Accident Lesson Card · Brunswick 控制楼仪表空气干燥器故障结冰导致控制室空调/应急通风丧失（2011）

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NUREG Investigation Report No. NUREG-LER-2011-003-BRUNSWICK 2011 Operational Operational

Brunswick 控制楼仪表空气干燥器故障结冰导致控制室空调/应急通风丧失（2011）

Brunswick Steam Electric Plant, Units 1&2, North Carolina, USA (Progress Energy)

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

控制楼仪表空气干燥器因制冷剂压力低导致仪用空气管路结冰堵塞，丧失控制空气，连带控制室空调(3 系统)与应急通风(2 系统)不可用，被迫旁路干燥器恢复

2Root Cause

对制冷剂低压缺乏监测，未能及时发现导致仪用空气管路结冰；纠正措施含更换干燥器并修订程序在低压时旁路

3Reliability Lessons (from investigation root cause)

The 'Root Cause' above is the core lesson of this accident; not split further.

4Associated Failure Mechanisms (Keywords)

干燥器仪表空气结冰堵塞控制空气旁路 air dryer instrument air freeze ice blockage bypass

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_ML12046A835_2026-08-08 (Brunswick LER 11-003-00 原文)

↗Related Failure Modes · Traceability

吸附剂失效/粉化 adr_desiccant_degrade出口露点升高/带水 adr_dewpoint_rise再生切换阀失效 adr_regen_valve_fail再生加热器失效 adr_heater_fail再生吹扫气异常 adr_purge_loss控制器/露点仪失效 adr_control_fail干燥塔腐蚀/内衬失效 adr_vessel_corrosion液态水夹带（分离器/疏水阀失效） adr_moisture_carryover吸附床沟流/偏流 adr_bed_channeling系统压降升高 adr_pressure_drop双塔切换时序紊乱 adr_dual_tower_sync_fail

Report No. NUREG-LER-2011-003-BRUNSWICK · 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.