ML20073J521

Part 21 Rept Re Likely Failure of post-LOCA Hydrogen Recombiner Component,Dpst Toggle Switch 12TSI-2 Due to Aging & Radiation.Field Bulletins Issued to Install Jumpers Bypassing Switch

ML20073J521
Person / Time
Site:	Hatch, Nine Mile Point, Fermi, Limerick, LaSalle, 05000000, Shoreham
Issue date:	12/14/1982
From:	Empey D ROCKWELL INTERNATIONAL CORP.
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
REF-PT21-83 82ESG-8933, NUDOCS 8304190318
Download: ML20073J521 (6)

Text

.

~~

• a ,

Energy Systems Group 8900 De Soto Avenue Canoga Park, California 91304 Rockwell Teiephoneg2133 34i iOOO International TWX: 910-494-1237 Telex:181017 December 14, 1982 In reply refer to 82ESG-8933 U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive Arlington, Texas 76012 Attenti.on: Mr. John Collins, Administrator Region IV

References:

ESG Letters, D. C. Empey to John Collins, 82ESG7725 dated October 21,1982; 82ESG8085 dated November 3,1982:

and 82 ESG7948 dated November 3, 1982.

Gentlemen:

Subject:

Report of Defect (10CFR21)

As a result of ESG's IEEE 323 qualifications testing as described in each of the References, the post-LOCA Hydrogen Recombiner component noted below has been determined to be likely to fail due to a combination of aging and radiation.

COMPONENT DESCRIPTION Microswitch, DPST toggle switch, rated 15A,125-250 VAC; hp, 125 VAC, P/N 12TSI-2.

Test Results During the IEEE Environmental Qualification testing, both poles of the switch failed to close when the switch was actuated during the post-LOCA environmental cycling test. During the post-seismic functional test, the switch operation appeared to be weak and not firm as normal. Disassembly and examination of the switch revealed that the plastic sliders were missing and there was considerable debris around the operating handle. The failure analysis of this component concluded that the plastic slider was sufficiently degraded during the thermal and radiation aging that it broke into many pieces due to the vibration and shock from the seismic test and snap action when operated.

The switch is used in the control circuits of the reversing motor starters for the hydrogen recombiner motor operated valves (3). The switch is normally closed and if the slider broke following a LOCA (due to some seismic or other forces), the switch could open and disenable the operation of the motor operated valves. Thus the safety function of the hydrogen recombiners could be impacted.

8304190318 821214 # '

C PDR ADDCK 05000322 S PDR

- sj ~. ",

v w

Mr. John Collins, Administrator Page 2 Region IV December 14, 1982 U.S. Nuclear Regulatory Commission 82ESG8933 Corrective Action / Comments

- The purpose of the switch is to permit dis-enabling the motor starter con-trol circuit during periods of trouble-shooting the electrical system and is not essential for design or operation. Recent designs have eliminated the switch. Field bulletins have been issued to install jumpers bypassing the switch such that recombiner operation, in performance of its safety function, it not impacted by the switch.

Affected Plants NRC Licensed Customer Name Facility / Activity G0 {Ltjt Date Shipped Detroit Edison Fermi 2 NPS 04056 2 08-76 Long Island Lighting Co. Shoreham 1 NPS 04093 2 02-22-77 Philadelphia Electric Limerick 1 & 2 NPS 04097 4 06-30-77

. Company Georgia Power Co. Hatch 2 NPS 04154 2 06-14-77 (1)

Niagara-Mohawk Power Nine Mile Point 04193 2 02-23-79 Corporation 2 NPS

. Commonwealth Edison Co. LaSalle County 1 & 04198 2 08-29-78 (1) 2 NPS NOTE: (1) Operating Plant Notifications Each listed plant operator has been notified of the results of our IEEE-323 qualification testing along with the above mentioned bulletin on bypassing of the switch. Additional components which failed to function properly following the qualification program are given in the References.

p :, ,

>b4 Kl ca Mr. John Collins, Administrator Page 3 Region IV December 14, 1982 U.S. Nuclear Regulatory Commissiun 82ESG8933

. If you require further information or clarification, please call me at (213)700-3926.

Very truly yours, D. C. Empey Director Quality Assurance cc w/ enclosure cc: (3) Director, Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555

Enclosure:

Bulletin No. LAS-6

G ', . . ,

N1160MM120002 aut r m sc. LAS-6

1. h% Rockwet!I intemanona: TECHNICAL SERVICES o^" 11 Oct 82 i

" ' ~ ' "' I

• 3 FIELD ENGINEERING BULLETIN put $23 K 23 Nty. 5 7E La Salle County Station APPLICABLE TO: Commonwealth Edison Company Thermal Hydrogen Recombiners Serial Nos. 211A and 211B

SUBJECT:

Operation of Hydrogen Recombiner System With Disconnect Switch Part Number 9422-RC-1 an.1 Micro Toggle Switches Part Number 12TSI-2 Bypassed.

REFERENCE:

Operation anc Maintenance Manual N1160MM120002 Thermal Hycrogen Reccmbiner System.

PURPOSE: To provide instructions for bypassing (a) the main disconnect switch, HS-10, for the recombiner skid 480 Vac 3-phase, power

- bus for inlet, recirculating gas and cooling water valve operator circuits, and (b) the three micro tcggle switches that act as disconnect switches for the inlet gas, MS-11, recirculating gas, HS-12, and cooline water valve, HS-13, operator motor starters.

NOTES: 1. The subject switches failed during IEEE environmental qualification testino.

2. The bypassing of the disconnect switch and micro toggle switches will not compromise the safety or reliability of the recombiner system.

3. The disconnect function will revert to the valve operator switch in the control cabinet.

4. The instruction sheet (builetin) used when performing this modifica-tion shall be signed by a f,uality Assurance Mar.ager at:d a copy of the signed sheet must be rr.turneo to ESG as follows:

Rockwell International Energy Systems Group 8900 De Soto Avenue Canoga Park, California 91304 Attention: Don Empey, r344 731-2.229/arb Change No. 3 - October 15, 1982 D-9 DE3IC'IA C ORIGlKAL 3rtified E:7 b

o, ..',

- - . N1160Mt1120002 suttsTis so LAS-6

^re. 11 Oct e Rockwelllntemational TECHNICAL SERVICES

' ~ ' " " . 2 o. 3 FIELD ENGINEERING BULLETIN Pub. 523-K 28 NEW 8-7E Compliance Step Activity Yes No

1. Disconnect all power sources to the recombiner.

2. Remove wires numbered 310, 311, and 312 connecting L1, L2, and L3 to HS-10 (See drawing N116000121).

3. Connect facility 12AWG power wires 480 Vac 3-phase 60 Hz directly to JS-10, terminals L1, L2, and L3 Phase X, B, and C, respectively.

4. Add warning decal to bypass switch cover as follows:

CAUTION 480 VOLTS AC WARNING _

Disconnect switch bypassed; turn off facility ower to recombiner before opening this cabinet.

5. Install bypass jumpers to the following toggle switches in the valve operator starter cabinet (See drawing N116000121).

a. At switch HS-11 add jumper connecting wife 43 to 46 and wire 50 to 51.

b. At switch HS-12 add jumper connecting wire 48 to h

55 and wire 61 to 62.

c. At switch HS-13 id jumper connecting wife 65 to 96 and wire 11 t.o 72. .

6. Restore all power sources to recombiner systems.

Energize valves and verify proper valve direction tf

~

7.

rotation.

8. Perform complete periodic testing in accordance wi2 the l Operation and Maintenance Mar.ual.

t Approval :

i Quality Assurance Marager l

Changa 10. 3 - October 15, 1952 731-Z.229/arb

' D-10 1

?

_ .._-_..,..y . , , . _- ___ ._. . . _ _ ._- . . _ . .

N1160P31120002

,..;,ppsocx..iiiot;,o.,,o,c' TECHNICM SRWm E#iT db-6 -

n.,n s,....c,-, 3 '

"'

• 3 FIELD ENGINEER)NG BULLETIN aue s:2-o :e e. v. a m M  %

G ~D e m c:o I r C G! ! *.:]l.ft.

~

' Tr - T $T '

} 4N 9?

1 ~' e -

l Qih 5 -

-,$ ~

l D- .'>Q  ??

N  !

~ _

N $  !

., is:

lli e saa 9 c/  : 70o Oc, I e _ A~ T ~_t g W- ~

/ y ' ~' f

^l l m{ ~y- o,7>~=~>~- ,

i E  ?? P g a /"7 ' ' l t iI N e ~ _ 3

' a 4

m e e

. <? .

/

)

77? -l$2"[- dh 4  %

I e =

us ; f d wb4

% T;b h

R

%{'

\

-- rF D.Y.

N

• 7' s;;

l k Lk ..-

.l As g ,' l !l e e 6 t emW i I

-l lLals , . 2 .:.

"# N s

3 'Q c A 3[%

1}

.t?

> ru >.lI n,

[

gsMc i

~,

@l.R I,s.

1.

h.50l [ 1 o - , _ _

I r

< Ciange No. 3 - October 15,195 D-11/0-12

} :i 3~~% grsp:.ep 0 9 W + -

3b li ;7 1 Y -

N MM E N k i

_ . . - . . ._