Accident Lesson Card · Real investigation (tap external link for official report)
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NUREG Investigation Report No. NUREG-LER-1998-002-BROWNSFERRY 1998 Operational Operational
Browns Ferry 3 号机 480V 停役盘备用馈线断路器拒合导致母线瞬时失电(1998)
Browns Ferry Nuclear Plant, Unit 3, Alabama, USA (TVA)
Related equipment type → switchgear (switchgear)Related equipment type → circuit breaker (circuit breaker)
0Fatalities
0Injuries
FailureMechanism code FAI
Failure Mode · ISO 14224 Mapping
Damage mechanism (recorded in KB)
FailureFAI
Internal damage-mechanism code (not ISO 14224)
ISO 14224:2016 functional failure code
OTH · Other
Mapped to ISO OTH — Other.
1What Happened

480V 停役盘 3B 备用馈线断路器在倒闸时未能如期合闸,导致该盘及所属负荷(含 RPS 母线、应急通风)瞬时失电,触发专设安全设施动作

2Root Cause

断路器位置开关联动触点被一根错位导线干扰无法正常闭合;根本因为导线布线不当及开关盖板拆装错误

3Reliability Lessons (from investigation root cause)
  • The 'Root Cause' above is the core lesson of this accident; not split further.
4Associated Failure Mechanisms (Keywords)
开关柜 断路器 配电盘 拒合 失电 倒闸 switchgear circuit breaker bus fail to close de-energize
About the Failure-Mode Code (click to expand)

The mechanism code FAI shown on this card is the KB's internal damage-mechanism abbreviation (not an ISO 14224 code); it describes how the equipment failed. The 'ISO 14224 Mapping' block above maps it to the correct ISO functional failure code (which describes what the equipment failed to do) — these are two distinct dimensions in ISO 14224. The mechanism follows the narrative in the card body.

5Evidence Source (transparent)
Authority:U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Reactor Regulation
Official Report:www.nrc.gov ↗
Data Verification:verified_url_nrc_adams_ML18039A314_2026-08-08 (Browns Ferry LER 98-002 原文)
Related Failure Modes · Traceability
绕组绝缘热老化 winding_insulation_thermal_aging内部故障产气(匝间/饼间短路,DGA 异常) dissolved_gas_fault套管闪络/渗漏 bushing_flashover有载分接开关触头磨损/卡涩 oltc_contact_wear_sticking冷却器/油泵/风扇失效 cooling_system_failure铁芯多点接地/过热 core_ground_fault_hotspot绝缘油劣化/受潮 oil_degradation_moisture分接开关切换油室燃弧/爆裂 tap_diverter_arc绕组机械位移/变形(短路电动力) winding_mechanical_displacement储油柜/呼吸器堵塞 conservator_breather_blockage温度指示/保护误动拒动(WTI/OTI) temperature_indicator_failure瓦斯继电器误动/渗漏 buchholz_relay_nuisance突发短路耐受失败 short_circuit_withstand_failure异常噪声/振动(铁芯松动) noise_vibration_abnormal套管接线端/引线连接过热 terminal_connection_overheat断路器拒动 breaker_fail_to_trip断路器误动跳 breaker_spurious_trip母排连接点过热 busbar_overheating局部放电 partial_discharge操动机构卡涩 breaker_mechanism_jam电流互感器/电压互感器故障 ct_pt_failure保护装置失效 protection_relay_failure内部电弧故障 arc_flash_event绝缘老化 insulation_degradation控制电源丧失 control_power_loss接地/二次回路接地不良 grounding_fault在线测温装置失效 thermal_monitoring_failure柜体腐蚀(危险区域) enclosure_corrosion通信中断 communication_loss蓄电池单体容量衰减 battery_cell_degradation蓄电池热失控 battery_thermal_runaway逆变器故障 inverter_fault整流器故障 rectifier_fault静态开关失效 static_switch_fail控制板/固件故障 control_board_fault冷却风扇失效 cooling_fan_failure输入浪涌/电压骤降 input_surge输出过载跳闸 output_overload蓄电池后备时间不足 battery_capacity_loss手动/自动旁路故障 bypass_path_failure通信中断 ups_communication_loss
Report No. NUREG-LER-1998-002-BROWNSFERRY · Data from NUREG (US NRC) public investigation conclusions, compiled by Reliability AI, for reliability demonstration purposes only. This case is derived from public incident investigation reports for learning purposes only. AIM does not endorse or guarantee its accuracy.