Design And Research On Segmented Monolithic Stud Tensioner Of Nuclear Reactor Pressure Vessel

At present,developing clean energy is one of the key measures to deal with climate and environmental challenges in the world.The clean energy development have been widely concerned.China clearly proposes to achieve the carbon peak in2030 and achieve the carbon neutralization in 2060,and nuclear power plays an increasingly important role in energy transformation.Most nuclear power plants use stud tensioner to dismantle reactor pressure vessels.Compared with single stud tensioner,monolithic stud tensioner have advantages such as uniform elongation,short time consuming and low radiation dose received.However,the AP1000 series,one of the three generation nuclear power plant,has structure that limits the use of traditional monolithic stud tensioner.The research and design of the monolithic stud tensioner for AP1000 reactor pressure vessel has great economic and social value.This paper analyzes the process of the stud tension of reactor pressure vessel,compares the technological differences between the single stud tensioner and the monolithic stud tensioner,then obtains the specific advantages of the monolithic stud tensioner.Based on the transportation path,crane lifting capacity,space dimension and tensile force parameters of AP1000 unit,the initial boundary conditions are determined.The single tensioning unit is designed,the key component material,structure size and stud holding mode are determined.The three-dimensional model of tensioning unit and stud is established.The mechanical properties of the tensioning unit are simulated and analyzed,and the rationality of structural is studied.Through the comparison of time,space and weight,the best segment strategy of the monolithic stud tensioner is determined.The design of the support cylinder,centering device and motor support of the tensioning unit in the section is completed,and the matching connection and matching mode between different segments are determined.The three-dimensional model of the monolithic stud tensioner is established and its spatial rationality is simulated..The hydraulic system and automatic control system of the monolithic stud tensioner are designed.The circuit diagram of the hydraulic system is drawn,the hydraulic system with high and low pressure pumps is determined,and the key technical parameters of the hydraulic pump,such as pressure,flow rate,pressure protection value and types of hydraulic components,are studied.Aiming at convenience and security,the architecture and software flow chart of control system are drawn.In conclusion,this paper presents a technical route of the segmented monolithic stud tensioner.The specific design of the segmented monolithic stud tensioner is completed.It provides a solution to the key problem that the monolithic stud tensioner cannot be used in the AP1000 series nuclear power plant.