某核电厂主蒸汽管道振动原因分析及解决方案探讨

某核电厂在升功率试验及满功率运行时，发现主控室的噪声超过了设计目标值。经过测量，认为主蒸汽管道振动并通过支撑和贯穿件传播到主控室是造成主控室噪声超标的主要原因之一。本文应用流体力学软件和声学分析软件，采用流声耦合分析的方法，对主蒸汽管道的流场和声场进行了分析。在主蒸汽安全阀支管处和主蒸汽隔离阀空腔中存在着声共振现象，是导致主蒸汽管道振动的主要原因。根据主蒸汽管道振动的原因，可以通过振动源头治理、传播路径治理等方法降低主控室噪声。 

Research on Lower C Seal Cutting Technology for AP1000 Large Canned Pumps

The canned motor reactor coolant pumps are used in the Unit 1and Unit 2 in Sanmen Nuclear Power Plant. The lower C seal has to be cut apart by the special way and tool during the pump disassembly. According to the structure of the pump, the functional requirements of the cutting scheme are defined and a cutting toole is designed and developed. The method of finite element analysis (FEA) is used to verify and optimize the structure strength and cooling effect of the tool, to ensure the cutting accuracy and service life. This cutting scheme and the tool are applicable in the narrow and deep space, and the fixed distance cutting can be conducted with high efficiency, high reliability, and without foreign material and air radiation pollution. The scheme and the tool can be used in the nuclear main pumps maintenance in other nuclear power plants, and has certain industrial value.