LD-93-177, Part 21 Rept Re Potter & Brumfield motor-driven Relays Models 7032,7033 & 7034 Supplied by ABB/C-E to Entergy Operations Waterford Steam Electric Station,Unit 3.Eighty- Two Percent of Affected Relays Tested

Part 21 Rept Re Potter & Brumfield motor-driven Relays Models 7032,7033 & 7034 Supplied by ABB/C-E to Entergy Operations Waterford Steam Electric Station,Unit 3.Eighty- Two Percent of Affected Relays Tested

ML20059E237
Person / Time
Site:	Waterford
Issue date:	12/23/1993
From:	Toelle S ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY, ASEA BROWN BOVERI, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-93 LD-93-177, NUDOCS 9401110047
Download: ML20059E237 (5)

Text

l

. MEDER December 23, 1993 LD-93-177 Document Control Desk '

U.S. Nuclear Regulatory Commission Washington, D. C. 20555  ;

Subject:

10 CFR Part 21 Report on Potter & Brumfield MDR Model 7032, 7033, and 7034 Relays

References:

1) Letter LD-93-003, S. A. Toelle (ABB-CE) to Document Control Desk (NRC), "10 CFR Part 21 Report on Potter & Brumfield MDR Model 170-1, 7032, 7033, and 7034 Relays," January 13, 1993.

2) ABB Combustion Engineering TechNote No. 92-05,

" Potter and Brumfield MDR-Series Relay Deficiencies," September 4, 1992.

Dear Sir:

Pursuant to the requirements of 10 CFR Part 21, the purpose of this- '

letter is to notify the Nuclear Regulatory Commission of a. defect in motor-driven relays (MDRs) supplied by ABB Combustion Engineering (ABB-CE) to Entergy Operation's Waterford Steam Electric Station, Unit 3.

On November 19, 1993, Potter & Brumfield received eight relays from the Waterford Steam Electrle Station Unit 3 (WSES-3) for rework to replace potentially defective springs. The eight relays were spares that had not been in service. The issue of defective .

springs was previously addressed by Reference 1.

Upon receipt inspection by Potter & Brumfield, it was noted that  ;

seven of the eight relays had out-of-specification end-play of the shafts which was determined to be caused by oversized coils. In ,

mid-1992, ABB-CE identified oversized coils during the commercial grade dedication process of a batch of relays ordered by ABB-CE for WSES-3. All relays were returned to Potter & Brumfield by ABB-CE for rework and 100% inspection for proper coil size prior to delivery to WSES-3. On September 4, 1992, ABB-CE issued Reference 2 to inform ABB-CE NSSS owners of our findings. -

Notwithstanding this effort, Potter & Brumfield notified ABB-CE on '

December 3, 1993, that the coil size during the 1992 rework was-gauged to the wrong specification resulting in use of coils which  ;

were too large, which, in turn, resulted in insufficient end-play ,

of the shaft. Potter & Brumfield has also indicated that end-play ABB Lumbustion Engineering Nuclear Power Conteston Enyneenng. inc P O Fox Mo Telepare GJ3t fa8a911 1000 Pupoct H5 Rd Fax CO3) 06M203 .

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U.S. Nuclear Regulatory Commission LD-93-177 December 23, 1993 Page 2 4

l of relays which are in service with similarly out-of-specification coils would be expected to be worse due to temperature effects.

The relay construction is such that an oversized, epoxy-coated coil can " cold flow" or settle by a finite amount after manufacturing

.due to pressure and/or temperature effects. Potter & Brumfield has l advised ABB-CE that the rate of cold flow will be greatest j initially and is expected to reach a point within six months at i which no further cold flow compression will occur. Insufficient i end-play can cause the relay to bind and not actuate. The relays subject to the described failure mechanism are Potter & Brumfield ,

MDR relays, models 7032, 7033, and 7034, with date codes between '

9239 (the 39th week of 1992) and 9349. ABB-CE provided 83 relays from this specific lot to WSES-3 and 74 of them were installed during Refuel 5. These relays are used to actuate engineered )

safety features in the Engineered Safety Features Actuation System, and binding of these relays could prevent actuation of an  ;

engineered safety i'eature.

In-service measurement of relay end-play is not possible due to the relay mounting and wiring configuration. Eighty-two percent of the affected installed 7000-series relays at WSES-3 are presently tested on a 62-day frequency. Those relays have been tested multiple times during the fourteen months since Refuel 5 without any failures. Surveillance should preclude the need for ,

replacement of potentially defective relays at WSES-3 prior to the '

next scheduled outage in March 1994. It is our understanding that all affected relays will be removed from service at that time and returned to Potter & Brumfield for coil inspection and repair as {

necessary. Concurrent with this report, ABB-CE is preparing a i Combustion Engineering Infobulletin for distribution to all ABB-CE NSSS plants describing this situation.

The enclosure summarizes the information available to us at this time. If you have any questions, please contact me at (203) 285-5213.

Very truly yours, S. A. l S. A. Toelle Manager Nuclear Licensing .

1 1

11j/1w '

Enclosure:

As Stated t

Enclosure to LD-93-177 Page 1 of 3 (i) Name and address of the individual or individuals informing the commission.

Steven A. Toelle Manager, Nuclear Licensing ABB Combustion Engineering Nuclear Operations 1000 Prospect Hill Road Windsor, CT 06095 (ii) Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect.

Potter & Brumfield MDR relays, models 7032, 7033, and 7034 with date codes between 9239 (the 39th week of 1992) and 9349, used to actuate engineered safety features in the Engineered Safety Features Actuation System.

(iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.

ABB-CE purchased the subject component from:

Potter & Brumfield Inc.

200 S. Richland Creek Dr.

Princeton, Indiana 47671-0001 (iv) Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect '

or failure to comply.

On November 19, 1993, Potter & Brumfield received eight l relays from the Waterford Steam Electric Station Unit 3 l (WSES-3) for rework to replace potentially defective springs. The eight relays were spares that had not been l in service. The issue of defective springs was previously i addressed by ABB-CE's "10 CFR Part 21 Report on Potter &

Brumfield MDR Model 170-1, 7032, 7033, and 7034 Relays,"

LD-93-003, dated January 13, 1993.

Upon receipt inspection by Potter & Brumfield, it was noted that seven of the eight relays had out-of-specification end-play of the shaf ts which was determined to be caused by oversized coils. In mid-1992, ABB-CE identified oversized coils during the commercial grade

~

/ Enclosure to LD-93-177 Page 2 of 3 dedication process of a batch of relays ordered by ABB-CE for WSES-3. All relays were returned to Potter &

Brumfield by ABB-CE for rework and 100% inspection for i proper coil size prior to delivery to WSES-3. On ~

September 4, 1992, ABB-CE issued Combustion Engineering TechNote No. 92-05, " Potter and Brumfield MDR-Series Relay Deficiencies," to inform ABB-CE NSSS owners of our findings.

Notwithstanding this effort, Potter & Brumfield notified ABB-CE on December 3, 1993, that the coil size during the 1992 rework was gauged to the wrong specification resulting in use of coils which were too large, which, in turn, resulted in insuf ficient end-play of the shaf t. The incorrect specification used for maximum coil size was Top: 0.608 inches, Bottom: 0.798 inches. The correct specification should have been Top: 0.737 inches, Bottom:

0.678 inches. Potter & Brumfield has also indicated that end-play of relays which are in service with similarly out-of-specification coils would be expected to be worse due to temperature effects. The relay construction is such that an oversized, epoxy-coated coil can " cold flow" or settle by a finite amount after manufacturing due to pressure and/or temperature effects. Potter & Brumfield has advised ABB-CE that the rate of cold flow will be greatest initially and is expected to reach a point withir.

six months at which no further cold flow compression will occur. Insufficient end-play can cause the relay to bind and not actuate. The relays subject to the described failure mechanism are Potter & Brumfield MDR relays, models 7032, 7033, and 7034 with date codes between 9239 and 9349. These relays are to actuate engineered safety features in the Engineered Safety Features Actuation System, and binding of these relays- could prevent actuation of an engineered safety feature.

(v) The date on which the information of such defect or I failure to comply was obtained.

Initial ABB-CE determination: December 7, 1993.

(vi) In the case of a basic component which contains a defect or fails to comply, the-number and location of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulations in this part.

Enclosure to LD-93-177 Page 3 of 3 ABB-CE provided 83 relays from the subject lot to WSES-3 for use in their Engineered Safety Features Actuation Auxiliary Relay Cabinet; sixteen model 7032, fourteen model 7033, and fifty-three model 7034. It is our understanding that 74 of the 83 relays were installed during Refuel 5. ABB-CE also provided Potter & Brumfield model MDR 7032, 7033, and 7034 relays with earlier date codes as part of the original equipment for the Engineered Safety Features Actuation System to ANO Unit 2, SONGS Units 2 and 3, and Palo Verde Units 1, 2, and 3.

(vii) The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action.

In-service measurement of relay end-play is not possible due to the relay mounting and wiring configuration.

Eighty-two percent of the affected installed 7000-series relays at WSES-3 are presently tested on a 62-day -

frequency. Those relays have been tested multiple times during the fourteen months since Refuel 5 without any failures. The remaining 18% are tested on an 18-month frequency. Surveillance should preclude the need for replacement of potentially defective relays at WSES-3 prior to the next scheduled outage in March 1994. It is our understanding that all af fected relays will be removed from service at that time and returned to Potter &

Brumfield for coil inspection and repair as necessary.

(viii) Any advise related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees. .

ABB-CE, concurrent with this Part 21 report, is preparing a Combustion Engineering Infobulletin for distribution to >

all ABB-CE NSSS plants. This Infobulletin will recommend that potentially affected utilities determine if relays from the subject lot were procured directly from Potter &

Brumfield or from other suppliers of Potter & Brumfield relays. It is our understanding that Potter & Brumfield is preparing a notice to issue to potentially affected customers advising them of this situation.

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