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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 56913 | 27 November 2023 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - EMD Cylinder Liner with Bore Deficiency | The following is a summary of the information provided by Engine Systems, Inc. (ESI) via fax: An edge or lip in the bore of an EMD (Brand name: Electro-Motive Diesel) cylinder liner prevented successful installation of the corresponding power assembly on an emergency diesel generator set. The lip is located axially at the bottom of the inlet ports and is present around the circumference of the bore. The EMD model 645E4 is a 2-stroke engine with air inlet ports in the wall of the cylinder liner. As the piston travels below the inlet ports, air box pressure scavenges and replenishes air to the power assembly. Installation of the power assembly requires lowering the piston through the liner in order to secure the connecting rod to the crankshaft. During this process the piston could not be lowered below the inlet ports due to the piston rings catching on the lip. The power assembly was not installed and therefore there was no safety hazard; however, if the defect had gone undetected there was the potential to damage engine components and possibly reduce load carrying capacity of the engine. The extent of the condition is this single cylinder liner, P/N 9318833, S/N 20M0938 used in the power assembly at Tennessee Valley Authority (TVA) - Sequoyah Nuclear Plant, Serial Number: 23H1306. Corrective Actions: For TVA-Sequoyah: No action required; the power assembly has been returned to ESI. For ESI: To prevent reoccurrence, ESI has revised the dedication package to include verification that bore machining is continuous along the entire length and no edges or lips are present. The revision was implemented on December 6, 2023.
Engine Systems, Inc. sent a revision to change the date of defect identification to November 27, 2023. Notified R2DO (Miller), Part 21 Group (email) | Emergency Diesel Generator | |
| ENS 56603 | 17 May 2023 04:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - Emergency Diesel Generator - Incorrect Bus BAR Installation | The following is a summary of the information provided by Engine Systems, Inc. (ESI) via fax: Copper bus bars are used at rectifier diode pigtail connections CR1, CR2, CR3, CR4, and CR7 to provide a common connection point for associated wiring to minimize the number of conductors on a single fastener. It is intended for the conductors to clamp directly to the bus bar, thereby maintaining a low resistance conduction path between components. ESI has determined the bus bars were installed incorrectly whereby the conductors are not clamped in direct contact, resulting in current now passing through the stainless steel fasteners. This configuration is undesired and will result in unnecessary heat generation which may lead to failure of the connection and therefore failure of the automatic voltage regulator (AVR) assembly. The AVR is relied upon to automatically regulate emergency diesel generator (EDG) terminal voltage. Failure of the AVR would impact the ability of the EDG to perform its safety-related function and therefore may impact the nuclear plant's ability to manage safety-related loads during an emergency event. This Part 21 applies to the bus bar installation for part numbers 72-12300-100-ESI, 72-14200-100-ESI, and 72-14000-100-6020. These part numbers impact Constellation Energy - Nine Mile Point, Avaltec/CFE - Laguna Verde (Div III), and Avaltec/CFE - Laguna Verde (Div II), respectively. Corrective Actions: Voltage regulator installed: Bus bar installation should be corrected immediately by restacking the components to ensure direct contact with all conductors. Voltage regulators in inventory (not installed): The bus bar installation should be corrected prior to installation. If desired, the customer may perform on site or the voltage regulator chassis may be returned to ESI for rework. | Emergency Diesel Generator | |
| ENS 55807 | 27 January 2022 04:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - ELECTRO-MOTIVE Diesel (EMD) Cylinder Head with Fireface Thickness Below Specification | The following is a summary of the information provided by Engine Systems, Inc. (ESI) via fax: ESI reported that a fatigue crack was discovered in the fireface of an EMD cylinder head, P/N 40121485, D/C 18K, installed on an emergency diesel generator set. The crack initiated on the coolant side and propagated through the fireface wall of the combustion side resulting in a water leak. Fatigue failure was likely caused by a reduced fireface thickness which reduced overall rigidity of the fireface, allowing increased deformation and ultimately failure due to high tensile stress at the blend between the fireface and valve seat. A reduced fireface thickness could result in a through wall crack that would introduce jacket water into the combustion chamber. Over time if the crack propagated or went undetected engine damage may occur. Ultimately, a crack in the fireface could lead to a failure of the diesel engine which would prevent the emergency diesel generator set from performing during a safety-event. This Part 21 applies to the Cylinder heads from D/C 18K, supplied within some power pack assemblies at Watts Bar Nuclear Power Plant. Corrective Actions: ESI recommends an ultrasonic thickness inspection on the fireface to confirm thickness is within specified range to plants with these power pack assemblies. ESI has also revised its dedication package to increase the number of ultrasonic thickness inspection points. An additional enhancement is the inclusion of an inspection map for guidance and clarity of the locations to be measured. The revision was implemented on March 15, 2022. Technical questions concerning this notification can be directed to Dan Roberts, Quality Manager and John Kriesel, Engineering Manager at (252) 977-2720. | Emergency Diesel Generator | |
| ENS 54588 | 19 March 2020 04:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Notification - Test Stand Deficiency | The following is a summary of information obtained from Engine Systems, INC. (ESI) via fax: On February 14, 2019, ESI determined that all new P/N H40084720 EMD fuel injectors they supplied are considered suspect. The endurance test stand utilized for new EMD fuel injectors was found to contain a deficiency that may damage injectors during the testing process. There is a potential for the actuating stem of the endurance test stand to strike the injector follower off center, creating side loading that results in inadvertent rubbing between the follower and body. The condition is exacerbated by a lack of continuous lubrication from the test stand. Over the 2-hour test duration, the running surface of the follower scores and metal particles are introduced into the top end of the injector. The migration of these particles through the injector could initiate a seizure. An improperly functioning fuel injector could affect the load carrying capability of the diesel engine and adversely affect the diesel's ability to perform its safety-related function. The licensees affected are Columbia, St. Lucie, Dresden, Fitzpatrick, Point Beach, Turkey Point, Quad Cities, and Grand Gulf. Points of Contact: John Kriesel, Engineering Manager and Dan Roberts, Quality Manager at Engine Systems Inc. 175 Freight Rd. Rocky Mount, NC 27804. Office number: 252-977-2720 | ||
| ENS 53084 | 20 November 2017 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part-21 - Auxiliary Feedwater Pump Power Supply Failure | The following report is an excerpt from a fax from Engine Systems, Inc.: Engine Systems Inc. (ESI) began a 10CFR21 evaluation on October 17, 2017 upon notification of a potential issue with power supply P/N 2938604 supplied to Vogtle Nuclear Plant. The power supply is installed in a safety-related control panel for the Terry Turbine driven auxiliary feedwater pump. Analysis determined the power supply failure was due to an internal rectifier diode failure which resulted in a short circuit on the power supply output. The evaluation was concluded on November 20, 2017 and it was determined that this issue is a reportable defect as defined by 10CFR Part 21. The power supply failure will adversely affect speed control of the turbine driven auxiliary feedwater pump and therefore may prevent safe shutdown of the nuclear reactor. This issue applies to all customers that have power supply P/N 2938604 within the date code range 0648 through 0723. ESI has supplied power supplies within the suspect date code range to (Vogtle and Farley). Point of Contact: Tom Horner, Quality Manager, 252-977-2720 | Auxiliary Feedwater | |
| ENS 53037 | 25 October 2017 04:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - Speed Switch Issue Results in Emergency Diesel Generator Failure to Start | The following information was received by facsimile from the vendor: Component: Speed switch P/Ns ESl50267C, ESl50267E, ESl50267H, and ESl50267K. Summary: Engine Systems Inc. (ESI) began a 10CFR21 evaluation on September 12, 2017 upon notification of a potential issue with speed switch P/N ESl50267K supplied to Hope Creek Nuclear Generating Station. The speed switch had reportedly failed in service which resulted in a failure to start of the emergency diesel generator (EDG). An analysis performed by Exelon Powerlabs determined the failure was due to a shorted capacitor that is installed on the speed switch's relay output contacts to ground. The evaluation was concluded on October 25, 2017 and it was determined that this issue is a reportable defect as defined by 10CFR Part 21. The speed switch output contacts are utilized in the engine's start circuitry and failure to function properly could adversely affect the safety-related operation of the emergency diesel generator set. Impact on Operability: If the resistance path to ground were sufficiently low, the ability of the relay output contacts to pick-up and/or drop-out associated components would be compromised. The speed switch relays are used in safety-related EDG start circuitry to control various electrical relays. Failure to properly control any of these components could adversely affect the safety-related operation of the emergency diesel generator. Root cause evaluation: The root cause of the failure is a deficiency in the design and selection of the EMC (Electromagnetic compatibility) mitigating components. Consideration was not given for the impact of voltage transients imparted on the capacitors during coil de-energization. For customers without suppression from the inductive kick, the magnitude of voltage transients may be sufficient to damage and ultimately degrade the capacitors to the point of failure. Affected nuclear plants include Nine Mile Point, Quad Cities, Dresden, Davis Besse and Hope Creek. | Emergency Diesel Generator | |
| ENS 52642 | 27 March 2017 04:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - Identification of Failed Diode Surge Suppressor with Internal Manufacturing Defect | The following information is excerpted from an Engine Systems, Inc. (ESI) report received via fax: COMPONENT: Diode Surge Suppressor Allen-Bradley P/N: 199-FSMZ-1 SUMMARY: Engine Systems Inc. (ESI) began a 10CFR21 evaluation on February 10, 2017 after receiving notification from FirstEnergy Corp - Perry Nuclear Power Plant (PNPP) of a manufacturing defect in a diode supplied by ESI. The evaluation was concluded on March 27, 2017 and it was determined that this issue is a reportable defect as defined by 10CFR21. The manufacturing defect identified was in a diode of the same date code as two diodes that failed while installed at PNPP. The failed diodes resulted In loss of class 1E control power which could have prevented the emergency diesel generator set from performing its safety related function. Discussion: In January 2007, ESI supplied a governor system upgrade to PNPP. The upgrade replaced the existing Woodward EGB-35C governor/actuator, EGA control (w/ resistor box), and MOP with an EGB-35P governor/actuator, 2301A control, and DRU. The electrical components were housed in a control panel assembly. To support the slow start feature of the new system, 4 relays were used, each of which used a surge suppressor (flyback) diode. PNPP experienced two failures in 2016 of the aforementioned diodes supplied by ESI. The diodes are Allen Bradley part number 199-FSMZ-1 and they were installed across the coils of Allen-Bradley 700DC series relays. The Allen-Bradley date code stamped on the side of the diodes is BX9. The failure in both cases resulted in a short circuit condition that resulted in a loss of class 1E control power to the EDG. Root cause evaluation: The root cause of the failure is determined to be a manufacturing defect internal to the diode. Though an analysis of the diodes that failed at PNPP was unable to be performed due to their condition, the analysis performed on a degraded diode of the same date code, BX9, detected an internal manufacturing defect. Affected Users: A listing of users with suspect diodes includes FirstEnergy - Perry, Entergy - Grand Gulf, Progress - Shearon Harris, and Duke - Shearon Harris. A total quantity of 34 diodes are suspect. Corrective Action: All affected users . . . (identified above) . . . should perform the following: 1. Review their inventory for suspect diodes listed in Table 1. Any suspect diodes should be removed from inventory and discarded. 2. Determine if suspect diodes listed in Table 1 have been installed. Thus far, ESI has identified degraded diodes from date codes BX9 and ZX9 and it is possible that diodes from the other date codes are degraded as well. ESI has been unable to determine an expected service life. Therefore, the recommendation is to remove or replace any installed suspect diodes as soon as possible. Note that the applications for which this diode has been supplied (Enterprise engine control panels) used the same style Allen-Bradley relays as original equipment but without diode surge suppressors. It is therefore acceptable to remove the diodes and expect no change or impact to the existing equipment. To prevent recurrence of this issue, the following has been Implemented by ESI: 1. The test procedure for the diode has been enhanced to increase the test voltage and decrease the allowable leakage current. Although this was not the cause of the failure, it may have prevented identification of a degraded condition. This corrective action has already been implemented. 2. A review has been performed of other diodes supplied by ESI and at this time only this one part number is affected. A typical diode would be procured and/or sold under the diode manufacturer part number; whereas in this case it was procured from the relay manufacturer. Testing was performed using typical relay values in lieu of the diode manufacturer's acceptance criteria. If you have any questions, you may call: Tom Horner Quality Assurance Manager Tel: (252) 977-2720 ESI Report ID: 10CFR21-0116, dated 03/27/17 | Emergency Diesel Generator | |
| ENS 51495 | 26 August 2015 04:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Report - Speed Switch Capacitor Failure | The following is a summary of a submitted facsimile: Engine Systems Inc. (ESI) began a 10 CFR 21 evaluation on August 26, 2015 upon notification by Harris Nuclear Plant of a ground fault condition after installing two speed switches, P/N ESI50267B, supplied by ESI. Subsequent investigation revealed the condition was due to a failed capacitor installed across the relay output to ground within each speed switch. The evaluation was concluded on October 22, 2015 and it was determined that this issue is a reportable defect as defined by 10 CFR Part 21 . The speed switch output contacts are utilized in the engine's start circuitry and failure of the contacts to function properly could adversely affect the safety-related operation of the emergency diesel generator set. This issue only affects one part number (qty 6) supplied on one customer purchase order: ESI Sales Order: 3013958 Part Number: ESI50267B Customer: Duke Energy Progress - Harris Nuclear Plant Customer P.O.: 00763117 ESI Serial Numbers: 3013598-1.1-1, 3013598-1.1-2, 3013598-1.1-3, 3013598-1.1-4, 3013598-1.1-5, 3013598-1.1-6 C of C Date: April 10, 2015 Point of Contact: Tom Horner, Quality Assurance Manager, Engine Systems, Inc., phone (252) 977-2720 | Emergency Diesel Generator | |
| ENS 49830 | 10 February 2014 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Report - Failed Pressure Regulator During Post-Installation Edg Pressure Testing | Component: Starting air pressure regulator (Nordberg P/N 1776 506). Summary: Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 12/13/13 upon completion of a failure analysis performed on a pressure regulator part number 1776 506 (S/N 20776487) that was returned by Brunswick Nuclear Plant (BNP) following a failure that occurred during post-installation pressure testing on their emergency diesel generator (EDG) set. The downstream pressure would not maintain its set point and began to equalize to the inlet pressure. This evaluation was concluded on 02/10/14 and it was determined that this issue is a reportable defect as defined by 10CFR Part 21. The failure to regulate downstream pressure is attributed to an o-ring within the piston guide assembly of the pressure regulating valve that was improperly installed at the factory. Failure of the o-ring's pressure boundary allows inlet pressure to leak to the outlet pressure side eventually causing equalization to occur. This equalization is undesirable since it could lead to pressures that exceed the capabilities of the engine's downstream air start solenoid valve; thereby potentially preventing the diesel engine from starting during an emergency event and performing its safety related function. | Emergency Diesel Generator | |
| ENS 49534 | 25 October 2013 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part21 - Diode Cr7 Wiring Reversed on Automatic Voltage Regulator Panels | The following is a summary of information received via facsimile: Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 10/25/2013 after receiving notification from APS-Palo Verde Nuclear Generating Station that diode CR7 on their automatic voltage regulator (AVR) panels had the wiring connections reversed. During installation of the AVR panels, generator output voltage buildup was observed to be longer than expected during fast start testing. The slow voltage buildup was determined to be caused by a lack of generator field flashing. Troubleshooting revealed that the field flash diode CR7 wiring was reversed. The evaluation was concluded on 11/11/2013, and it was determined that this issue is a reportable defect as defined by 10CFR21. The incorrect wiring of diode CR7 prevents field flashing of the generator. Lack of generator field flashing can result in failure of generator voltage buildup, or excessive voltage buildup time, during starting of the emergency diesel generator (EDG). This condition could therefore have impacted operability of the EDG and prevented it from performing its safety related function. APS-Palo Verde is the only affected customer. This reversed CR7 wiring condition only applies to the five (5) AVR panels (P/N 072-12200-100-PVNGS) shipped to Palo Verde on ESI sales order 8001720 (4 panels shipped in May 2013 and 1 panel shipped in June 2013). | Emergency Diesel Generator | |
| ENS 48844 | 22 March 2013 05:00:00 | 10 CFR 21.21(a)(2), Interim Report for Comply or Defect in Component | Diesel Fuel Injectors Failed a Pressure Test | The Tennessee Valley Authority (TVA) recently identified that three (3) fuel injectors that were to be used on the 3A Emergency Diesel Generator failed a pressure test. Corrective Action Program documents were written to document the failure of the fuel injectors to pass a pressure test and to require performance of an engineering evaluation of the condition. It was concluded that this condition has the potential to constitute a reportable condition pursuant to Title 10 of the Code of Federal Regulations (CFR), 10 CFR 21, 'Reporting of Defects and Noncompliance,' and, as such, requires additional evaluation. The TVA is working with Engine Systems, Inc., to determine the cause of failure of the fuel injectors. At this time, the evaluation is not expected to be complete until May 31, 2013. Pursuant to the reporting requirements of 10 CFR 21.21(a)(2), if the evaluation of the deviation or failure to comply potentially associated with a substantial safety hazard cannot be completed within 60 days (i.e. by March 23, 2013), an interim report must be submitted to the NRC. Name and Address of the Individual Making the Interim Report: Mr. K. J. Polson Vice President Browns Ferry Nuclear Plant Tennessee Valley Authority Post Office Box 2000 Decatur, Alabama 35609-2000. Identification of the firm supplying the basic component which fails to comply or contains a defect (under evaluation): Engine Systems, Inc (ESI) 175 Freight Road Rocky Mount, North Carolina 27804. | Emergency Diesel Generator | |
| ENS 45875 | 23 March 2010 04:00:00 | 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Emd Jacket Water Pump with Incorrect Impeller Orientation | The following is a summary of a report received from Engine Systems, Inc. via facsimile: Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 03/23/10 following a corrective action request from Entergy - Grand Gulf. The request was written as the result of Grand Gulf having an EMD jacket water pump with an incorrect impeller. Specifically, the impeller installed in the pump was for rotation opposite of the pump housing. The evaluation was concluded on 04/26/10 and was determined to be a reportable defect as defined by 10CFR21. EMD diesel engines utilized for emergency diesel generator sets use two engine jacket water centrifugal pumps (one for each bank) to circulate fluid throughout the engine for cooling. Each pump is mounted on the front of the engine and rotates in the opposite direction of the engine crankshaft. For single engine generator set applications (i.e. left hand rotation engine, viewed from the rear of the engine), the pumps used on each bank contain identical components; the only difference is the position of the impeller housing in relation to the pump shaft housing. When viewed from the front of the engine, these water pumps rotate counterclockwise (see Figure 1 below). For tandem generator set applications, one engine is left hand rotation and the other is right hand rotation. For each engine, the pumps used on each bank contain identical components and the only difference is the position of the impeller housing in relation to the pump shaft housing. However, for a right hand rotation engine the water pumps rotate clockwise when viewed from the front of the engine In summary, because these pumps use impellers that rotate in both clockwise and counter-clockwise directions, it is possible that an impeller could be installed with a design rotation opposite that required for the associated pump housing. A review has been performed to evaluate the impact on past supply of EMD water pumps. Historically, ESI has supplied a quantity of over 280 water pumps under 17 different EMD part numbers dating back to 1988. The pump returned by the customer (Grand Gulf) was supplied in January 1997. After reviewing the history of dedication activities performed on the water pumps it was found that dedication reports for EMD water pumps have always contained an inspection requirement to verify the correct operational rotation; however reports written prior to 2000 did not include a clear visual depiction of what the correct operational rotation is. It appears that this was an isolated incident where the inspector made an error when performing the inspection. Since April 2000, all EMD water pumps shipped were inspected to a dedication report that included a clear visual depiction of proper impeller geometry. This one incident is the only known instance of an EMD water pump with the incorrect impeller. ESI recommends that as a precaution, all customers with an EMD water pump in stock which was supplied by ESI prior to April 2000 should perform a visual inspection to ensure the correct impeller is installed. A pump which has been installed on the diesel engine is considered acceptable based on successful operation of the diesel engine. The impeller inspection is easily performed, without disassembly, by looking into the inlet port of the pump to confirm the orientation of the impeller matches the pump housing. A listing of the various part numbers supplied prior to April 2000 is included in Table (below). Listing of Water Pump P/Ns Supplied Prior to April 2000 Part Number Rotation Bank Type of Engine 40004235 LH RIGHT 16 & 20-645E4 & E4B 40004234 LH LEFT 16 & 20-645E4 & E4B 8347607 LH LEFT 16 & 20-645E4 & E4B 8364236 RH RIGHT 16 & 20-645E4 & E4B 8364237 RH LEFT 16 & 20-645E4 & E4B 8269664 LH RIGHT 12-645E4 & E4B 9336390 LH LEFT 12-645E4 & E4B 8269638 LH LEFT 12-645E4 & E4B 8324588 RH RIGHT 12-645E4 & E4B 8324589 RH LEFT 12-645E4 & E4B NOTE: The ESI report did not provide an information on specific nuclear power plant licensees that may possess these components.
Two sentences were added to address the safety hazard which is created or could be created by this defect. Installation of the incorrect impeller would result in considerable loss of engine cooling water flow. This would cause elevated engine cooling water temperature that could impact engine performance and/or load carrying capability with the possibility of eventual engine failure, thereby preventing the emergency diesel generator from performing its safety related function. Notified R1DO (Powell), R2DO (Sykes), R3DO (Peterson), R4DO (Lantz), PART 21 GROUP via e-mail. | Emergency Diesel Generator | |
| ENS 45548 | 8 December 2009 05:00:00 | 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Woodward Governor Servo Failure Due to Silver Sulfide Corrosion of Surface Mount Resistors | Woodward failure analysis report #85572-R001, dated 10/9/09, addressed two separate (model) PGPL remote servo failures. The failure analysis report discusses a silver sulfide corrosion issue with surface mount resistors used in the PGPL remote servo feedback transmitter circuitry. Woodward part number 9903-539 consists of a PGPL actuator and a remote servo. The PGPL actuator is mounted on the turbine's governor drive and the remote servo (Woodward part number 5296-044) is mounted at the steam valve. Hydraulic lines interconnect the PGPL to the remote servo. The PGPL actuator and remote servo was supplied by Engine Systems, Inc. (ESI) to the Callaway and Vogtle nuclear plants as part of a digital governor upgrade (Woodward 505 control) on their steam turbine generators. These are the only nuclear plants that use the P/N 9903-539 actuator remote servo assembly. LISTING OF WOODWARD PIN 9903-539 PGPL ACTUATORS WITH SUSPECT RESISTORS Serial Number Born Date Shipped to 12369963 Nov 2000 Callaway 13305595 July 2002 Callaway 13798414 May 2004 Vogtle 13798415 May 2004 Callaway 14141720 Feb 2005 Vogtle 14409400 Sep 2005 Vogtle Note: Serial numbers 12369963 and 13798414 recently had the feedback board replaced during the failure analysis; these require no further corrective action. |