Pressurized water reactors (PWRs) are the predominant type of nuclear power plant globally, with their reactor pressure vessels (RPVs) subject to stringent in-service inspection (ISI) requirements as mandated by regulatory standards. However, the complex curved surface of the reinforcement part presents challenges for ultrasonic testing in the outlet nozzle-to-shell weld areas, resulting in inaccessible zones that lack practical quantitative analysis methods for volume coverage. This study systematically parameterized the geometric features of the outlet nozzle reinforcement part, including the cone, fillet, and ellipse. It introduced seven categories of ultrasonic beam tangent segmentation algorithms based on spatial curves. Using Pro/E software, we developed a 3D ultrasonic beamline model of inaccessible zones and validated its accuracy against two-dimensional data obtained from AutoCAD. Building on this foundation, a fully parametric simulation model and discrete volume data were employed to plot the continuous curves of inaccessible zones' volume on the side of the typical outlet nozzle reinforcement part as a function of ultrasonic incidence angles, elucidating the nonlinear, multi-stage superimposed impact of complex surface characteristics on the volume of inaccessible zones. This research provides vital theoretical support and a methodological basis for optimizing ultrasonic testing processes and quantitative evaluation of volume coverage in nozzle areas with complex surfaces, particularly saddle-like profiles.

This paper introduces the current situation, advantages and disadvantages of the design of large-diameter pipeline inspection mechanism at home and abroad. Based on the typical characteristics of the main coolant line of nuclear power plant and the requirement of minimizing the personnel residence time, a new type of pipe inspection mechanism with high load, lightweight and multi-function is developed. The stress model of the lightweight gear ring in various statuses is established with detailed stress conditions of the gear ring are calculated, and then the maximum deformation and stress are simulated. By comparing the vertical deviation principle of prototype and new rigid structures, the coupling optimization method of probe is explained. Through the practical application in the nuclear power plant, the overall performance and lightweight effect of the system are verified.

The inlet nozzle to shell weld of PWR RPV has the characteristics of complicated geometry,while the definition of ultrasonic inspection area is different among several in-service inspection codes,and these above factors cause the inaccessible zones to show non-linearity change.In order to find the special changing rules,the parametric model of the nozzle weld was established,meanwhile the simulation method which caused by the slope feature was deeply analyzed,which help to deduce the discriminant criteria for the right-side inaccessible zones simulation.Based on the criteria,with typical parameters of the PWR RPV and ASME code,it is easier to acquire the mathematics diagram of the volume for both left-side and right-side inaccessible zones to refraction angle,with the help of lots of scattered data set by 3D simulation software.The diagram can interpret an optimization method for getting minimum inaccessible zone volume for phase array or conventional method.The research takes the advantage of increasing the chance of finding the ultrasonic defects,especially for the mathematic laws of accessibly and distribution of the phase array or conventional ultrasonic technics in same type of welds.

Canopy welds (Ω)in CRDM housing are welded seals j oining stainless material and playing an important role in leak-proof for CRDM housing.The paper firstly summarizes and outlines the development of the immersion ultrasonic inspection techniques for canopy welds,and then determines the test parameters such as wave type,probe frequency,wafer dimension and layer thickness ,and finally carries out the verification test.And through the test it proves that the technique could meet the test requirements of canopy welds (Ω)in CRDM housing.

基于反应堆压力容器出口接管焊缝的马鞍形特征,依据ASME和RSE-M规范的超声检查需求,建立出口接管马鞍形通用空间曲线方程组,推导主声束在接管左、右侧不可达区域的边界计算方程.采用Pro/E软件对不可达区域建模仿真,计算随机入射角的不可达体积占比值,其结果可对典型几何特征导致的接管超声不可达区域进行定量研究.

The invention relates to an ultrasonic automatic scanning device for a large-aperture pipeline in a nuclear power plant. The ultrasonic automatic scanning device comprises a mechanical scanning part, an electric control part and a pipeline part, wherein the mechanical scanning part comprises a circumferential guide rail part, a circumferential moving module and an axial moving module; the circumferential guide rail part comprises an annular body and a plurality of supporting legs which are mounted on the inner side of the annular body and are capable of moving along the radial direction of the annular body; the circumferential moving module comprises a circumferential guide rail fixed on the annular body, an arc-shaped fixed plate which is detachably mounted on the circumferential guide rail and is capable of moving along the circumferential guide rail, and a circumferential driving motor which is fixed at one end of the arc-shaped fixed plate and is meshed with the circumferential guide rail; the axial moving module comprises an arc-shaped frame detachably mounted on the arc-shaped fixed plate, a probe disk which is parallel to the arc-shaped fixed plate, can slide in the arc-shaped frame and is used for fixing ultrasonic probes, an axial driving motor fixed on the arc-shaped frame, and a transmission mechanism which is connected with the axial driving motor and is used for driving the probe disk. On one hand, the mechanical scanning part is modularized, so that the occupation space can be effectively reduced, and the mechanical scanning part can conveniently move and be mounted in the narrow space of the nuclear power plant; on the other hand, the mechanical scanning part is in a detachable quick connection locking mode, so that the mounting time is shortened.

The first Chinese Evolutionary Pressurized Reactor (CEPR) nuclear power plant is being built on the Taishan site, Guangdong Province. The regulation of application imposes a rule to perform the Pre-Service Inspections on the components of the main primary system with qualified Non-Destructive systems.

The present invention discloses a non-destructive testing method of detecting robot and its nuclear reactor pressure vessel. Comprising: a column assembly; a plurality of support legs, each support leg one end fixedly connected to said upright assembly, and the other end detachably connected to the column assembly and pressure vessel axis and the axis line coincides with the pressure vessel ; a first robot arm provided with a first scanning probe assembly for the pressure vessel cylinder; the second arm, which is provided with a second probe assembly for scanning the lower head of the pressure vessel; a third arm , which is provided with a third scanning probe assembly for the pressure vessel portion of the nozzle; and a fourth robotic arm, which is provided with a threaded bolt hole fourth probe assembly for scanning and pressure vessel flange for scanning the pressure vessel the fifth probe assembly ligament area of ​​the bolt hole of the flange; main rotary joint, which is rotatable about the axial direction of the post assembly pivotally connected to the lower portion of the upright assembly, said second arm by a pivot joint about a perpendicular an axial direction of the upright assembly rotatably connected to the main rotating joint, the other robot arm is detachably connected to the main pivot joint.

反应堆压力容器检查机的支撑腿结构起定位和支撑作用,其结构的合理性对反应堆压力容器检查机的定位精度和可靠性具有重要影响.针对第三代核电站EPR堆型核反应堆压力容器结构,设计了具有自动定心功能的支撑腿结构.采用有限元方法分析了支撑腿结构的可靠性,并进行了验证力学试验.试验结果印证了相关理论分析结果,证明该支撑腿结构的设计是合理可行的.

Based on the forming and loading principles of multi-stranded wire helical spring,the article firstly pays more attention to the state distributing of the contact facet. With the help of predecessors' work, the novel model then divides the facet into three zones, which including spacing zone, spring zone and friction zone. On further more research, it analyses the boundary and contact judgment quantitative conditions under the coordination of the Normal-P_tangent-Tangent , respectively.

The invention relates to a reed numerically-controlled machine tool steel wire tensity examination and the revolving twist. Rope installment, which belongs to the area of many reed numerically-controlled machine tool process technology. This invention installment mainly includes the reducing decelerate the electrical machinery, the transmission gear gudgeon, the steel wire tensity sensor system, the steel wire guide mechanism and so on. Its characteristic is as follows: the servo decelerates electrical machinery is one or two, the transmission gear including the drive gear and the driven gear is one pair or two pairs, and the gudgeon is one decked or double-decked. Because this invention installment s simply to be controlled, it raises the steel wire introduction's efficiency and many reed production's efficiency, reduces the labor intensity, and avoids the steel wire having the plastic deformation. Besides it raises many reed product manufacture qualified rate and the service life, and can survey the steel wire's actual tensity, thus it guaranteed each steel wire's tensity uniformly and so on. Therefore this invention may widely used in many reed processing profession, many reed which is produced by this invention can be widely applied in the frequency reciprocating motion equipment of the high sky in the automobile, aviation, machinery department and so on.