United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9902190197


Coltec Industries Fairbanks Morse
Engine Division
701 White Avenue
Beloit, WI 53511-5492
http://www.fairbanksmorse.com [EXIT]
608/364-4411
Fax: 608/364-0382
 
February 15, 1999
Document Control Desk
U.S. Nuclear Regulatory Commission
Washington, DC 20555
File No. 99-601
Subject: Synchro-Start - ESSB-4AT Speed Switches, Model SA2110

On January 20, 1999, Coltec Industries, Fairbanks Engine Division (FMED), became aware of a potential safety hazard associated with the Synchro-Start - ESSB-4AT speed switches supplied to PSE&G - Hope Creek nuclear power station. FMED had supplied four Synchro-Start ESSB-4AT Model SA2110 speed switches to Hope Creek in late 1991 and early 1998, which malfunctioned after approximately 70 hours of energization, Hope Creek had previously evaluated the failures as not being a substantial safety hazard.

In the attached Engineering Report and root cause investigation, FMED evaluated the starting circuitry and confirms that this is not a substantial safety hazard at Hope Creek due to redundant circuitry. However, the investigation revealed that it is likely that one more ESSB- 4AT Model SA2110 speed switch manufactured by Synchro-Start may have been supplied to the nuclear industry or non-nuclear application by a supplier other than Coltec Industries. The list of possible recipients of the suspect speed switch are: Wolf Creek Nuclear, Engine Systems Inc, Florida Keys Electric, Interstate Power Company, Rolls Royce, and Traycanna. Therefore, notification is being made of the potential substantial safety hazard that might exist at other nuclear facilities that have purchased an ESSB-4AT Speed Switch in late 1997 and early 1998.

The Engineering Report also determined the root cause of the speed switch failures to be personnel error at Synchro-Start. A personnel error was made by picking the wrong current limiting resistor from stock for installation into the speed switch power supply circuit card. Corrective actions have been taken by Synchro-Start to prevent recurrence including moving the stock location of the resistors, retraining personnel, and changing procedures to verify proper resistor during bench testing.

Sincerely,

James C. Golding
Senior Quality Assurance Engineer

 
cc:
Terry Gill
Mary Armfield
Ted Stevenson
Greg Gutoski
Steve Greuel

A decision of Coltec Industries Inc.


Coltec Industries BF30108 PAGE NO. 1
 
 
ENGINEERING REPORT FILE NO. R-6.03.6071
Fairbanks Morse Engine Division DATE Feb 15, 1999
SUBJECT INVESTIGATION OF FAILED REPLACEMENT SPEED SWITCHES AT PSE&G HOPE CREEK NUCLEAR POWER STATION
PREPARED BY S Greuel
REPORT TITLE SYNCHRO-START ESSB-4AT SPEED SWITCHES, MODEL SA2110
APPROVED BY G Gutoski

This report documents the investigation into the reported failure of the above named speed switches. The investigation was conducted by personnel from Coltec representing quality assurance and engineering. The investigation culminated in a visit on Wednesday morning the 27th of January by the personnel from the NRC and by a visit by the same group the next day, to the Synchro-Start Corporation.

The investigation primarily focused on what ramifications the particular type of speed switch failure would have on the ability of the genset to perform its intended function. Because it was so readily apparent, the cause of the failure of the speed switches was a secondary concern. The determined seriousness of the failure warranted reporting under Part 21.

Part 21 99-001 identified the degradation of four speed switches manufactured by Synchro-Start; the speed switches were model ESSB-4AT, part # SA-2110. They were furnished to Hope Creek in late 1997 and early 1998 with Synchro-Start sales order numbers 79116 (quantity 3) and 81697 (quantity 1). Based on conversation with Mr. George Daves of Hope Creek, the degradation of each switch occurred within 30 to 70 hours after installation. The specific cause of the degradation was the installation of an incorrect resistor which resulted in overheating of the internal power supply regulating transistor. The degraded speed switches were all found to have an 82 ohm resistor in the internal power supply which is applicable for a 24 vdc external supply voltage. The correct value of resistor should have been 1200 ohms which is the correct value for the 125 vdc external supply that is used at Hope Creek.

Coltec Industries and the NRC visited Synchro-Start on 28 January, to further determine the cause of the failures. During the visit, it was shown that the cause of the incorrect resistor was due to personnel error in picking the wrong resistor from the location in the stock room with subsequent installation onto the internal power supply printed circuit board that is installed in the speed switch. Synchro-Start has taken corrective action to prevent recurrence by rearrangement of the resistor stocking, re-training of personnel, and further verification of the proper resistor during bench testing.

Synchro-Start was able to determine that five intenal power supply boards were improperly assembled. Four of those five power supply boards were supplied to Coltec in the speed switches referenced in FMED purchase orders referenced above. All four of these speed switches were dedicated and supplied to PSE&G Hope Creek. Synchro-Start has also determined that there may be one additional speed switch that has been supplied to one of the following customers in late 1997 or early 1998: Wolf Creek Nuclear, Engine Systems Inc, Florida Keys Electric, Interstate Power Company, Rolls Royce, or Traycana.


Coltec Industries BF30108 PAGE NO. 2
 
 
ENGINEERING REPORT FILE NO. R-6.03.6071
Fairbanks Morse Engine Division DATE Feb 15, 1999
SUBJECT INVESTIGATION OF FAILED REPLACEMENT SPEED SWITCHES AT PSE&G HOPE CREEK NUCLEAR POWER STATION
PREPARED BY S Greuel
REPORT TITLE SYNCHRO-START ESSB-4AT SPEED SWITCHES, MODEL SA2110
APPROVED BY G Gutoski

Based upon review of the diesel generator starting circuitry, where the switch is used, PSE&G Hope Creek is designed and constructed with both a speed switch and a jacket water pressure switch to effectively accomplish the same function. Either the speed switch or the jacket water pressure switch will actuate indicators, alarms, starting air, and the generator field-flash circuit. Therefore, degradation of the speed switch would not impact the ability of the diesel generator to start and deliver power when required.

While the degradation described in the Part 21 99-001 pertains only to PSE&G at Hope Creek and the ESSB 4AT speed switch, Coltec Engineering has also evaluated the applicability to other power stations that use a similar speed switch, such as models ESSB-2AT and -3AT, in a similar circuit arrangement. These other models of speed switch would also use the same internal power supply. Coltec identifies the power stations listed below. It should be noted that Hope Creek is the only installation that employs the ESSB-4AT for speed switch requirements. Coltec has not been notified of any other speed switch degradations at any of the other nuclear power stations; Hope Creek is the only instance.

Alabama Power--Farley
Entergy--Arkansas Nuclear One
Georgia Power--Hatch 1
Detroit Edison Fermi 2
Northeast Utilities Millstone 3
Public Service New Hampshire--Seabrook
Angra Brazil
Duquesne Light--Beaver Valley
SCE&G--V C Summer
PECO--Limerick
Union Electric--Callaway
Kansas Gas and Electric--Wolf Creek
PSE&G-Hope Creek

Coltec Engineering has also reviewed the starting circuitry for the above mentioned power stations. All of the above stations have the similar redundant starting circuitry found at Hope Creek with four exceptions. The four exceptions are Alabama Power, Detroit Edison, Northeast Utilities, and Angra Brazil. At these four plants, if the installed speed switch should fail, the diesel would then fail to start, because of the failed speed switch, and not perform its intended design function. At this time, there is no substantive safety hazard because none of these plants have received any suspect speed switches.


Coltec Industries BF30108 PAGE NO. 3
 
 
ENGINEERING REPORT FILE NO. R-6.03.6071
Fairbanks Morse Engine Division DATE Feb 15, 1999
SUBJECT INVESTIGATION OF FAILED REPLACEMENT SPEED SWITCHES AT PSE&G HOPE CREEK NUCLEAR POWER STATION
PREPARED BY S Greuel
REPORT TITLE SYNCHRO-START ESSB-4AT SPEED SWITCHES, MODEL SA2110
APPROVED BY G Gutoski

As an aside to the above, FMED Engineering Would be available to be retained to engineer design modifications to provide starting switch redundancy at these four sites if asked.

Therefore, this investigation and finding at Hope Creek is not considered a substantial safety hazard as defined by Part 21. This is due to the redundancy in the starting circuitry, However, since there may be one remaining speed switch With an improper internal power supply, there may be a safety hazard depending on the configuration of the starting circuitry and the incorporation of redundancy at that site.


02/15/1999 U.S. Nuclear Regulatory Commission Page 1
Operations Center Event Report
General Information or Other (PAR) Event# 35369
Rep Org: COLTEC INDUSTRIES Notification Date/Time: 02/15/1999 15:26 (EST)
Supplier: SYNCHRO-START CORPORATION Event Date/Time: 01/20/1999 (CST)
Last Modification: 02/15/1999
 
Region: 3 Docket #:
City: BELOIT Agreement State: No
County: License #:
State: WI
NRC Notified by: JAMES C. GOLDING Notifications: GARY SHEAR R3
HQ Ops Officer: LEIGH TROCINE LAURIE PELUSO R1
Emergency Class: NON EMERGENCY THOMAS DECKER R2
10 CFR Section: JOHN PELLET R4
21.21
UNSPECIFIED PARAGRAPH
VERN HODGE NRR
10-CFR-PART-21 NOTIFICATION FROM COLTEC INDUSTRIES, FAIRBANKS MORSE ENGINE DIVISION, REGARDING SYNCHRO-START -- ESSB-4AT SPEED SWITCHES, MODEL SA2110

The following text is a portion of a facsimile received from the Coltec Industries:

"On January 20, 1999, Coltec Industries, Fairbanks Engine Division (FMED), became aware of a potential safety hazard associated with the Synchro-Start -- ESSB-4AT speed switches supplied to PSE&G -- Hope Creek Nuclear Power Station. FMED had supplied four Synchro-Start ESSB-4AT Model-SA2110 speed switches to Hope Creek in late 1997 and early 1998, which malfunctioned after approximately 70 hours of energization. Hope Creek had previously evaluated the failures as not being a substantial safety hazard."

"In the ... root cause investigation, FMED evaluated the starting circuitry and confirms that this is not a substantial safety hazard at Hope Creek due to redundant circuitry. However, the investigation revealed that it is likely that one more ESSB-4AT Model-SA2110 speed switch manufactured by Synchro-Start may have been supplied to the nuclear industry or non-nuclear application by a supplier other than Coltec Industries. The list of possible recipients of the suspect speed switch are: Wolf Creek Nuclear, Engine Systems Inc, Florida Keys Electric, Interstate Power Company, Rolls Royce, and Traycanna. Therefore, notification is being made of the potential substantial safety hazard that might exist at other nuclear facilities that have purchased an ESSB-4AT speed switch in late 1997 and early 1998."

"The Engineering Report also determined the root cause of the speed switch failures to be personnel error at Synchro-Start. A personnel error was made by picking the wrong current limiting resistor from stock for installation into the speed switch power supply circuit card. Corrective actions have been taken by Synchro-Start to prevent recurrence including moving the stock location of the resistors, retraining personnel, and changing procedures to verify proper resistor during bench testing."

The Engineering Report from Coltec Industries also stated, "While the degradation described in the Part 21 ... pertains only to PSE&G at Hope Creek and the ESSB-4AT speed switch, Coltec Engineering has also evaluated the applicability to other power stations that use a similar speed switch, such as models ESSB-2AT and --3AT, in a similar circuit arrangement. These other models of speed switch would also use the same internal power supply.


02/15/1999 U.S. Nuclear Regulatory Commission Page 2
Operations Center Event Report
General Information or Other (PAR) Event# 35369

Coltec identifies the power stations listed below. It should be noted that Hope Creek is the only installation that employs the ESSB-4AT for speed switch requirements. Coltec has not been notified of any other speed switch degradations at any of the other nuclear power stations; Hope Creek is the only instance."

"Alabama Power--Farley
Entergy--Arkansas Nuclear One
Georgia Power--Hatch 1
Detroit Edison--Fermi 2
Northeast Utilities--Millstone 3
Public Service New Hampshire--Seabrook
Angra Brazil
Duquesne Light--Beaver Valley
SCE&G--V C Summer
PECO--Limerick
Union Electric-Callaway
Kansas Gas and Electric--Wolf Creek
PSE&G--Hope Creek"

"Coltec Engineering has also reviewed the starting circuitry for the above mentioned power stations. All of the above stations have the similar redundant starting circuitry found at Hope Creek with four exceptions. The four exceptions are Alabama Power, Detroit Edison, Northeast Utilities, and Angra Brazil. At these four plants, if the installed speed switch should fail, the diesel would then fail to start, because of the failed speed switch, and not perform its intended design function. At this time, there is no substantive safety hazard because none of these plants have received any suspect speed switches."

"Therefore, this investigation and finding at Hope Creek is not considered a substantial safety hazard as defined by [10 CFR] Part 21. This is due to the redundancy in the starting circuitry. However, since there may be one remaining speed switch with an improper internal power supply, there may be a safety hazard depending on the configuration of the starting circuitry and the incorporation. of redundancy at that site."

(Call the NRC operations officer for a contact address and telephone number.)


BF5316
Coltec Industries
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