反应堆冷却剂系统环路热管段破口事故分析

摘要

对核电站安全进行研究,了解其薄弱环节，并采取有效措施保证核安全，这具有非常重要的意义。而安全分析在核电站中更起着尤为重要的作用。

对主回路冷却剂系统热管段大小破口失水事故现象的描述，研究了事故发生后对安全功能的需求及其实现方式，采用小事件树的方法进行事件序列的模型化。其次，采用故障树方法对安全功能的失效进行模型化，并在建树的过程中对系统做了一些相关的假设。最后，通过模型的定量化找出安全壳喷淋系统的功能失效是对堆芯损毁贡献最大的事件，降低此系统功能失效的发生概率是降低此初因事件导致堆芯损毁概率的有效方法和途径。

关键词概率论分析，确定论分析，冷却剂系统热管段，大小破口失水事故

Abstract

All experts of related fields conduct a study on the plants understand their weak links and take effective measures to ensure nuclear safety, which is important practical significance. Further, safety analysis is playing a more important role for nuclear power plants．Combination with the phenomenon description of accident of big and small LOCA on primary coolant piping，requirements on safety functions and their realization ways had been studied after the accident occurred，the event sequences were modeled by adopting small event tree method．Secondly, the failures of the security functions were modeled by adopting the fault tree method，and some assumptions of the systems have been done in the process of the establishment of FTA．Finally, the functional failure of the containment spray system has been found that it Was the biggest contribution to the core damaged by identifying the models and reducing the probability of failure of this system was the effeaive ways and means to minimize the probability of damage to the core of this initial event．

Key Words probabilistie analysis, deterministic analysis, coolant system heat pipe, coolant pipeline big and small LOCA

目录

中文摘要.......................................................................................................................................... I Abstract......................................................................................................................................... II 1 引言 (1)

1.1 概述 (1)

1.2 核电厂安全分析法 (2)

1.3 小结 (3)

2 核反应堆冷却系统描述 (4)

2.1 压水堆冷却剂系统的功能 (4)

2.1.1 主要功能 (4)

2.1.2 辅助功能 (4)

2.2 压水堆冷却剂系统的系统说明 (4)

2.3 压水堆核电厂一回路主要辅助系统 (5)

2.3.1 化学和容积控制系统 (6)

2.3.2 余热排出系统 (6)

2.3.3 安全注射系统 (7)

2.3.4 安全壳喷淋系统 (7)

2.3.5 管道与设备布置 (8)

2.4 小结 (9)

3 确定论分析冷却系统环路热管段破口事故 (10)

3.1冷却系统环路热管段大破口失水事故过程分析 (10)

3.1.1 喷放阶段 (10)

3.1.2 再灌水阶段 (12)

3.1.3 再淹没阶段 (12)

3.1.4 长期冷却阶段 (13)

3.2冷却剂系统环路热管段小破口失水事故过程分析 (13)

3.3小结 (14)

4 概率论分析冷却系统环路热管段破口事故 (16)

4.1 冷却剂系统的运行 (16)

4.2 冷却剂系统失水事故的原因 (16)

4.3 事故分类 (16)

4.3.1 冷却剂系统环路热管段大破口失水事故 (16)

4.3.2 冷却剂系统环路热管段小破口失水事故 (19)

4.4 小结 (25)

结论 (27)