姜武

摘 要：重水堆停堆大修期间燃料仍留在堆芯并需要连续冷却，给大修期间的核安全提出了非常高的要求，而低水位检修是大修期间核安全风险的最高阶段，低水位检修处于关键路径或次关键路径，工期的长短直接影响大修的总工期。以核安全至上和质量第一为前提，合理安排好每项检修任务，优化低水位检修计划，采取核安全风险控制措施，将核安全风险降至最低。文章介绍了低水位期间的核安全风险，分析了低水位检修窗口安排策略，并阐述了在历次大修中结合重水堆机组特点所采取的一系列核安全风险管控措施，以确保低水位检修的核安全。

关键词：重水堆 低水位 核安全 风险管理

中图分类号：TM62 文献标识码：A 文章编号：1674-098X（2017）01（a）-0134-03

Nuclear Safety Risk Control in the Low Level Drained Maintenance of CANDU Unit

Jiang Wu

（CNNP Nuclear Power Operations Management Co. Ltd.， Haiyan Zhejiang， 314300， China）

Abstract：Nuclear fuel remains in the core during the outage of CANDU unit and needs continuous cooling， which brings very high requirements nuclear safety during the outage. And the low level drained maintenance is the highest stage of nuclear safety risk during outage. Low water level maintenance is in key path or second key path， and the length of a project directly affects the total duration of the outage. On the premise of nuclear safety first and quality first， optimize the low level drained maintenance plan， take nuclear safety risk control measures， and minimize the risk of nuclear security. This article introduces nuclear safety risks during the low water drained maintenance and elaborates a series of CANDU-specific risk control measures taken during the past plant outages to ensure nuclear safety during the low level drained maintenance.

Key Words：CANDU unit；Low level drained；Nuclear safety；Risk management

重水堆機组大修期间核燃料仍保持在堆芯，存在着与功率运行期间同样的核安全风险，即面临反应堆意外临界、堆芯余热不能及时导出引起堆芯燃料元件损坏，放射性物质外泄等风险。停堆大修期间存在工期紧任务重、状态转换频繁、交叉检修作业多、接口协调复杂等特点，是各类事件的高发期。核安全是贯穿大修全过程的头等大事，秦山三厂自商运以来一直非常重视机组大修期间的核安全风险管理。低水位检修是大修期间核安全风险最高阶段，管理层到基层员工始终坚持核安全至上理念，借鉴国内外同行经验，在实践中逐渐摸索出一套行之有效的重水堆机组大修期间的核安全风险管理办法，以确保低水位检修的核安全。……