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NUREG Investigation Report No. NUREG-LER-2012-001 2012 Operational Operational
Shearon Harris 1 号机 主蒸汽隔离阀活塞环腐蚀致关闭延迟
Shearon Harris Nuclear Power Plant, Unit 1 (NRC LER 50-400/2012-001-00)
Related equipment → Control valve (control_valve)
0Fatalities
0Injuries
CorrosionMechanism code COR
⌗Failure Mode · ISO 14224 Mapping
Damage mechanism (recorded in KB)
CorrosionCOR
Internal damage-mechanism code (not ISO 14224)
ISO 14224:2016 functional failure code
OTH · Other
Mapped to ISO OTH — Other.
1What Happened

主蒸汽隔离阀(MSIV)活塞环长期腐蚀→关闭行程超时被判不可运行（违反技术规格书）

2Root Cause

阀门活塞环意外长期腐蚀；MSIV 未正确纳入气动阀计划；未识别阀门劣化机会

3Reliability Lessons (from investigation root cause)
  • The 'Root Cause' above is the core lesson of this accident; not split further.
4Associated Failure Mechanisms (Keywords)
主蒸汽隔离阀 隔离阀 活塞环 腐蚀 关闭延迟 阀门 气动阀
About the Failure-Mode Code (click to expand)

The mechanism code COR 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) — Licensee Event Report (LER)
Official Report：www.nrc.gov ↗
Data Verification：verified_url_nrc_pdf_2026-07-24
↗Related Failure Modes · Traceability
Valve Body Corrosion / Erosion fmValve-seat Surface Damage -> Internal Leak fm_2Valve-plug Erosion fm_3Valve Stem Sticking / Bending fm_4Packing Wear -> External Leak fm_5Diaphragm Rupture fm_6Spring Fatigue / Fracture fm_7I/P Converter Failure i_pFeedback Link Loosening fm_8Coil Burnout fm_9Valve Plug Sticking -> Failure to Actuate fm_10Contact Corrosion / Poor Contact fm_11Filter-element Blockage -> Insufficient Supply fm_12Pressure-Relief Valve Set-point Drift fm_13波纹管失效 bellows_failure阀体腐蚀 corrosion_body冲蚀/冲刷腐蚀 MECH-EROSION大气腐蚀 MECH-ATMOS锅炉水/凝结水腐蚀 MECH-BWC电偶腐蚀 MECH-GALVANIC
Report No. NUREG-LER-2012-001 · 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.