Information Notice 1997-12, Potential Armature Binding in General Electric Type Hga Relays

Potential Armature Binding in General Electric Type Hga Relays
	ML031050360
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	03/24/1997
From:	Martin T; Office of Nuclear Reactor Regulation
To:	;
References
	IN-97-012, NUDOCS 9703200229
	Download: ML031050360 (10)
	v • d • e

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 March 24, 1997 NRC INFORMATION NOTICE 97-12: POTENTIAL ARMATURE BINDING IN GENERAL

ELECTRIC TYPE HGA RELAYS

Addressees

All holders of operating licenses or construction permits for nuclear power reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert

addressees that two General Electric (GE) type HGA relays failed to reposition when the coils

were deeneivizea. It is expected that recipients will review this information for applicability to

their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements; therefore, no

specific action or written response is required.

DescriDtion of Circumstances

On May 15, 1996, Commonwealth Edison Company (ComEd) reported that two 12HGA1 7S63 relays installed in the reset logic for the primary containment isolation system at its Dresden

Nuclear Power Station, Unit 3, failed to reposition when operators removed power to the

relay coils. The relay failures resulted in a failure to seal in isolation signals to a main steam

isolation valve and a recirculation sample isolation valve when operators reset a scram signal

after a reactor scram. Consequently, the valves opened when the scram was reset.

Operators used the manual switches in the control room to reclose the valves. ComEd

personnel removed the relays and disassembled them in an attempt to determine the root

cause of the problem. When a root cause could not be determined, the failed relays were

sent to GE Power Management (GE PM), located in Malvem, Pennsylvania, for a thorough

investigation.

Discussion

GE PM reassembled the failed relay submitted by ComEd for a root cause analysis and it

operated properly, both mechanically and electrically. When GE PM performed a

dimensional analysis of the critical parts, however, the assembly hole of the molded contact

support was found to be slightly off-center. GE PM stated that the mold that produces the

contact support was reworked in 1990 to correct for mold wear and to bring the parts within

the design drawing tolerances.

PDR T -E NoTICAE?-2-0/2 97O523Z

IN 97-12 March 24, 1997 GE PM issued Relay Service Advice Letter 516.1 on October 25, 1996, to alert customers

that HGA relays manufactured between January 1989 and June 1991 may have marginal

armature-to-contact support clearance and may be susceptible to armature binding.

However, some licensees may have procured the relays as commercial-grade, or received

them as basic components from a dedicating entity and, therefore, may not have received the

attached GE relay service advice letter. Consequently, some licensees may not have had

the opportunity to evaluate the information in accordance with 10 CFR Part 21.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts

listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Thomas . Martin, Director

Division of Reactor Pro-ram Management

Office of Nuclear Reactor Regulation

Technical contacts: K. Naidu, NRR

(301) 415-2980

E-mail: km@nrc.gov

S. Alexander, NRR

(301) 415-2995 E-mail: sda@nrc.gov

D. Skeen, NRR

(301) 415-1174 E-mail: dls@nrc.gov

Attachments:

1. GE Relay Service Advice Letter 516.1 dated October 25, 1996

2. List of Recently Issued NRC Information Notices

F> 1A( S 4

SENT BY:GE %URKETING/XALVEk, 2 ;12- 2-96 ;10:12AM ; GENEIRAL ELECTRIC- Attachment

1 IN 97-12 MULTIUN March 24, 1997 GE Power Management

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2O C 9dIVrVaget wr At-er

vrr. PA 13j55. 331 RELAY SERVIC ADVIC LETTER

Subject: HGA Armature Binding Number 516.1 Issued by- Customer Ser.ice DaNte: I025/96 Prepared by: Peter A Kotos

There has beme a report of incoMet operation of an HGA17S63 relay (date code: December,

1989). The relay had been continuously energized and failed to provide correct contact operation

when de-na ed. It was reported that the relay armature was not moving firely, it was

mechanically binding at the hinge area

The rCly was returned for examination. We examined the relay and were not able to reproduce

the bning condition that was reported. (TIe relay was returned disassembled. When assembled

the relay operated properly electrically and mechanicaly).

However, a dimensional analysis of the most critical parts dcted that the molded contact

support was slightly out of tolerance. Specifically, the assemblyrhole of the contact support was

slightly off center.

It is conceivable that this ofset cnbined with the manufacturing tolerances of the armature and

anet frame, possible foreign matter in the hnge ar and maybe excessive side pressure applied

to the con=at support when aembled could caie ftiction between the contact support and

magnetic finve resulting in armature binding.

According to our MS actung Engineering the mold that produces the cont support was

reworked in 1990 to correct for mold wear and bring the part weln within the drawing tolerances.

Currenty produced contact supports were checked and are well within the drawing tolerances

and do not produce armature binding.

Based on the field report, it is assumed that some HGA's may have been ipped with a mrinal

condition of armature clearance until this condition was noted by Quality Control and the mold

was corrected.

SENT BY:GE V1RXETING/N'ALVERKN ;12- 2-96 ;10:13.W GEN RLU ELECTRIC- 301 415 2968;; 3. 4

~ Attachment 1 IN 97-12 March 24, 1997 Page 2 SA #516.1 10/25/96 Although it isnot possible to determine exactly when the possible problem began, itis estimated

that relays manufactured between January, 1989, and June, 1991, (Dare Codes: ND. OD, PD,

RD. SD, M, UTD, VID, WD, XI, YD, ZD, NE, OE, PE, RE, SE, TE, UE, VE, WE, XE, YE,

ZE, NT, OF, P., RF, SF, AND TF) are suspect and may be checked for armature binding as

follows:

1. Do-energize the relay, coil and contacts.

2. Close the armature filly by hand, (push amature against the pole, see Fig. 1), and

gradually release. For corret operation, the armature should move to the filly open

position with no binding and with correct contact action. The normally open contacts

should open and the normally closed conta.ts should dose. If binding is detected, we

recommend the foliowing:

For "Nuclear IE" Applications: Contact General Electric Nuclear Energy Division

Customer Srvice Hotline: 1-800-425-8108 and refer to Service Advice No. S16.1.

For "Non - IE: Appkations: A replacement contact support is recommended.

Replacement contact supports (Par Number 006118683Pl) are available on a no-charge basis

and should be ordered through your local GE district Sales Office. Requests for the contact

supports must inc!ude:

A. AreferencetoServiceAdviccNo. 516.1 B. Date codes of the relays for which the replaement contact supports will be used.

Installation of Le contact support may be accomuplished by following the steps outied in

Attachment A.

Replacement contact supports will be available through November 1, 1997.

Labor for installation of the contact support or relay are the responsbility of the purchaser.

GENERAL ELECTRIC - 301 415 2968;; 4/ 4 SENT BY:GE XRKETING/MALVERN ;12- 2-96 ;10:14.0 ;

Attachment 1 IN 97-12 March 24, 1997 ATTACHMENT A - SA #516.1 The contact support should be replaced as follows: (Refer to Fig. 1)

IA Disengage the control spring from the armature end. (Note the groove location of

the spring hook on the armature).

2. Remove the assembly screw with its lockwasher.

3. Remove the nameplate and spring housing assembly.

4. Remove the moving contacts from the contact support and note their location for

correct reassembly.

S. Remove the contact support.

6. Install the new contact support. Make sure the armature is seated properly in the

contact support

7. Locate the moving contacts in the contact support.

8. Initail the nameplate and spring housing assembly.

9. Tighten the assembly screw and lockwasber (16 in-lbs. approx). Hold contact

support and spring housing assembly together while tightening assembly screw.

10. Engage the control spring on the same groove on the armature of the relay.

11. Operate the armature of the relay by hand to make sure that there is no binding.

12. Electrically check, and adjust if needed, the pickup of the relay in accordance with

instructions given ini the Instruction Book of the particular relay model number.

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Attachment 2 IN 97-12 March 24, 1997 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

92-27, Thermally Induced 03/21/97 All holders of OLs

Supp. 1 Accelerated Aging or CPs for nuclear

and Failure of ITE/ power reactors

Gould A.C. Relays

Used in Safety-Related

Applications

97-11 Cement Erosion from 03/21/97 All holders of OLs

Containment Subfounda- or CPs 'Jr nuclear

tions at Nuclear Power power reactors

Plants

97-10 Liner Plate Corrosion 03/13/97 All holders of OLs

in Concrete Containments or CPs for power

reactors

97-09 Inadequate Main Steam 03/12/97 All holders of OLs

Safety Valve (MSSV) or CPs for nuclear

Setpoints and Perform- power reactors

ance Issues Associated

with Long MSSV Inlet

Piping

97-08 Potential Failures 03/12/97 All holders of OLs

for General Electric or CPs for nuclear

Magne-Blast Circuit power reactors

Breaker Subcomponents

97-07 Problems Identified 03/06/97 All holders of OLs

During Generic Letter or CPs for nuclear

89-10 Closeout power reactors

Inspections

OL = Operating License

CP = Construction Permit

BIN K> 97-12 March 24, 1997 GE PM issued Relay Service Advice Letter 516.1 on October 25, 1996, to alert customers