Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 56993 | 23 December 2023 06:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - MINI-GEN Signal Generator Defect | The following is a summary of the information provided by Fairbanks Morse Engine via email: Arkansas Nuclear One (ANO) Unit 2 had a failure of a mini-gen signal generator on the opposed piston emergency diesel generator. Bench testing after removal from the engine showed an erratic signal, and this was confirmed by Fairbanks Morse. Fairbanks Morse destructive analysis revealed wear of the dynamic surface on the stator bushing inside diameter. The cause of the worn stator bushing is most likely due to inadequate lubrication on the dynamic surfaces, outside diameter of the shaft and inside diameter of the stator bushing. Possible causes of inadequate lubrication could be failure to apply enough lubrication to the dynamic surfaces during the manufacturing process or deterioration/evaporation over time. Fairbanks Morse has implemented corrective actions to address this issue, and they are estimated to be completed by May 23, 2024. Affected plants with potentially defected parts: Arkansas Nuclear One, Edwin I. Hatch Nuclear Plant, Joseph M. Farley Nuclear Generating Station, Limerick Generating Station, and Prairie Island Nuclear Generating Plant. Point of Contact: Martin Kurr Quality Assurance Manager Fairbanks Morse 608-364-8247 Martin.Kurr@fmdefense.com Fairbanks Morse Notification Report Number: 23-02 | Emergency Diesel Generator | |
| ENS 56992 | 22 December 2023 06:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - Air Start Valve (Bent Bottom Stem) | The following is a summary of the information provided by Fairbanks Morse Engine via email: Prairie Island Nuclear Generating Plant (PINGP) was conducting a planned replacement of emergency diesel generator air start solenoid valves when it discovered that the bottom stem appeared to be bent and observed air leakage. PINGP returned five valves to Fairbanks Morse, and they returned them to the manufacturer, ASCO. ASCO reassembled one valve and confirmed there was air leakage through the valve. The leakage path was from the air supply port to the exhaust port when the valve was in the de-energized normally open state. ASCO functionally tested the remaining four valves and found a second valve that also leaked. ASCO and Fairbanks Morse have implemented corrective actions to address this issue. Fairbanks Morse will notify PINGP and Limerick Generating Station. Affected plants with potentially defected parts: Prairie Island Nuclear Generating Plant and Limerick Generating Station. Point of Contact: Martin Kurr Quality Assurance Manager Fairbanks Morse 608-364-8247 Martin.Kurr@fmdefense.com Fairbanks Morse Notification Report Number: 23-01 | Emergency Diesel Generator | |
| ENS 56200 | 27 October 2022 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Report - Fairbanks Morse Engine Emerency Diesel Generator Electronic Speed Control Module | The following information was provided by Fairbanks Morse (FM) via email: Facilities affected: FM Sales Order Item Affected Facility Serial Number 40135890 12996949 Farley 22436624 40132483 12996949 Limerick 22444358 40130845 12996949 Limerick 22444359 40130158 12996949 Hope Creek 22277182 Basic component which fails to comply or contains a defect: Emergency Diesel Generator Electronic Speed Control Module, Woodward 2301A Nature of defect: In some 2301A controls, 1 nF capacitors may have been loaded in place of 150 pF capacitors. This could affect circuitry controlling the units' crystal, speed signal and reset dynamics, and power supply operation. Safety hazard which could be created by such defect: This issue can prevent affected 2301A controls from starting up or may lead to unscheduled shutdown of affected controls. It can also prevent the prime mover from obtaining a stable speed response, causing it to hunt or overspeed. In some cases, the RESET potentiometer may run out of range to adjust the unit for stable operation or desired prime mover speed response, resulting in prime mover performance outside of specification limits. Fairbanks Morse Engine will notify affected licensees no later than 3 Nov 2022, and repair returned affected units. Additional corrective actions will be documented in the Fairbanks Morse corrective system under PD-1102. Any installed affected Speed Control should be removed from service as soon as practical and returned to Fairbanks Morse for repair. If affected controller is installed and licensee experiences unstable speed response, the electronic speed control should be turned off and the emergency diesel generator should be allowed to operate using the mechanical governor system. POC: Martin Kurr, Quality Assurance Manager (608) 364-8247 | Emergency Diesel Generator | |
| ENS 46523 | 16 November 2010 06:00:00 | 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Part 21 Report for Potential Safety Hazard on Speed Switch Installed on Emergency Diesel Generator (Edg) | The following was received via fax: (Fairbanks Morse (FM) determined) that when the speed switch assembly was mounted on a conductive surface, the voltage regulator grounded out the 24 volt direct current power through the heat sink preventing the speed switch from operating. This condition was not detected prior to the first speed switch being shipped to Hope Creek in September, 2010. It was never installed on the EDG prior to being recalled. The unit was returned to FM and has since been reworked and verified to be in compliance with the latest design to eliminate the deficiency. | Emergency Diesel Generator | |
| ENS 43294 | 9 April 2007 05:00:00 | 10 CFR 21.21 | Part 21 Notification - Diesel Cam Roller Bushing Failures | The (fuel pump) cam roller bushing part number 16100527 (and part number 16600336 for the kit containing cam roller bushings) for the Fairbanks Morse Engine Opposed Piston engine Emergency Diesel Generator shipped prior to August 2001 may be made from an incorrect material that is too soft for the application. The subject emergency diesel generator would not have been able to achieve its maximum load rating and therefore not have been able to perform its intended function. The potentially affected plants are: Alabama Power/Farley Arkansas Power Amergen /GPU/TMI Constellation/BG&E Detroit Edison/Fermi Dominion/Millstone Vepco Georgia Power/Hatch Vermont Yankee Exelon/PECO - Limerick/Peach Bottom FPL/NMC/IES/Duane Arnold NMC Prairie Island/Northern States Progress Energy (CP&L) SCANA/South Carolina Electric and Gas Electronuclear (Electrobras) | Emergency Diesel Generator | |
| ENS 40699 | 21 April 2004 05:00:00 | 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Fairbanks Morse Engine Has Determined a Potential Safety Hazard with the Woodward Digital Reference Unit (Dru) | On April 21, 2004, Fairbanks Morse Engine evaluation determined a potential safety hazard exists for Woodward DRU's. The FM P/N is 12998236 and the Woodward P/N is 9903-439. The defect exhibits erratic ramp up of speed and hence the inability to reach rated RPM and inability to apply load to the engine. The cause has been traced to a random contamination problem of an integrated circuit (IC) in DRU's manufactured by Woodward between November 2000, and January 2002. The rate of occurrence is less than 10 in the US and approx 20 worldwide. There are approx 38,000 Woodward units worldwide that use this IC. Only one US nuclear utility has experienced this failure and the failure occurred during testing prior to declaration of operability. In all cases, the failure occurs within a very few hours of operation. Therefore, if a DRU has been installed and has been operating for many hours/years, it is not at risk for this failure. The utilities that FM has supplied DRU's to in the timeframe identified that may be affected include the following: Utility Site Year Shipped
FP&L Seabrook 2001
WCNOC Wolf Creek 2001
The above utilities are also being notified and affected DRU's will have IC's replaced as necessary.
Fairbanks Morse Engine evaluation has determined a potential safety hazard exists for Woodward Digital Reference Units (DRUs). The FM P/N is 12998236, and the Woodward P/N is 9903-439. A list of specific affected S/N's is identified in the letter dated 01/12/06. The defect exhibits erratic ramp up of speed and hence the inability to reach rated RPM and inability to apply load to the engine. The cause has been traced to a random interaction between solder flux and integrated circuit (IC) material causing chip delamination. This condition is further described in Woodward Service Bulletin 01363, dated December 2005. This same problem had been previously reported on 4/23/04, and at that time was thought to only affect DRU's manufactured between November 2000 thru January 2002. The manufacturer thought they had purged their stock of the specific IC chips that manifested the problem, but additional chips have been found in their system that now extends the affected time period to December 2005. DRU's that have had IC chips replaced per the earlier 10 CFR 21 notification are not affected due to the use of a different solder flux that does not introduce the problem. The utility that FM has supplied DRU's to in the timeframe identified that are affected Include the following: Utility Site Detroit Edison Fermi First Energy BV-2 SCE&G VC Summer The above utilities are also being notified and affected DRU's will have IC's replaced as necessary. Notified R1DO (Conte), R2DO (Munday), R3DO (O'Brien), NRR EO (Mayfield), and emailed and faxed to Part 21 Coordinator (Tabatabai) | ||
| ENS 40610 | 25 March 2004 06:00:00 | 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Part 21 Notification Involving Potential Safety Hazard for Blowers on Op Engines | Subject:Roots Blower on OP Engines On March 23, 2004, Fairbanks Morse Engine evaluation determined a potential safety hazard exists for blowers (P/N 16609294) on OP engines. It is possible that the aluminum rotors can slip on the steel shaft and cause rotor-to-rotor or rotor-to-housing contact which could cause blower failure and inability of engine to perform its safety function. The defect was caused by improper cleaning of the shaft prior to casting the rotor onto the shaft. This causes an inadequate bond and allows the aluminum rotor to move axially on the steel shaft. Sample testing of rotors has found this condition to exist to varying degrees on approximately 75% of rotors produced between 1998 and 2003. (4) blowers were shipped to nuclear utilities that may be affected: Utility Site Blower S/N Exelon Limerick (RB813A, RB3871, RB816) Entergy ANO-2 (RB814) To date, no engine failures have been experienced as a result of this problem. However, the potential exists. All slipped rotors have been found during routine maintenance inspections. This condition has been found to manifest itself within a low number of hours of operation. Therefore, the longer the rotors run and maintain proper clearance, the less likely they are to be affected by this condition. The affected utilities will be notified to evaluate inspection results and replace as necessary. | ||
| ENS 40524 | 16 February 2004 06:00:00 | 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Part 21.21 Notification of Potential Safety Hazard Associated with Use of Turbocharger | On February 12, 2004, Fairbanks Morse Engine evaluation determined a potential safety hazard associated with the use of ABB turbocharger model VTC-304 on OP engines only. Torsional resonance has been found in the rotating assembly which is excited by exhaust pulses. The resonance manifests itself as either a bent or broken shaft, slipped compressor wheel, cracked compressor wheel or complete rupture of the compressor set. Once failure occurs, engine power cannot be sustained. This condition is corrected by machining the rotating assembly to tune the natural frequency away from operating conditions. The only affected site is Crystal River 3. (6) turbos have been shipped to this site. None of the turbos have been installed and all are in storage. The FM parts department will arrange to have the turbos returned to the factory to have the necessary machining performed. |