Information Notice 1988-27, Deficient Electrical Terminations Identified in Safety-Related Components

Deficient Electrical Terminations Identified in Safety-Related Components

ML031150157
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, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	05/18/1988
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-88-027, NUDOCS 8805120108
Download: ML031150157 (11)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 May 18, 1988 NRC INFORMATION NOTICE NO. 88-27: DEFICIENT ELECTRICAL TERMINATIONS

IDENTIFIED IN SAFETY-RELATED COMPONENTS

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

This information notice is being provided to alert addressees of deficiencies

identified in electrical terminations in safety-related components. It is ex- pected that recipients will review the 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

The Nuclear Regulatory Commission (NRC) has been notified of several recently

identified deficiencies in electrical terminations in safety-related components

that, if they had remained uncorrected, would have jeopardized the ability of

these components to perform their intended safety function. These deficiencies

were identified at River Bend Station, Unit 1; Shoreham Nuclear Power Station;

Vermont Yankee Nuclear Power Station; and Oyster Creek, Unit 1.

River Bend Station, Unit 1

On January 19, 1988, the Gulf States Utility Company (GSU) submitted a notifica- tion to the NRC, pursuant to 10 CFR Part ?1, regarding oversized motor operator

termination lugs in three main steam shutoff valves and two feedwater isolation

valves. GSU reported that during functional testina of a main steam shutoff

valve on December 7, 1987, the valve motor operator experienced a high current

surge, which tripped its motor overload heater and prevented the valve from

fully closing. During GSU's investigation, two motor leads were found burned

and separated from the lugs. A third lug was easily pulled from the motor lead

by GSU personnel after they removed the heat shrink insulation. The lugs were

found to be oversized for the motor lead conductors. In addition, during mainte- nance on a feedwater isolation valve, a lug on one motor lead was found to be

8852C at

IN 88-27 May 18, 1988 oversized for the conductor and not crimped. These lugs were manufactured by

Thomas & Betts. They were marked "T&B Navy 23-30 E-611 and were sized for use

with a #5-#6 AWG conductor. The actual motor leads were #10 AWG stranded

conductors.

Further investigation by GSU personnel found that both valves used Llmitorque

SMB-4 motor operators with terminal blocks that had one-ouarter-inch diameter

terminal screws. The lugs were the correct size for the one-quarter-inch screw, but not for the conductor. All SMB-4 operators used in safety-related applica- tions were inspected by the licensee to determine lug size. Ten SMB-4 operators

were inspected, and five were found with oversized lugs that were deemed unre- liable by the licensee, although they passed their surveillance requirements.

GSU personnel replaced the defective lugs with correctly sized lugs. GSU is

also revising its procedures for inspecting Limitorque motor operators when they

are received to include inspection of lug size on the motor leads to prevent re- currence of this condition, since the defective wire lugs were contained in valve

operators supplied by the Limitorque Corporation during the construction of River

Bend Station.

In a separate 10 CFR Part 21 notification dated December 23, 1987, GSU reported

that several defective terminations were identified in electrical heater panels

supplied by NUTHERM International, Inc. The defective wire terminations were

in heater panel circuits of the fuel storage building engineered safety feature

charcoal filters. The deficiency involved improper stripping of conductors that

resulted in insulation under the termination lugs. This insulation inhibited a

good connection and Jeopardized the ability of the filters to perform their

function. GSU reported that it had notified NUTHERM International of the defect.

Shoreham Nuclear Power Station

On October 19, 1987, the Long Island Lighting Company (LILCO) submitted a

notification to the NRC pursuant to 10 CFR Part 21 regarding inadequately

crimped termination lugs discovered at the Shoreham Nuclear Power Station.

The subject lugs, which were manufactured by AMP Special Industries, were

installed in control wiring in 4160-volt switchgear equipment manufactured

by the General Electric Company (GE). The licensee discovered that many of

the GE-installed termination lugs were inadequately crimped to the control

wires and, in some cases, the lugs could be removed by hand. When LILCO

personnel inspected these lugs in equipment supplied by GE, they found that

of approximately 1400 lugs installed by GE, 42% had to be replaced.

GE determined that its personnel had deviated from the crimp process described

in their installation procedures during the manufacture of the equipment. There- fore, the insulation around the control wires was not properly stripped before

beinq inserted into the AMP lugs and an AMP crimper was not used as required.

GE also determined that this problem was limited to equipment supplied to

IN 88-27 May 18, 1988 Shoreham and Salem. GE stated that it had notified both facilities of the

problem and that its personnel had been requalified on the proper crimping

procedures to preclude any further similar incidents.

Vermont Yankee Nuclear Power Station

On September 28, 1987, Vermont Yankee Nuclear Power Station (Vermont Yankee)

personnel were conducting pre-startup operability tests on the residual heat

removal (RHR) pumps and core spray pumps. During the operability tests, the

"B" RHR pump motor experienced severe arcing problems and was quickly secured, preventing damage to the motor windings.

Vermont Yankee personnel investigated the problem and found that the arcing

resulted from a failed AMP motor lead to power lead termination lug. Motor

lead and power lead termination lugs were subsequently Inspected on three other

RHR pumps and core spray pumps fitted with AMP lugs. Termination lugs manu- factured by Thomas & Betts (TABR that are used on RHR service water pumps and

station service water pumps also were inspected. These inspections identified

evidence of cracking of varying severity on seven AMP motor lead termination

lugs; however, no cracks were found on power lead terminations. Little or no

cracking was identified on terminations manufactured by T&B. The AMP motor

lead termination lugs were of the ring tongue type, #2 AWG, model #35184, manufactured by AMP Special Industries. The terminations were supplied in

conjunction with the motors by GE.

Several of the cracked lugs were discovered by direct visual inspection, while

the remainder were identified using IOX magnification and/or dye penetrant

testing. During inspection of the lugs, it appeared that the manufacturer's

stamping on the throat of the lug contributed to the observed cracking because

a shallow "AMP" die stamp was found at the throat section of the lug. A stamp

(a numeral 1, 2, or 3) on the opposite side of the throat, believed to be a

phase indication, was also suspected of being a contributor. The cracking

identified on these luqs was ultimately attributed to excessive bending during

maintenance activities, with the manufacturer's stamping providing pre-stressed

flaws for crack initiation and propagation. The small cramped work space inside

the motor terminal housings, coupled with the rigidity of the required Raychem

splices, contributed to fatiguing the lugs during maintenance activities.

Oyster Creek, Unit 1

GPU Nuclear Corporation (GPUNC) submitted Licensee Event Report (LER) 219-87-011, Revision 1, to the NRC on May 4, 1987, regarding deficient electrical terminations

at Oyster Creek, Unit 1. GPUNC reported that on February 10, 1987, an electrical

technician who was verifying proper wiring connections inadvertently moved a wiring

harness in a control room panel. This movement disconnected the "A" feedwater

flow rate signal wire and initiated a sequence of events that resulted in a

IN 88-27 May 18, 1988 turbine trip and an anticipatory scram. On February 26, 1987, an electrical

technician, performing an Inspection of wire terminations In response

previous event, disturbed a wire that caused the automatic closure to the

steam isolation valves. of the main

The GPUNC investigation determined that the cause of the first event

was in- sufficient procedural controls over wire termination practices. The

wire

terminations used in the control room panel were compression-type terminations, which capture wires under a metal plate compressed by a screw, rather

lug-type terminations. GPUNC personnel found that different size wiresthan

were

used in the same termination and that sometimes the plate in the compression

terminations was removed when wires were too large to fit under the

GPUNC investigation also found terminations with cracked or broken plate. The

pressure

plates, as well as wires that were unlabeled, unterminated, and uninsulated.

Furthermore, GPUNC personnel discovered that.when new cables were

support modification work, existifng wire terminations were stressedpulled to

by the new

wires that lay on top of the original wiring.

The second event was attributed to faulty wire installation, either

plant construction or during subsequent maintenance. Inspection of during

termination showed that the screw used to fasten the wire was loose. the wire

Movement

of this wire caused four relays to deenergize, resulting in automatic

closure

of the main steam isolation valves.

GPUNC personnel identified and corrected a total of 123 deficient terminations, both compression-type and lug-type. GPUNC has revised its Installation

fications for wire terminations and Quality Assurance Procedures for Speci- wire terminations to ensure and verify proper electrical terminations. inspecting

These

revisions will ensure that an adequate structural integrity of the termination

exists, require that a post-modification and maintenance tug test be

and eliminate the practice of terminating two wires with significant performed, differences in compression-type terminations unless it Is endorsed by cauqe

termination manufacturer. In addition, GPUNC Indicated that It was inthe

process of Identifying those terminations that are frequently accessed the

for

surveillance and maintenance purposes and will install test connections

minimize movement and stress on the terminations. to

Discussion:

These examples emphasize the need to carefully monitor the receipt, lation, and maintenance of safety-related components with respect to Instal- cable or wire terminations. Licensees may wish to review their current their

installation, and maintenance procedures to assure that proper ouality receipt, and measures exist to preclude such events as those discussed above. controls

IN 88-27 May 18, 1988 No specific action or written response is required by this information notice.

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

contacts 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

Technical Contacts: Jaime Guillen, NRP

(301) 492-1153 Carl S. Schulten, NRR

(301) 492-1192 Attachment: List of Recently Issued NRC Information Notices

Attachment

IN 88-27 May 18, 1988 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

85-35, Failure of Air Check 5/17/88 All holders of OLs

Supplement 1 Valves to Seat or CPs for nuclear

power reactors.

88-26 Falsified Pre-Employment 5/16/88 All holders of OLs

Screening Records or CPs for nuclear

power reactors and

all major fuel

facility licensees.

88-25 Minimum Edge Distance for 5/16/88 All holders of OLs

Expansion Anchor Rolts or CPs for nuclear

power reactors.

88-24 Failures of Air-Operated 5/13/88 All holders of OLs

Valves Affecting Safety- or CPs for nuclear

Related Systems power reactors.

88-23 Potential for Gas Binding 5/12/88 All holders of OLs

of High-Pressure Safety or CPs for PVWRs.

Injection Pumps During a

Loss-of-Coolant Accident

88-22 Disposal of Sludge from 5/12/88 All holders of OL.s

Onsite Sewage Treatment or CPs for nuclear

Facilities at Nuclear power reactors.

Power Stations

88-21 Inadvertent Criticality 5/9/88 All holders of OLs

Events at Oskarshamn or CPs for nuclear

and at U.S. Nuclear power reactors.

Power Plants

88-20 Unauthorized Individuals 5/5/88 All holders of OLs

Manipulating Controls and or CPs for nuclear

Performing Control Room power, test and

Activities research reactors, and all licensed

operators.

OL = Operating License

CP = Construction Permit

IN 88-27 May 18, 1988 No specific action or written response is required by this information noti ce.

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

contacts 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

Technical Contacts: Jaime Guillen, NRR

(301) 492-1153 Carl S. Schulten, NRR

(301) 492-1192 Attachment: List of Recently Issued NRC Information Notices

Initially transmitted by memorandum dated November 20, 1987, to C. H. Berlinger

from W. D. Lanning

• SEE PREVIOUS CONCURRENCES

05//V88

• C/OGCB:[OEA:NRR *PPMB:ARM *DRP:RI *D/DEST:NRR *SAD/DEST:NRR

CHBerlinger TechEd WFKane LCShao AThadani

05/10/88 02/29/88 03/ /88 04/13/88 04/12/88

• OGCB:DOEA:NRR *OEAB:DOEA:NRR*SC/OEAB:DOEA:NRR *C/EAB:DOEA: NRR*C/SELB:DEST:NRR

JGuillen CSchulten PWBaranowsky WDLanning FRosa

03/02/88 03/03/88 03/03/88 03/31/88 03/21/88

IN 88-XX

May xx, 1988 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

Jainme Guillen, NRR

(301) 492-1153 Carl S. Schulten, NRR

(301) 492-1192 Attachment: List of Recently Issued NRC Information Notices

Initially transmitted by memorandum dated November 20, 1987, to C. H. Berlinger

from W. D. Lanning

• SEE PREVIOUS CONCURRENCES

D/DOEA:NRR

CERossl

05/ /88 C /OGCB:DOEA:NRR *PPMB:ARM

CHBerlinger TechEd

• DRP:RI

WFKane

• D/DEST:NRR

LCShao

• SAD/DEST:NRR

AThadani

05/10/88 02/29/88 03/ /88 04/13/88 04/12/88

• OGCB:DOEA:NRR *OEAB:DOEA:NRR*SC/OEAB:DOEA:NRR *C/EAB:DOEA:NRR*C/SELB:DEST:NRR

JGuillen CSchulten PWBaranowsky WDLanning FRosa

03/02/88 03/03/88 03/03/88 03/31/88 03/21/88

IN 88-XX

March xx, 1988 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

Jaime Guillen, NRR

(301) 492-1153 Carl S. Schulten, NRR

(301) 492-1192 Attachment: List of Recently Issued NRC Information Notices

Initially transmitted by memorandum dated November 20, 1987, to C. H. Berlinger

from W. D. Lanning

• SEE PREVIOUS CONCURRENCES

D/DOEA:NRR

CERossi

03/ /88 C/OGCB:DOEA:NRR *PPMB:ARM DRI .:NRR

CHBerlinger TechEd WFKane

03/ /88 02/29/88 03/ /88 '

• OGCB:DOEA:NRR *OEAB:DOEA:NRR*SC/OEAB:DOEA:NRR

JGuillen CSchulten PWBaranowsky FRosa

03/02/88 03/03/88 03/03/88 03/21/88

IN 88-XX

March xx, 1988 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

Jaime Guillen, NRR

(301) 492-1153 Carl S. Schulten, NRR

(301) 492-1192 Attachment: List of Recently Issued NRC Information Notices

Initially transmitted by memorandum dated November 20, 1987, to C. H. Berlinger

from W. D. Lanning

• SEE PREVIOUS CONCURRENCES

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

CERossi CHBerlinger

03/ /88 4&03/4v/88 OG  : RR OEA P9E- :NRR *PPMB:ARM ^~ NRR C/SELB: OSwRR

JGui len Cs TechEd Piar~'ows ky FRosa V

03/X 88 03 5 /88 02/29/88 0313 /88 03/2#/88 DR :

WF ne

/ /88

IN 88-XX

February xx, 1988 No specific action or written response is required by this infonmation 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

Jaime Guillen, NRR

(301) 492-1153 Attachment: List of Recently Issued NRC Information Notices

Initially transmitted by memorandum dated November 20, 1987, to C. H. Berlinger

from W. D. Lanning

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

CERossi CHBerlinger

02/ /88 021 /88 OGCB:DOEA:NRR OEAB:DOEA:NRR PPMB:ARM C/SELB:DEST:NRR DRP:RI

JGuillen CSchulten TechEd 42? FRosa WFKane

02/ /88 02/ /88 02/a2/88 02/ /8F 02/ /88