Information Notice 1988-14, Potential Problems with Electrical Relays

Potential Problems with Electrical Relays

ML031150495
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, 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, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	04/18/1988
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-88-014, NUDOCS 8804110009
Download: ML031150495 (14)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 April 18, 1988 NRC INFORMATION NOTICE NO. 88-14: POTENTIAL PROBLEMS WITH ELECTRICAL RELAYS

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

This information notice is being provided to alert recipients to potential

problems involving HFA, PVD 218, PVD 21D, and HGA relays manufactured by

General Electric Company (GE), as described below. Although some of these

problems are several years old, they are included because utilities are still

identifying problems discovered while implementing advice issued by GE in the

early 1980s. The specific problem with the HFA relays concerns mechanical

binding in the relay caused by incorrect location of a stop tab that is welded

to the armature. The problems with the PVD 21B, PVD 21D, and HGA concern their

seismic capability. It is expected that licensees 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 do not constitute NRC requirements; therefore, no specific action or

written response is required.

Description of Circumstances

a. HFA Relays

In June 1986, Duane Arnold Energy Center reported that HFA relays were not

resetting. GE determined, after investigation, that mechanical binding in

the relays prevented the normally closed contacts from making contact when

the relays were de-energized. This was caused by the incorrect location

of a stop tab that is welded to the armature. The incorrect location, com- bined with possible movement of the magnetic assembly, causes the armature

binding. In July 1986, TVA experienced similar problems.

On July 21, 1986, the GE Meter and Control Business Division (MCBD),

Malvern, Pennsylvania, issued a 10 CFR Part 21 report to the NRC. On

November 14, 1986, MCBD issued Service Advice Letter (SAL) 188.1, which

.instructed recipients to test the relay to identify and correct improper

operation. The SAL stated that MCBD could not determine when the stop

tab problem had begun, but that relays manufactured between January 1983 and October 1986 were suspect. Date codes were provided that could be

IN 88-14 April 18, 1988 used to identify potentially affected relays. However, on June 5, 1987, Pilgrim implemented SAL 188.1 and identified several improperly operating

relays which were manufactured outside the suspected date codes.

In view of this, all HFA relays may be suspect. Additionally, the NRC

recently issued NRC Bulletin 88-03, "Inadequate Latch Engagement in

Type Latching Relays Manufactured by General Electric (GE) Company," HFA

March 10, 1988, regarding problems from inadequate latch engagement.

b. PVD 21B and PVD 21D Relays (see Attachment 1)

In 1977, GE listed the seismic capability of the normally open contacts

of

the PVD 21B and PYD 21D differential relays as 6g zero period acceleration

(ZPA) with the relay energized and the contacts closed. The tripping

each of these relays in response to differential over current is by of

a "low

set" voltage unit, device 87L, and a "high set" current unit, device 87H.

Device 87L is an instantaneous voltage unit that has its coil connected

across the dc terminals of a full wave rectifier device. Device 87L

has

two sets of normally open contacts, one of which is connected in parallel

with the contacts of the seal-in unit. Device 87H is an instantaneous

overcurrent unit, with its coil connected in series with thyrite discs;

it has a single set of normally open contacts.

Originally, GE published data which implied that the seismic capability

of 6g ZPA applied equally to both 87H and 87L functions. In 1983, GE

revised the seismic capabilities as follows: the capability of the

function remained at 6g ZPA, and the capability of the 87H function 87L

was

reduced to 2g ZPA. GE stated that the 87H set of normally open contacts

is generally wired in parallel with both the open 87L contacts and the

open 87L seal-in contacts when the PVD relay is used to trip a circuit

breaker. GE stated that the 87H function of the PVD is less sensitive

than the 87L function (it requires more operating signal). As a result, opening the normally open 87H contacts for a time greater than 2 milli- seconds as a consequence of a seismic event between 2g and 6g ZPA should

not interfere with tripping the circuit breaker because the parallel

contact would remain closed up to 6g ZPA. In view of the 2g ZPA seismic87L

capability of the 87H contact, GE recommended the application be checked

if the 87H contacts are used separately for any functions other than

tripping.

c. HGA Relays (see Attachment 1)

During a re-evaluation of qualification data for relays used in nuclear

Class IE systems, MCBD determined that the seismic data for HGA 11 and

HGA 111 relays published in MIL No. RS77-3, dated March 25, 1977, were

in error. The incorrect data were revised in MIL No. 82-12, dated

July 26, 1982. Specifically, MIL No. RS77-3 listed the seismic capa- bility of the normally closed contacts of ac-rated HGA 11 or HGA III

IN 88-14 April 18, 1988 relays at 1.Og ZPA when the relays were in the de-energized state. The

dc-rated relays were listed at 1.5g ZPA for the same condition. The re- vised seismic capability of the normally closed contacts of both ac and

dc HGA 11 and HGA 111 relays in the de-energized state is less than 0.5g

ZPA.

GE has conducted studies to determine design changes that could improve

the seismic capability of thie normally closed contacts when the relay is

de-energized. Additionally, a separate study considered the seismic capa- bility of alternate IGA relay models as a means for improving the seismic

capability of normally closed contacts with the relay de-energized. At

this time, GE has no plans for development of an HGA relay with improved

seismic capability.

On the basis of the above information, GE recommends that Class lE cir- cuits using normally closed contacts of HGA 11 and HGA 111 relays, with

the relay de-energized, be evaluated for the effect on the entire circuit

of an HGA 11 or HGA 111 contact opening long~r than 2 milliseconds.

On June 24, 1987, Duane Arnold reported to the NRC (1) that, based on the

revised data, HGA 11 relays providing critical functions in the core spray, low pressure coolant injection, high pressure coolant injection, and -

reactor core isolation cooling systems at Duane Arnold have indeterminate

qualification, and (2) that the relays were being replaced.

Discussion:

a. HFA Relays

For HFA relays, in addition to SAL 188.1, GE issued the following SALs:

(1) SAL 139.2, dated April 28, 1976. This SAL superseded SAL 139.1, dated September 5, 1973.

(2) SAL 152.1, dated April 28, 1976.

(3) SAL 152.2, dated November 3, 1980.

(4) SAL 152.2A, dated March 12, 1982.

(5) SAL 169.1, dated May ?8, 1982.

b. PYD 21 Relays

For PVD 21 relays, GE issued SAL 174.1 dated April 11, 1983. This SAL

provided clarification of the seismic capability of the 87H and 87L

contacts.

.r

IN 88-14 April 18, 1988 *

Most plants using PVD and HGA style relays are subject to the verification of

seismic adequacy of mechanical and electrical equipment under Unresolved Safety

Issue (USI) A-46 (as outlined in Generic Letter 87-02). However, PVD and HGA

style relays have also been found in newer plants that are not subject to

Generic Letter 87-02 (e.g., Susquehanna Unit 2 LER 86-024-000).

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

K.R. Naidu, NRR

(301) 492-0980

Attachments:

1. General Electric Letter to NRC

dated February 24, 1983

2. List of Recently Issued NRC Information Notices

Attachment 1 GENERAL * ELECTRIC ' POWER SYSTEMS

MANAGEMENT

BUIINESS

OENERAL ELECTRIC COMPANY. IN GRAT VALLEY PARKWAY, MALVERN PA 135513 DEPARTMENT

o (115) 251-7T00

"MO

February 24, 1983 Mr. Richard DeYoung

Director of Office of Inspection and Enforcement

United States Nuclear Regulatory Coumission

Washington, D.C. 20555 Dear Hr. DeYoung:

Attached is a copy of a letter relating to PVD21B and PYD 21D relays and

a copy of a letter relating to HGAlI and HGAlIl relays addressed to customers

we have knowledge of who may be applying these devices In nuclear

Installations.

It is our understanding that this fulfills our obligation to the Nuclear

Regulatory Cowission.

Yours truly, V Wa'nt

L. L. Hankoff

Manager-Engineering

LLM/gs

Attachment

cc: E. J. Flerko Malvern-1203 T. R. Macon Malvern-1205 M. J. Kirray Halvern-1206 V. Thomas NRC

-694039409 830224 PDR PT21 EMVGENE

83-758-000 PDR

.PYD21B and PYD21D SEISMIC CAPABILITY

During a re-evaluation of qualification data for relays used In nuclear IE

systems, some seismic data for PVD 21 relays published in MIL No. RS77-3, March 25, 1977 were found to be in error. The incorrect data were

subsequently revised In part In MIL No. 82-12, dated July 26, 1982. The

correct data for these relays are 6 9 ZPA for the 87L function and 2 9 ZPA for

the 87H function.

The normally open contacts of the PVD218 and PVD21D relays were listed In MIL

No. RS77-3 as having a 6 g ZPA capability when these contacts were closed with

the relay in the operate oode. During the period Decezber 19. 1980 through

April 27, 1981, a few Huclear Certification documents were Issued with a

revised value of 4 g ZPA. Certifications issued after April 27, 1981 through

January 17, 1983 listed the seismic Capability at 2 g U A. For-each of the

above cases, the seismic capability was implied to apply equally to the 87H

and 87L functions, the two tripping modes of the relay.

The seismic ceuability of the 87L function was correct at 6 9 VPA. The

seismic capability of the 87H function should have been listed as 2 g ZPA.

The 87H normally open contact is generally applied in parallel with the

normally open 87L contact and normally open 87L seal-in contact when the PVD

relay is used to trip a circuit breaker. The 87H function of the PYD is less

sensitive than the 87L function, (requires more operating signal), therefore

opening of the normally open 87H contact for a time greater than two

milliseconds as a consequence of a seismic event between 2 and 6 g ZPA, should

not interfere with tripping the circuit breaker because the parallel 67L

contact would remain closed up to 6 g ZPA.

If the 87H contact is used separately for any functions other than trip~ing, the application should be checked in view of the 2 g ZPA seismic capab iity of

the 87H contact.

HGAll and HGAlI SEISMIC CAPABILITY - NORMALLY CLOSED

CONTACT

S

During a re-e nluat10n-'ofqualfffeatfon data'for relays used In nuclear lE

systems, some seismic data for HGAlI and HGAlil relays published in NIL

No. RS77-3, March 25, 1977 were found to be in error. The incorrect data were

subsequently revised in NIL No. 82-12, dated July 26, 1982.

The normally closed contacts of AC rated HGAll or HGAltl rt;ays were listed

NIL No. RS77-3 as having a 1 9 ZPA seismic capability when the relays were Inin

the de-energized state. TheDC rated relays were listed

capability for the same condition.. A value of 0.3 9 ZPA as having 1.5 9 ZPA

should have been

listed for the normally closed contacts of both relays in the deenergized

state.

HGAlIl relays were recently re-tested for seismic capability and the values

obtained for normally closed contacts with the relay de-energ1ied were less

than the 0.5 g ZPA low limit of the test equipment..

Studies are underway to determine If there are design changes which could

increase the seismic capability of the normally closed contacts

is de-energized. In addition, a separate study will consider thewhen the relay

seismic

capabilities of alternate models of HGA relays as a means for Improving

seismic capability, of normally closed contacts with the relay de-energized.

Based on the preceding Information, It is reconnended that Class 1E circuits

using HGAtl or HGAlIl normally closed contacts with the relay de-energized

evaluated for effect on the entire circuit of an HGAll or HGAlIl contact be

opening exceeding two milliseconds duration.

Attachment 2 IN 88-14 April 18, 1988 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

88-13 Water Hammer and Possible 4/18/88 All holders of OLs

Piping Damage Caused by or CPs for nuclear

Misapplication of Kerotest power reactors.

Packless Metal Diaphragm

Globe Valves

88-12 Overgreasing of Electric 4/12/88 All holders of OLs

Motor Bearings or CPs for nuclear

power reactors.

88-11 Potential Loss of Motor -4/7/88 All holders of OLs

Control Center and/or or CPs for nuclear

Switchboard Function Due power reactors.

to Faulty Tie Bolts

88-10 Materials Licensees: Lack 3/28/88 All NRC licensees

of Management Controls Over authorized to use

Licensed Programs byproduct material.

87-44, Thimble Tube Thinning in 3/28/88 All holders of OLs

Supp. 1 Westinghouse Reactors or CPs for nuclear

power reactors that

employ a Westinghouse

NSSS.

88-09 Reduced Reliability of 3/18/88 All holders of OLs

Steam-Driven Auxiliary or CPs for nuclear

Feedwater Pumps Caused power reactors.

by Instability of Woodward

PG-PL Governors

88-08 Chemical Reactions with 3/14/88 All NRC licensees

Radioactive Waste generating or pro- Solidification Agents cessing low level

radioactive waste.

0

OL Operating License

CP = Construction Permit

1.

IN 88-14 April 18, 1988 Most plants using PVD and HGA style relays are subject to the verification of

seismic adequacy of mechanical and electrical equipment under Unresolved Safety

Issue (USI) A-46 (as outlined in Generic Letter 87-02). However, PVD and HGA

style relays have also been found in newer plants that are not subject to

Generic Letter 87-02 (e.g., Susquehanna Unit 2 LER 86-024-000).

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

K. R. Naidu, NRR

(301) 492-0980

Attachments:

1. General Electricc Letter to NRC

dated Februar3r 24, 1983

2. List of Recentl3f Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCES

• C/OGCB:DOEA:NRR *D/DRIS:NRR

CHBerlinger JGPartlow

0 88 U/11/88 03/15/88

• OGCB:DOEA:NRR*VIB:DRIS:NRR *SC/VIB:DRIS:NRR*A/BC/VIB:DRIS:NRR PPMB:ARM

BMann KNaidu EBaker JStone TechEd

02/23/88 02/23/88 02/24/88 02/24/88 03/11/88

IN 88-XX

April xx, 1988 Most plants using PYD and HGA style relays are subject to the verification of

seismic adequacy of mechanical and electrical equipment under Unresolved Safety

Issue (USI) A-46 (as outlined in Generic Letter 87-02). However, PVD and HGA

style relays have also been found in newer plants that are not subject to

Generic Letter 87-02 (e.g., Susquehanna Unit 2 LER 86-024-000).

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

K. R. Naidu, NRR

(301) 492-0980

Attachment: List of Recently Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCES

D/DOEA:NRR *C/OGCB:DOEA:NRR *D/DRIS:NRR

CERossi CHBerlinger JGPartlow

04/ /88 03/11/88 03/15/88

• OGCB:DOEA:NRR*VIB:DRIS:NRR *SC/VIB:DRIS:NRR*A/BC/VIB:DRIS:NRR PPMB:ARM

BMann KNaidu EBaker JStone TechEd

02/23/88 02/23/88 02/24/88 02/24/88 03/11/88

IN 88-XX

March xx, 1988 HGA style relays are subject to the verification of seismic adequacy of mechan- ical and electrical equipment under Unresolved Safety Issue (USI) A-46 (as

outlined in Generic Letter 87-02). However, PVD and HGA style relays have also

been found in newer plants that are not subject to Generic Letter 87-02 (e.g.,

Susquehanna Unit 2 LER 86-024-000).

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

K. R. Naldu, NRR

(301) 492-9659 Attachment: List of Recently Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCES

D/DOEA:NRR *C/OGCB:OWEA:NR NRR

CERossi CHBerlinger Partlow

03/ /88 03/11/88 03//S /88

• OGCB:DOEA:NRR*VIB:DRIS:NRR *SC/VIB:DRIS:NRR*A/BC/VIB:DRIS NRR PPMB:ARM

BMann KNaidu EBaker JStone TechEd

02/23/88 02/23/88 02/24/88 02/24/88 03/11/88

K>

IN 88-XX

March xx, 1988 HGA style relays are subject to the verification of seismic adequacy of mechan- ical and electrical equipment under Unresolved Safety Issue (USI) A-46 (as

outlined in Generic Letter 87-02). However, PYD and HGA style relays have also

been found in newer plants that are not subject to Generic Letter 87-02 (e.g.,

Susquehanna Unit 2 LER 86-024-000).

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

K. R. Naidu, NRR

(301) 492-9659 Attachment: List of Recently Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCES 0h5 JA/4/8 D/DOEA:NRR *C/OGCB:DOEA:NRR

CERossi CHBerlinger

02/ /88 02/29/88

• OGCB:DOEA:NRR*VIB:DRIS:NRR *SC/VIB:DRIS:NRR*A/BC/VIB:DRIS:NRR PPMB:ARM

BMann KNaidu EBaker JStone TechEd i

02/23/88 02/23/88 02/24/88 02/24/88 o0/11/88

IN 88-XX

February xx, 1988 HGA style relays are subject to the verification of seismic adequacy of mechan- ical and electrical equipment under Unresolved Safety Issue (USI) A-46 (as

outlined in Generic Letter 87-02). However, PVD and HGA style relays have also

been found in newer plants which are not subject to Generic Letter 87-02, (e.g., Susquehanna Unit 2 LER 86-024-000).

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

K. R. Naidu, NRR

(301) 492-9659 Attachment: List of Recently Issued NRC Information Notices

• SEE PREVIOUS CONCURRENCES

D/DOEA:NRR C

C/O D:0 NRR

CERossi CHBerlinger

02/ /88 02/19/88

• OGCB:DOEA:NRVX RIS:NRR SC/VIB:DRIS:NRR *A/BC/VI tDRIS:NRR PPMB:ARM

BMann 93K. KNaidu EBaker JStone % TechEd

02/23/88 02/23/88 02/24/88 02/24/88 02/ /88

IN 88-XX

February xx, 1988 HGA style relays are subject to the verification of seismic adequacy of mechan- ical and electrical equipment under Unresolved Safety Issue ((USI) A-46 (as Issue.

outlined in Generic Letter 87-02). However, PVD and HGA style relays have also

been found in newer plants which are not subject to Generic Letter 87-02, (e.g., Susquehanna Unit 2 LER 86-024-000).

No specific action or written response is required by thisA.ion Ratien_4n*t4ee.

If you have any questions about this matter, please contact the technical

contact listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

K. R. Naidu, NRR

(301) 492-9659 Attachment: List of Recently Issued NRC Information Notices

D/DOEA:NRR C/OGCB:DOEA:NRR

CERossi CHBerlinger

02/ /88 02/ /88 OGCB:DOEA:NRR VIB: ~% NRR SC RIS:NRR A/BC/VIB:DRIS:NRR PPMB:ARM

BMann SjIi KNai l EBak JStone TechEd

02/19/88 02/30288 D2/*48 02@4 /88 02/ /88

9,.6p-'

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