论文部分内容阅读
大亚湾核电站现有安注系统浓硼水箱硼浓度为21 000 μg/g。由于浓硼水箱在高温下运行(否则会结晶)，蒸发量大，补水频繁，系统杂质增多，相关设备及管道结晶堵塞，使安注系统可用性下降，Io(设备不可用率)消耗多，这给正常运行与维修带来很大的困难。根据有关国际经验，提出将浓硼水箱的硼浓度从21 000 μg/g降至7 000 μg/g(常温下不结晶)以便从根本上解决这一问题。分析了浓硼水箱改造对安全分析的影响(主要是堆芯DNBR计算和安全壳内压力响应计算)以及对电厂的其它影响。所用的分析程序和方法是大亚湾核电站引进的经过NRC认可的西屋公司的程序和方法，这些程序也得到了NNSA的认可。分析结果表明，将浓硼水箱硼浓度从21 000 μg/g降至7 000 μg/g，当发生主蒸汽管在安全壳内断裂时，堆芯DNBR满足安全准则，安全壳最高压力在设计压力限制值之内。浓硼水箱硼浓度降低对大亚湾最终安全分析报告其它事故分析和电厂运行没有不良影响。大亚湾核电站浓硼水箱改造的安全分析已经得到NNSA的批准并已实施。
Daya Bay Nuclear Power Station existing security system boron concentration of concentrated boron water tank 21 000 μg / g. As the concentrated boron water tank runs at high temperature (otherwise it will crystallize), the evaporation is large, the water is replenished frequently, the system impurities increase, the related equipment and pipeline crystallization block, so that the safety of the injection system reduces the availability, Io (equipment unavailability) To the normal operation and maintenance brought great difficulties. According to relevant international experience, it is proposed to reduce the boron concentration of concentrated boron water tank from 21 000 μg / g to 7 000 μg / g (not to crystallize at normal temperature) in order to fundamentally solve this problem. The impact of the heavy boron water tank retrofit on safety analysis (mainly core DNBR calculations and calculation of pressure response in containment) was analyzed and other effects on the plant were analyzed. The analytical procedures and methods used are the procedures and methods introduced by the NAC Accredited Westinghouse at the Daya Bay Nuclear Power Station and these procedures are also endorsed by the NNSA. The analysis results show that when the concentration of boron in concentrated boron water tank is reduced from 21 000 μg / g to 7 000 μg / g, the core DNBR meets the safety criteria when the main steam pipe breaks in the containment. The maximum containment pressure at design pressure Within limits. The boron concentration in the concentrated boron water tank has no adverse effect on other accident analysis and plant operation in the Daya Bay Final Safety Analysis Report. The safety analysis of the Daya Bay Nuclear Power Station Borate conversion has been approved by the NNSA and implemented.