05000315/LER-1981-026-99, /99T-0:on 810729,missing Bearing Plate Caused Loud Thump to Be Heard by Personnel.Caused by sheared-off Studs Allowing Plate to Fall from Installed Location.Bearing Plate Reinstalled & Readjusted

/99T-0:on 810729,missing Bearing Plate Caused Loud Thump to Be Heard by Personnel.Caused by sheared-off Studs Allowing Plate to Fall from Installed Location.Bearing Plate Reinstalled & Readjusted

ML20010F596
Person / Time
Site:	Cook
Issue date:	08/11/1981
From:	Carteaux P INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20010F593	List: 05000315/LER-1981-026, Forwards LER 81-026/99T-0 05000315/LER-1981-026-99, /99T-0:on 810729,missing Bearing Plate Caused Loud Thump to Be Heard by Personnel.Caused by sheared-off Studs Allowing Plate to Fall from Installed Location.Bearing Plate Reinstalled & Readjusted
References
LER-81-026-99T, LER-81-26-99T, NUDOCS 8109100407
Download: ML20010F596 (2)

LER-1981-026, /99T-0:on 810729,missing Bearing Plate Caused Loud Thump to Be Heard by Personnel.Caused by sheared-off Studs Allowing Plate to Fall from Installed Location.Bearing Plate Reinstalled & Readjusted

Event date:
Report date:
3151981026R99 - NRC Website

text

NRC FORM 3S6 U. S. NUCLEAR REGULATORY COMMISSION LICENSEF EVENT REPORT CONTROL BLOCK: l l

1 l

l l

l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) lo iil l MI Il DI C I CI il@l 0101 - l 010101010 l-1010 l@l 411 l 1 l I l l l@l I

l@

7 8 3 LICENSEE CODE 14 15 LICENSE NUYBEH 25 26 LICENSE T Y PE 30 67 C A1 SH CON'T lolil STR% l L l@l 0 l 5 l 0 l 0 l 0 l 3 ] 1 I ; j@l 0 l 712 l 9 l 8 l 1 l@l 01811 l 1 l 8 l 1 j@

7 6

60 61 DOCKET NUVSER 68 69 EVENT DATE 74 75 REPORT DATE 80

,h EVENT DESCRIPTION AND PROBABLE CONSEQUEN GTTl l ON JULY 27, 1981, AT APPR0XIMATELY 5: M A.M. A LOUD THUMP WAS HEARD BY PLANT I

[o i3; j PERSONNEL WHO WERE INSIDE CONr'NMENT ON ELEVATION 650'.

INSPECTIONS UERE PEP, FORMED l iO i. l lAND ON JULY 29, 1981, ONE OF THE FOUR RESTRAINTS FOR NO.12 REACTOR COOLANT PUMP WAS__j iO isl l FOUND TO BE MISSING ONE BEARING PLATE. THATCONSTITUTEDACONDITIONNOTSPECIFICALLQ io le i LCONSIDERED IN THE SAFETY ANALYSIS REPORT WHICH REQUIRED REMEDIAL ACTION TO PREVENT i

l 0 l 7 ] l DEVELOPMENT OF AN UNSAFE CONDITION.

IN THE EVENT OF CERTAIN POSTULATED PIPE l

i o is i ; RUPTURES, THE BEARING PLATE WOULD NOT HAVE PERFORMED (CONTINUED...)

l SdOOE stegoD

'^"sE C s COOc COYPONENT CODE SU8C DE S

E l0l9l l Cl J l@ l E l@ l B l@ l Sl Ul PI 0] Rl TI8 LX_J@ Lz_j @

7 8

9 10 11 11 13 la 19 zu SEQUENTI AL OCCURRENCE REPORT REVISION LER 40 ENENT YEAR REPORT NO CODE TYPE NO.

@fjgt l8 l1 l l-l l D l2,l (o l [d

l919l lTl

[__j l 0l

_ 21 22 23 24 d6 21 28 29 30 31 32 TAKE A T ON O PLANT T

IIOURS 22 SB IT FOR 5 B.

SUPP LI E MAN FACTURER l B l@l E l@

lCl@

W@

l0l010l0l [Y l@

lN l@

l A l@

lX l9 l9 l9 l@

33 34 35 36 3

40 41 42 43 44 47 CAUSE DESCdlPTION AND CORRECTIVE ACTIONS li)ollTHE STUDS WHICH HAD HELD THE BEARING PLATE IN PLACE HADsSHEARED OFF AND ALLOWED l

li li l lTHE PLATE TO FALL FROM ITS INSTALLED LOCATION.

THE BEARING PLATE WAS REINSTALLED I

i,i7i l AND READJUSTED. ALL OF THE REACTOR COOLANT PUMPS WERE SUBSEQUENTLY INSPECTED l

i 1 13l l AND NO SIMILAR CONDITIONS WERE NOTED.

HOWEVER, ONE OTHER BEARING PLATE ON l

[1 g.] l N0.12 AND ONE BEARING PLATE ON NO.13 REACTOR COOLANT PUMP WERE (CONTINUED...)

l ST 5

% POWER OTHE R STATUS 1 O RY DISCOVERY DESCRIPTION Ii is I l Cl@ l0 l 0 [0 l@l NA l

lBl@l PRE-CRITICALITYINSPECTION l

ACUVITY CON TE NT RELE ASED OF RELE ASE AMOUNT OF ACTIVITY LOC ATION OF RELE ASE LucJ Lz_] @ I z l@l NA l

l NA l

7 8 9 to 11 44 45 80 P:RSCNNEL E xPOSURES l i l 7 l l Ohl 0 l@l z l@lN l

PERSOY.E L INJURIES oEsCniPnON@

Nuvm A li j a l l 0l 01 Ol@l NA l

7 8 9 11 12 80 TY E CtSC PTON l i 19 l l zl@l NA l

80 7

8 9 10 PUON@

NRC USE ONLY ctsCn:

,ss,N Ql NA l

llllllllll]ll}

i i,ini 8109100407 810811 68 69 80 a DR ADOCK 05000 F. CARTEAUX pggyg; WO E4E, N. Wy 3

i SUPPLEMENT TO LER #

SUPPLEMdNT TO EVENT DESCRIPTION ITS INTENDED FUNCTION, WHICH IS TO REDUCE IMPACT FORCES OURING SUCH AN EVENT, i

AND C0l'LD POSSIBLY NOT HAVE PERFORMED ITS INTENDED SEISMIC FUNCTION. THIS REPORT IS BEING StBMITTED PER TECH. SPEC. 6.9.1.8.I.

THIS IS THE FIRST OCCURRENCE OF THIS TYPE.

I SUPPLEMENT TO CAUSE DESCRIPTION FOUND TO BE OUT OF ADJUSTMENT. THESE BEARING PLATES WERE READJUSTED TO l

OBTAIN PROPER CLEARANCES.

TiiE APPARENT CAUSE OF THE FAILURE WAS LOCK-UP 0F THE BEARING PLATE SURFACES DURING MOVEMENT CAUSED BY THERMAL EXPAJSION. AN ENGINEERING EVALUATION IS IN PROGRESS. H0T AND COLD ".LEARANCE MEASUREMENTS WILL BE OBTAINED DURING THE NEXT COLD SHUTDOWN AND ADJUSTMENTS WILL BE MADE IF NECESSARY.

t i.

t i

1

.-,v.+

y-,,--gy-w.y-,r rv..

,-em-vv-w,em--,w,,,m, mm.,

-,v.._

-. +~,<- e -w-,y.,w,,m,- - y-y,.w---,ym

.,w--.,-v,ym,----,-r--,,-._..--,y