Radiant Deformation Of PWR AFA17×17 Fuel Assembly And Core Loading Of Deformed Fuel Assembly

The fuel assembly deformation such as bend and torsion due to radiant deformation. Remarkable fuel assembly deformation may result in significant trouble that the fuel assembly is not loaded properly, fuel assembly is damaged due to attrition during fuel loading process, control rod is not inserted successfully into fuel assembly, and the quadrantal power of reactor core is deviated. Nowadays the events that control rod unsuccessful inserted caused by fuel assembly bend were discovered on kinds of reactors. It happened in domestic and foreign nuclear power plants that fuel assembly was damaged by attrition during deformed fuel assembly loading in reactor core. So it is important signality to enhance PWR nuclear power units safety and stable operation that we study fuel assembly deformation and loading in reactor core, solve the difficult problem during core loading caused by fuel assembly deformation, and reduce the risk of reactor operation caused by fuel assembly deformation.This paper focuses on the radiant fuel assembly deformation of AFA 17×17 fuel assemblies ( including AFA-2G and AFA-3G fuel assembly ) in Qinshan II reactor core. First part of the paper defines the AFA-2G and AFA-3G fuel assembly and their radiant deformation principle and characteristic. Then the paper explores some exterior rules of fuel assembly deformation after investigating the data of deformed fuel assemblies measured in Qinshan II unit outages. It aims at the radiant deformation and puts forward six methods which applied in deformed fuel assembly loading in the reactor core. It emphasizes on demonstrating that the"short shoehorn"loading method is a safety, high efficiency and convenient handling method to solve the deformed fuel assembly loading. By this method, Qinshan II have successfully solved the difficult problem that how to load safely and high efficiently the radiant deformed fuel assemblies in reactor core. The paper detailed checks the safety and application analysis of the"short shoehorn"tool. On the other side, PMC system (fuel assembly transfer handling and storage system) is necessary to be improved on relevant performance in order to fit into the loading operation of radiant deformed fuel assembly. The paper also discusses the performance upgrading on main facilities of PMC system in Qinshan II nuclear power plant, then based on this, studies the technical development of intending advanced PWR fuel assembly, describes the prospect of future trend and technical performance of the new age of PMC system in PWR nuclear power units.