Research On Key Technology About Underwater Restoration Of Head Delivery System (HDS) In Nuclear Power Plant

For under the environment of high radiation, pressure, vibration, friction and hydrogen adsorption, some parts of the nuclear power plant will become worn, aged and even disabled, and this phenomenon or hidden trouble of this will become more and more following the increase of the nuclear power plants. So the most important safeguard of the plant operation is the regular overhauling of the underwater high radiation in-service equipment of nuclear power plant, and the trouble of high radiation dose and feasibility of underwater operation shall be settled first.In this paper, for the goal of restoration of Pakistan Cashima Nuclear Power Plant (CNPP) irradiation surveillance capsule, we'll research and develop the craft, technology and the special equipment and tools for the irradiation surveillance capsule restoration with independent intellectual property rights, according to the overhaul decision making of Qinshan Nuclear Power Company (QNPC), and basing on the main body machine structure of Head Delivery System (HDS) which is available in 2002.Based on this, this paper focus on the research of the irradiation surveillance capsule restoration craft ---- basing on the original Westinghouse HDS basic structure, redesign and develop a new control system by adopting the reliable method of PLC technology and servo-motion control technology, and realize the independent intellectual property rights of the design and development of the new control system. Against the three typical tasks condition of HDS mechanical structure during the process of the work, we take the means of Solid works COSMOS finite element analysis software, analyze the structure deformation prediction and reach the following achievements: the rule of main structure deformation, microscopic deformation motion of the key catch point and the accuracy impaction to the irradiation surveillance capsule installation which guarantee the installation accuracy of the irradiation surveillance capsule support. Finally, we carry out the analysis of the hot workshop lifting process associating with the practical situation at QNPC site and lay the foundation of the commissioning.This topic lays a solid foundation for the completion of the actural maintenance task in CNPP C-1.