W1111ams Manager, Electric Department Supt. of. Regulatory Quality &

Missouri Public Service Commission Administrative Services P. O. box 360 Wolf Creek Nuclear Operating Corp.

Jeffercon City, MO 65102 P. O. Box 411 Burlington, KS 66839 Records Center Institute of Nuclear Power Operations Mr. R. W. DeFayette Suite 1500 Chief, Project Section 3A 1100 Circle 75 Parkway U.S. Nuclear Regulatery Commission Atlanta, GA 30339 Region III 799 Roosevelt Road NRC Resident Inspector Glen Ellyn, IL 60137 D. F. Schnell-(400)

G. L. Randolph R. P. Wendling (470)

J. V. Laux A. C. Passwater/D. E. Shafer/D. J. Walker (470)

G. A. Hughes l

Z170.03 (QA Record) 240LER (Z170.09 Commercial Record)

M. S. Evans M. E. Tayler H. Wuertenbaccher, Jr. (100)

S. L. Auston (470)(NSRB)

S. J. Bellers/D. R. Delrichs E210.01 Z40ULNaC A160.761 N. Date (Sandra Auston) (470) l l

!.~

j N tC Fe' e 366 U E. NUCLEAR REGULATORY COMMtE& ION r

APPROVED OMB WO 3160 0104 l

LICENSEE EVENT REPORT (LER)

F X PiR E S O '31 88 l

I F ACILITY NAME Mi DOCRET NUMBE R (2) 6' AG E 4 3:

Callaway Plant Unit 1 o 151010 [ 0 { 4I8 I 3 1 lOFl0 l 4 TITLE 14)

An Emergency Diesel Generator Was Discovered To Have Been Inoperable Due to a TN41oA W in Cnnern1 Rnnyd %4tch EVENT DATE (Si LE R NUMBE R 46)

REPORT DATE 171 OTHER f ACILiflE$ INVOLVED 151 U

MONTH DAV WEAR Vf.AR

(* '

{#

MON T H DAY T F AFL

$ ACils T V NAMF5 DOCKE T NUMBE MISI O 15101010 1 1 1 0l 2 0l7 8

9 8j9 0l0l1

~~

0l 1 0 l7 2 l1 8l9 0l5 1 01 0 ioi j l THis ReeOR, is U.MiTTED PURSUANT TO HE REOU.REMENT OF 0 C, R,,c.<...,,,.....,,,,,

uo.-,, n i i o,,,,,,,

MODE Mil

}

20 402thi 20 405ter 50.736 112664.p 73 711bl POWER 20 406te 41Hd 50 384eH16 60.731sH2Hvl 73 71tal LEVEL

}l0 0 X_ gEgs-4,, g e 1

20 40si.Huw s0 364.H2>

.0 7m.H24. o 110)

[

20 406toH1Hin)

X 60.73(eH2 H d 60 73(aH2nureeHAl Jo6M 20 4061 H1H6vi 60 73teH2H40

1. 0 734.H2HvoiHB) 20 4091sHi tM

$0.7tsH2Hm)

B0 73 aH2Hal LICENSE E CONTACT FOR THt5 LIR 112)

NAME T E LEPHONE NUMBEH M. E. Taylor - Superintendent of Operations aE A cet 3l114 617161 -1812 p 17 COMPLETE ONE LINE FOR E ACH COMPONENT F AILURF OtsCRisED IN THis REPORT d131 "I' " ^

[E REjD "

E

CAUSE

$v5TtM COMPONENT tD NPRD5' CAU$E S y rT E a,*

COMPONENT PH X 'Dp lH l1lS El1 l5 l 5 N

l

! l l l l l l

l 1 I I I I I

I I I I I I SUPPLEMENT AL REPORT E kPE CTED #141 MONTH DAY YEAR 508 Mis &60N YE 5 In,,s conur'ere E APCCT ED $UB4HS$ ION DA TEI No l

l l

Aw R ACT w-n, a,w.,

...,,,,0-,,e wa.,.n

,n, r.

- H.,

....a o s,

At 0400 CST on 2/15/89, Diesel Generator (D/G) train

'B' was declared inoperable when the fuel oil transfer pump failed to autostart during a surveillance test. Troubleshooting determined the cause to be a faulty Main Control Board (MCB) switch. The MCB switch had disabled the fuel oil day tank level cwitches and the local handswitch.

Consequently, the transfer punp was not capable of automatically supplying fuel to the day tank. This condition had existed since 2/7/89., Technical Specification actions were not initiated until discovery at 0400 on 2/15/89 and, therefore, exceeded the allowed time limits. The plant was in Mode 1 Power Operation at }00%

reactor power.

The root cause of this event was the failure of the MCB switch contacts. The l

esuae of the open switch contacts was most likely due to mechanical binding.

The MCB switch was replaced. The problem was not detected on 2/7/89 because the day tank level red been vanua11y maintained above the low-level svicch setpoint. The event vill be reviewed by Operations personnel and the log sheets will be revised to allow the pump to automatically maintain the fuel level.

l l

l

(

NRC Form 366 L___ _ _..___MfW _ ____. _ _ _

f

!L N c nem posA u.s. NUCLEAR #;EautAroav couMissiom LICENSEE EVENT REPORT (LER) TEXT CONTINUATION ApenovEo oMe No. siso-oio4 EXPIRES 8/31/80 F ACILITY NAME 11)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE Ol sw

=m Callaway Plant-Unit 1 0 j5 l0 l0 l0 l4 l 8l3 8l 9 0l0l1 -0 l1 0 l2 OF 0h iEXT in more space a requored, use addinonalNRC Form &l6ks)(17)

Basis for Deportability At 0400 CST on 2/15/89, emergency Diesel Generator g G)(1) train'B' was declared inoperable when the fuel oil transfer pump failed to autostart during its monthly surveillance. Subsequent trouble ting determined the cause to be a faulty Main Control Board (MCB) switch Because other evidence indicated that this condition had existed on 2/7/89, the D/G was determined to have been inoperable from about 0400 on 2/7/89 until 2225 on

~2/15/89. Technical Specification (T/S) 3.8.1.1 actions b and d were not initiated until discovery of the condition at 0400 on 2/15/89 and, therefore, exceeded the allowed time limits. This report is submitted pursuant to 10 CFR 50.73(a)(2)(1) as a condition prohibited by the plant's T/S.

Also, this event is reported as a valid D/G failure per T/S 6.9.2 and T/S 4.8.1.1.3.

Conditions at the Time of Discovery and the Event Date Mode 1 - Power Operations, 100% Reactor Power Description of the Event On2/7/89atabout0400, anon-licensedEquipmentOperator(EO)dgovered during his watchstation rounds that the D/G 'B' fuel oil day tank standpipe level was indicating about 5 ft., which was below the 5.5 ft.

minimum level on the watchstation log sheet. He attempted to start the D/G

'B' fuel oil transfer pump in order to fill the day tank. Hedisgeredthat the transfer pump could not be operated from the local handswitch and therefore notified the control rcom of the problem. A licensed Reactor Operator (RO) momentarily ran the pump from the MCB switch to raise the day tank level. The uansfer pump shut off immediately when the switch was

{

released. The RO assgd that the putap stcpped at the standpipe high-level (9 ft.) cctoff switch because very little time is needed (about 2 secs.)

to fill the sta,dpipe volume. Due to the short period taken to fill the standpipe, there was no indication of a problem with the MCB switch. The EO verified that the standpipe level was satisfactory and wrote a work reouest for the local handswitch.

On 2/15/69 at 0400 during a monthly survrillai.ce tesgthe transfer pump failed to autostart at the day tank low-level switch setpoint. D/G train

'B' was declared inoperable. Instrumentation and Controls technicians and electricians were dispatched to troubleshoot. The standpipe and day tank l

l level switches were tested and functioned properly.

In addition, i

electricians troubleshooting the local handswitch could find no problem with j'

it.

The problem was then traced back to the MCB switch where 'wo I

normally-closed contacts were found to be open, disabling the standpipe and day tank level switches and the local handswitch. Consequently, the transfer l

pump was not carable of automatically supplying fuel to the day tank. The wac ronu maa au.s. cro, tess-szo-sev.coc7o m

___-__-_-__.__--__-.__-___--___a

L NRC Form yA U.S. NUCLEAR 0;EGULATO3Y COMMitSION LICENSEE EVENT REPOHT (LER) TEXT CONTINUATION APPROVED OM8 NO. 3150-0104 EXPIRES: 8/31/88 ILITY NAME 4H i G KET NUMSER (2)

D LER NUMBER 46)

PAGE (3) l..

ygan

. st out NTi A L.," ""

Mtv msuN Callaway Plant Unit 1 o l5 l0 l0 l0 l41813 8l 9 Ol d 1 0l 1 0l3 M 0l4 TEXT 191more spece Au requerd, une addtaann! NRC Form 30$kel(11)

'MCB switch had to be held in the "RUN" position for the pump to continue to operate. Therefore, the D/G was determined to have been inoperable since 2/7/89. The MCB switch was replaced and all components were surveillance tested satisfactorily. D/G train 'B' was returned to service on 2/15/87 at 2225.

Root Cause The root cause of this event was the failure of the MCB switch contacts.

The cause of the open switch contacts was most likely due to mechanical binding of the cams. Upon removal of the switch, the two contacts were found to be closed (their normal position). Dismantling the switch did not reveal any other reason which might have caused the failure.

Acontributingfactorwasthattheadministrativelimi[87f 5.5 ft. on the E0 log sheet was set above the stande.pe low-level switch setpoint.

Consequently, the standpipe level was never allowed to reach the low-level setpoint at which the control circuit failure could have been detected.

Corrective Actions

The MCB switch was replaced and all components were surveillance tested satisfactorily. The Nuclear Plant Reliability Data System (NPRDS) and plant experience were reviewed to ensure that the switch failure was not a generic concern. This event will be reviewed by Operations personnel so that similar failures might be more accurately diagnosed. The EO watchstation log sheet will be revised to allow the transfer pump to maintain the standpipe level automatically.

Safety Significance

Offsite A. C. sources and D/G 'A' were continuously available during this event and were capable of supplying power to all safety related loads. D/G

'B' could also have supplied power in an emergency.

If a start had occurred, D/G 'B' would have started and run.

At a level of 26,9 inches (sufficient fuel for approximately one hour of engine operation), a non-safety related MCB annunciator (window 90C) vould have actuated indicating the low day tank level.

Close wonitoring of the day tank level would have. been required since the MCB switch had to be continuously held for the transfer pump to operate.

This event posed no threat to the public health and safety.

This event is also considered a valid D/G 'B' Failure per Regulatory Guide 1.108.C.2.e.(8).

The surveillance test interval of T/S Table 4.8-1 is not affected. The starting history of D/G 'B' as of the event date is summarized as folloss:

wnceomu :)ana

• U.S. CPOJ t*66-$2 M P9 W V 70

_3 8?! _ _ ____

NRC Foem,346A U.S. NUCLEAR KEOULt.TO;Y COMMISalON LICEN EE EVENT REPORT (LER) TEXT CONTINUATION A*movEo cme No. 31so+o4 EXPIRES: 8/31!80 P ACtLITY NAME (1)

DOCKET NrJfdBf 6 (2)

LER NUMBER (66 PAGE (3) p

.Callaway Plant Unit 1 o l5 l 0 j o l 0 l4 l 8 l 3 8]9 0 l 0l 1 0l1 0l4 OF 0l 4 TEXT tilmens spece k reemrod. use edditanaf NRC Form JtlM's!(17)

No. of Failures No. of Failures No. of Valid Tests During Valid Tests During Invalid Tests 70 1

2#

1. Reference Special Reports 85-05 and 89-01.

Surveillance tests are currently performed at least once per 31 days for the

'B' D/G. This is in conformance with the schedule of T/S Table 4.8-1 which requires a test interval of not more than 31 days if the number of failures in the last 20 valid tests is one or less or the number of failures in the 1ast 100 valid tests is four or less.

Frevious Occurrences None.

Footnotes The system and component codes listed below are from IEEE Standards 805-1984 and 803A-1983, respectively.

(1) System - EK Component - DG (2) System - DC Component - P (3) System - DC Component - HIS (4) System - DC Component - TK (5) System - DC Component - HS (6) System - DC Component - LS (7) System - DC Component - LS (8) System - DC Component - LS l

.v... cm, i...mo m.a w.

N24,OaM3A