United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9903110112


INTEGRATED RESOURCES, INC.
Director, Office of Nuclear Material Safety and Safeguards
U. S. Nuclear Regulatory Commission
Washington, DC 20555
February 26, 1999

Dear Sirs:

On January 22, 1999 Integrated Resources, Inc. made a 10CFR Part 21 Notification Number 35304 to the U. S. Nuclear Regulatory Commission reporting the fact that there is a potential that Sprague Model TE1302 capacitors with a date code of 9322H were installed in some Safety Related instruments that were refurbished and repaired by Integrated Resources, Inc., and that the capacitors appeared to be failing prematurely. This letter and the attached report serves as the final analysis and report on this incident.

The failure has been determined to be a manufacturing defect and Integrated Resources, Inc., recommends that all of the affected capacitors be replaced.

If you should have any other questions concerning this notification or if we may be of any other service to you please contact me at 402-873-5859.

Sincerely,

John F. Brosemer
President
Integrated Resources, Inc.


IRI9901-01

P.O. BOX 310 - NEBRASKA CITY, NE 68410 - (402) 873-5859

INTEGRATED RESOURCES, INCORPORATED
TECHNICAL REPORT
COVER SHEET

IRI PROJECT NUMBER: IRI-9901
CLIENT PROJECT/P.O. NUMBER: VARIOUS
CLIENT: VARIOUS
PROJECT TITLE: 10 CFR 21 NOTIFICATION 35.304
DOCUMENT TITLE: TECHNICAL REPORT ON SPRAGUE MODEL TE1302 ALUMINUM ELECTROLYTIC CAPACITORS WITH A DATE CODE OF 9322H.
DOCUMENT TOTAL PAGES (INCLUDING COVER SHEET): 4
ORIGINATOR: DATE:
   


IRI JOB NO. IRI-9901 REPORT NO. IRI-9901-01 PAGE 2 OF 4

INTRODUCTION

This technical report is to provide final analysis and the root cause of the failures experienced due to aluminum electrolytic capacitors, Sprague Model TE1302 as reported to the Nuclear Regulatory Commission by Integrated Resources, Inc. as a 10 CPR Part 21 failure report number 35,304.

TECHNICAL REPORT AND FINDINGS

Dresden Nuclear Station advised IRI that they had experienced several failures of GEMAC Square Root Converters, Model Number 50-565100AAAC1, refurbished by IRI in 1993 and 1994. Dresden Nuclear Station returned 9 of the square root converters to IRI rogue. sting that failure analysis be performed on them. Of the 9 units two had been refurbished and calibrated when bench checked by IRI (Serial Numbers 16481447 and 334712442) , two additional units (serial numbers 334712437 and 524731551) had never been refurbished. These four units were refurbished, calibrated and returned to Dresden Nuclear Station.

The remaining square root converters (serial numbers 384724651, 394724607, 374724643, 334712437 and 374724641) were subjected to full component by component failure analysis. This analysis revealed that on all five of the units capacitor C1 had failed and was preventing the square root converters from meeting the calibration specifications satisfactorily.

All five of the capacitors removed from the modules were Sprague Electric Co. model TE1302 aluminum electrolytic capacitors with a value of 3 micro FD, 50 VDC, and a date code of manufacture of 9322H. These capacitors were manufactured for Sprague by Barker Microfarads, Inc., (BMI) of Hillsville, Virginia.

The loss of capacitance resulted in the Square Root Converters not being able to be calibrated to Original Equipment Manufacturers (OEM) Specifications. The square root converters did not fail but were not able to be calibrated and were, therefore, providing inaccurate outputs.

Preliminary testing of the capacitors was performed by IRI, showing that four of the five were open and the fifth had extremely high equivalent series resistance. IRI contacted Mr. Richard Edmonson, Quality Assurance Manager (Acting) of Barker Microfarads, Inc., and sent the failed capacitors to BMI for failure analysis. Having found that component failure had caused the square root converters to fail to calibrate, IRI issued a preliminary report to Dresden Nuclear Station of the results of the failure analysis and commenced searching instrument records to determine if any of the TE1302 capacitors with the 9322H date code had been used on any safety related units. This records search identified 96 separate refurbished units that contain the capacitors with a date code of 9322H, five of which were safety related, at two separate nuclear facilities, as follows:

1. Niagara Mohawk Power Corporation, Nine Mile point Unit #1
GEMAC Square Root Converter, model number 50-565100AAAC1, serial number 114624441.
GEMAC Function Generator, model number 50-566103ABAA2, serial number WP3283
2. New York Power Authority, J. A. Fitzpatrick Nuclear Station
GEMAC Basic Controller, model number 50-540017HAMM2PSY, serial number 203325049.
GEMAC Basic Controller, model number 50-540017HAMM2PSY, serial number WP1950.
GEMAC Basic Controller, model number 50-540017HAMM2PSY, serial number WP1949.

Having found that Nuclear Safety Related units had the capacitors installed IRI issued a verbal notification of the 10 CFR 21 report on January 22, 1999 at 1420 CST and was issued and incident number of 35,304. IRI also verbally notified Mr. M. Reno (NYPA) and W. Brian Barrett (NIMO) of the 10 CFR 21 report and the models and serial numbers of the units that the capacitors were insulted in.

Attachment 2, is the complete list (Nuclear Safety Related and Non-Nuclear Safety Related)of all units identified during the IRI records search that contain the 9322H date coded capacitors. IRI will transmit this list to each of the affected utilities, with this report, for all of the affected modules.

Failure analysis of the capacitors at BMI found that "...all of the parts were very dried out, and there was basically no electrolyte left. The seal bead dimension on all five parts measured 0.225". This is slightly larger than the current specification of 0.205 +/-0.008. Four of the five capacitors anode wire was broken internally, but it could not be determined what caused this failure. However, the fifth capacitor was not severed, but was still dried out. This is why we feel the root problem of the failures was the drying out of the capacitors."

(See Attachment 1 for the full letter from BMI).

CONCLUSION AND RECOMMENDATIONS

IRI has concluded that the Sprague model TE1302 capacitors with a date code of 9322H were manufactured with an end seat bead that was larger than specifications currently allow, the end seal allowed the capacitor's electrolyte to dry out (offgas) in an accelerated manner, causing the capacitors to fail in an accelerated manner. The failure mechanism of the capacitors are in the normal manner of all aluminum electrolytic capacitors, drying of the electrolyte which results in increasing equivalent series resistance (ESR) leading to increased heating of the electrolyte, leading to increased electrolyte drying, leading to increasing ESR, until the electrolyte is totally dried out and the capacitor fails.

IRI recommends that these capacitors be replaced as soon as practical. Since these capacitors have served over 60% of the expected shelf/useful life of the aluminum electrolytic capacitors IRI recommends that the modules that they are installed in be totally refurbished and all aluminum electrolytic capacitors in the modules replaced, during replacement of the affected capacitors.


REVISION NO. 0 ORIGINATOR INITIALS: DATE: 2/25/99

Attachment 1

BARKER MICROFARADS, INC. P.O. BOX 697, MILL STREET, HILLSVILLE, VIRGINIA 24343 FAX 540/728-9144 TEL 540/728-9121

January 28, 1999

Mr. John Brosemer
Integrated Resources
113 South 9th Street
P.O. Box 310
Nebraska City, NB 68410

Dear John:

In regards to the five capacitors that were returned for analysis, BMI has concluded that the parts were no longer within the acceptable parameters. The parts were all dated with the 9322 date code.

Failure analysis showed that all of the part were very dried out, and there was basically no electrolyte left. The seal bead dimension on all five parts measured 0.225". This is slightly larger than the current specification of 0.205" +/- 0.008". Four of the five capacitors anode wire was broken internally, but it could not be determined what caused this failure. However, the fifth capacitor (S/N 334712437) was not severed, but still was dried out. This is why we feel the root problem of the failures was the drying out of the capacitors.

As we discussed on the telephone, BMI had not received a field failure complaint for this reason to date. In addition, due to the nature of your application BMI will that you replace the capacitors in all the field parts. BMI will supply you with new capacitors that are sealed to the currently specified dimensions, which should prevent this problem from occurring again.

If you have any further questions or need more information, feel free to contact me anytime. We will try to assist you in every possible way. Thank you for your patience in this matter.

Sincerely,

Isaac K. Murrell
Engineering Manager

cc: Richard Edmondson
Tony Beamer
Ralph Poole


Attachment 2: "UNITS CONTAINING TE1302 CAPACITORS WITH 9322H DATE CODE"





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