ML20011F194

Part 21 Rept Re Abb 27/59 Relay Catalog Series 211L.Solder Connections to Printed Wiring Runs on Bottom of Circuit Board Deteriorated Due to Thermal Stress.No Actual Failure Occurred & Relays to Be Changed at Next Outage

ML20011F194
Person / Time
Site:	Beaver Valley, Browns Ferry, Perry, Fermi, Sequoyah, 05000000
Issue date:	02/22/1990
From:	Kaiser A ASEA BROWN BOVERI, INC.
To:	Berlinger C Office of Nuclear Reactor Regulation
References
REF-PT21-90-030-000 PT21-90-030-000, NUDOCS 9003020075
Download: ML20011F194 (3)

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' r ft ASEA BROWN BOVERI L iFebruary:22."1990 Mr. Carl Berlinger, Branch Chief s

office of Generic Communications

.U.S.: Nuclear Regulatory Commission Washington,-D.C.- 20555

Subject:

- 10CFR Part'21 Report s  !

'ABB 27/59 Relay.  ;

Catalog Series 211L a

~Gentlement-1An.ABB'27/59' Relay (Catalog No. 211Lil75) was returned by CEI Perry Nuclear Station ~for evaluation. Examination has revealed that six (6) solder .

connections,1where the leads from three (3) wire wound 3 watt resistors  !

connect to the printed wiring runs on the bottom of the circuit board.:have  !

. deteriorated due.to thermal stress. The resistors are-designated R38, R39 and: l l  : R41' on the circuit' board.-

'The printed wiring patternt'uses pads of only 1/8 inch diameter at these-locations.: The heat is dissipated in the wire wound resistors and:isi >

L , conducted tiirough the leads of. the resistors to these pads. It is-also '[

n radiated from the body of the-resistor to the board below.. This thermal stress has: caused the bond.of-the printed: wiring pattern to the glass epoxy

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& . circuit' board to: show discoloration -and the pads have 1if ted f rom the surf ace

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of the board. This#jeopardizesithe integrity of the connections. No actual.

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. failure has occurred, however should the connection fail,:the; relay would not*

~ operate properly. The likely failure mode for Catalog Number 211L1175, would o be.tofgo into an "Undervoltage" condition. -

P -ABB proposed to CEI.to furnish an interim circuit board with provisions for- '

'< ' adequate heat; dissipation. These boards'could be changed out'one at a time L since-the plant is in operation. It was also proposed that these relays be- '

. changed out at the'next outage with different model relays. CEI has advised

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[ ' ABB: that, they are' evaluating their procedures for alternatives to circuit, y board or relay replacement. ,

j The' newer model relays have substantially larger pads- and higher wattage

rating' resistors to lower the operating temperature, and avoid the conditions ' f s listed-previously.

'These 211L relays are used in other nuclear stations and are listed in Appendix "A". It is believed that the relays installed at.the TVA Browns >

Ferry!and-Sequoyah plants were replaced with the ABB 27N relay to obtain a f

higher set point accuracy, and therefore 'will not have this condition.

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> I 9003020075 90022 e ,

PDR E '

A ADOCK 05000 59 PDC. h ABB Power Distribution Inc.

AB8 Powet oistreuhon inc. Telephone. Telefax.

201 Hekman Drive 407 323 8220 407 322 8934 Po. Box 1978 o i < Sanford, FL 327721978 - i, i

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._Mr. Carl Berlinger #

U.S. Nuclear Regulatory Commission February 22,.1990 Page 2 The: relays in the switchgear at PSI Marble Hill (cancelled) may have been resold to other plants or users. ABB has no knowledge of their current location. '

Detroit Edison (Fermi) cnd Duquesne Light (beaver Valley) should contact ABB ,

= for recommended corrective action depending upon the application of these relays -

The quantity of relays listed in Appendix "A" includes the total number of ,

relays at.each location. Not all are used in Safety Related app 12 cations. I Also, the relays may be identified as "1TE" 27/59 rather than ABB 27/59.

J Copies of this report are being sent to the nuclear, stations listed in Appendix "A". >

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' A. F. Kaiser, Presiden't ABB. power Distribution Inc.

EWR/jm

-Attachment J cc: K. Naidu-9.s \ i Q'q/. ,

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APPENDIX "A" il .

Company Station -SUj( Relay S.O. Switchgear S.0, CEI . .

Perry 48 ---- 33-51959 (211L1175)

Detroit Edison Fe rmi '12 34-31322 ----

(211LO275)-

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.Duquesne Light ~ Beaver 2 34-34310 ----

(211LO275) Valley 2 34-34717 ----

Y PSI Marble Hill 12 34-39971 33-52213

'(211Lil75) 12 34-39902 33-52213 f

TVA .

Browns Ferry 13 34-38625 ----

L(211LO175)

? TVA 'Sequoyah .12 34-42905 -----

(211L0175) l i

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