Study on the Influence of Pressure Pipe Deformation on Life Extension of QINSHAN CANDU-6 HWR

In order to prove the feasibility of the second stage life extension of pressure pipe in Qinshan CANDU-6 heavy water reactor (HWR), the influence of the size change (axial extension, radial expansion and wall thickness thinning) in the second stage life extension of pressure pipe is analyzed comprehensively by means of Tang deformation equation calculation and data fitting, and the evaluation criteria and evaluation conclusions are given for the factors of the change of pressure pipe size. The results show that the radial expansion of the pressure pipe may be the restraining factor for the life extension of the pressure pipe. In view of this restraining factor, this paper gives the related influence analysis and countermeasures. This study lays the foundation for the second stage life extension of the pressure pipe of Qinshan No. 3 Nuclear Power Plant.