05000301/LER-1979-002-03, /03L-0 on 790227:during Biweekly Test of a Reactor Trip Breaker,Several Seconds Elapsed Following Trip Signal Before Breaker Tripped.Caused by Faulty Reactor Trip Relay,Westinghouse BFD31.Relay Replaced

From kanterella
(Redirected from ML19276F329)
Jump to navigation Jump to search
/03L-0 on 790227:during Biweekly Test of a Reactor Trip Breaker,Several Seconds Elapsed Following Trip Signal Before Breaker Tripped.Caused by Faulty Reactor Trip Relay,Westinghouse BFD31.Relay Replaced
ML19276F329
Person / Time
Site: Point Beach NextEra Energy icon.png
Issue date: 03/13/1979
From: Burstein S
WISCONSIN ELECTRIC POWER CO.
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19276F325 List:
References
FOIA-79-149 LER-79-002-03L, LER-79-2-3L, NUDOCS 7903280354
Download: ML19276F329 (2)
v • d • e


LER-1979-002, /03L-0 on 790227:during Biweekly Test of a Reactor Trip Breaker,Several Seconds Elapsed Following Trip Signal Before Breaker Tripped.Caused by Faulty Reactor Trip Relay,Westinghouse BFD31.Relay Replaced
Event date:
Report date:
3011979002R03 - NRC Website
v • d • e

text

T.

ATTACHMENT TO LICENSEE EVENT REPORT NO. 79-002/03L-0 Wisconsin Electric Power Company Point Beach Nuclear Plant Unit 2 Docket No. 50-301 While performing the bi-weekly test of the Unit 2 reactor trip breakers at 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br />, February 27, 1979, several seconds elapsed following the application of a trip signal before the "A" breaker tripped.

Subsequent investigations discloned a faulty reactor trip relay (RT-3).

The relay, a Westinghouse Catalog No. BFD 31 (DC), failed to drop out promptly due to excessive plunger-to-sleeve friction resulting from sleeve deterioration.

The high temperatures of operation of this normally energized relay had caused the nylon sleeve in the center of the coil to deteriorate and crack.

Interference between the cracked sleeve and the solenoid plunger prevented the relay from promptly dropping out.

The relay was replaced at 1115 hours0.0129 days <br />0.31 hours <br />0.00184 weeks <br />4.242575e-4 months <br />, February 27, 1979, and a retest was satisfactorily performed.

A similar event occurred July 5, 1978 (Licensee Event Report No. 78-008/03L-0) in which a reactor trip relay failed to drop out due to nylon sleeve deterioration.

This previous failure prompted the decision to replace all relays of this type associated with the reactor trip system.

The Unit 1 relays were replaced during its 1978 fall refueling.

The Unit 2 relays will be replaced as soon as practicable.

The new relays will be the type recommended by Westing-house in their technical bulletin NSD-TB-76-16.

Westing-house's new BFD relays are designed to correct both coil-sleeve deformation and pin hang-up problems.

The coil bobbin material being a thermosetting material as opposed to a thermoplastic specification is more suited for use at a much higher temperature.

The magnet anti-stick disks which ensure that residual magnetism will not allow the relay to remain closed is soldered in as opposed to epoxied.

The armature pin is epoxied to the cross bar to eliminate any chance of rubbing on the external case and causing a relay malfunction.

7 90 3 28 0 36N

NRC FORM OGG U. S. NUCLE AR REGULATORY COMMISSION (7 7h LICENSEE EVENT REPORT CCNTROL BLOCK: l l

l l

l l

h (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATIONI i

c lWlIlPjBlHj2l@l0l0l-j0 010l0 O f - 0 l 0 @l 4 l 1 l 1 l 1 1l@l l

l@

o l

- 3 LICENSEE CODE 14 15 LICENSE NeveER

.o

6 LaccNSE TYPE JO S1 w A I 58 CCN'T [g"y l L l@l 015 l 0 l 0 l 0 l 3 l 0 1 @l 0 l 212 l 7 l 7 l 9 @l nl1 l 1 l117 o l@

o 1

to 61 DOCK ET WVBER bd 59 EVENT D ATE 14

'S REPORT O AT E t0 7

EV ENT OFSCRIPTION AND PROB ABLE CONSECUENCES h 0 12 lAt 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br />, 2-27-79, during the bi-weekly test of the "A"

reactor I

trip breaker (one of two), several seconds elapsed followinc the apoli-I o

3,

cation of a trip signal before the breaker tripped.

A faulty reactor i

o 4

ois j trip relay (RT-3) was the problem.

A similar event occurred 7-5-78 (LERl 3 93 q 78-008/03L-0).

Sinca the breaker did trip and the test of the redundantl 3l7; ["B" breaker was satisfactory, the safety of the public was not affected.1 i a y

j This event is reportable per T.

S.

15.6.9.2.B.l.

I 6J 3

,3 3

SYSTEN1 CALSE CALvd COYP VAL.E COCE COCE SLBCOCE CCVPCNENT CODE SLBCOCE 3v3COCE l Il Al@ l E @ l A l@ l RlEl L l A l Y lX @ l A @ lZl@

a 9

7 8

9 10 it 12 13 td la Zu SE QUENTI AL CCCUAAENCE R E POR T REV;SiON E%ENT YE AR REPORT NO.

CCOE TYPE NO

@ (gga pg l217 l 9l

- l l 010l 2l

/l l0l3l lLl l-l l0l E.g 22 23 24 26 27 23 29 JJ 31 32 ACTION SUTUAE EFEECT S H U T O C V.N ATT AC HV E N T NP R C-4 PR6VE COMP COYPONENT TAKEN ACTION CN PLANT VETHCD HOURS SLBUITTED

FORVsV8, SUPPLIER VANLFACTUAER l C l@l X l@

lZl@

lZl@

l0l0l0l0 [Yl@

Yl@

Nl@

lW ll2 0 l@

JJ 34 35 36 3e 40 41 42 43 44 47 CAUSE CESCRIPTION AND CORRECTIVE ACTIONS h lA Westinghouse Cataloc No. BFD31 (DC) relav failed en a v-

~r

- ---

  • 1 7 1 i

a di ae to excessive plunger-to-sleeve friction resultinc from sleeva I

3

[ deterioration.

The high temperatures of operation had caused the coil'sI i,, l nylon sleeve to deteriorate and crack.

The relay was reolaced at 1115 l

l hours, 2-27-79, and a retest was satisfactorily performed.

I 2

g,

so T

S N POV.E R OTHER STAT'.;S S OV RY 06SCCVERY DESCR:PTION l El@ l1l 0 0l@lN/A l

l B l@l Technician observation l

t 5

7 3 3 10 12 13 44 45 46 30 ACTIVliv CONTENT AtLE ASED CF AELE ASE AVOLNT OF ACTivlTY LOCAT'ON OF RE LEASE -

W @ l 2 l@l N/A l

l N/A l

i 6

3 3

10 11 44 45 sJ PERSCNNEL EXPCSLRES NLVaER TYPE D E SC AlpT:CN i

- 10 l 010!@l Z I@l N/A I

.i

)

11 12 13 30 PE ASONNE L ' nURIE3 CESCR,PTiCN@

u.m A 1010101@l N/A l

i i

)

11 12 SJ LOZ CF OR O avage TO F ACILITY T.pE 3E5CpiPTlON lZ l@l N/A l

i

,L c

PLu C Tv c

sac usa cNtv

.n !D m 3E5CR'P90N O i

$l N/A l

ll l t!IIIII II l' 3

a a e so ;

Sol BurStein 414/277-2121 2,

NAME CF PREPAREp P"CN E.

Retrieved from "https://kanterella.com/w/index.php?title=05000301/LER-1979-002-03,_/03L-0_on_790227:during_Biweekly_Test_of_a_Reactor_Trip_Breaker,Several_Seconds_Elapsed_Following_Trip_Signal_Before_Breaker_Tripped.Caused_by_Faulty_Reactor_Trip_Relay,Westinghouse_BFD31.Relay_Replaced&oldid=4843157"