Study of Hydrogen Evolution for the Outlet Rolled Joint of Candu Reactor Pressure Tube Under Operation Thermal Cycle

Abstract Hydrogen is presented in CANDU reactor pressure tubes component as initial protium from manufacturing as well as deuterium ingress from heavy coolant occurring during operation. Ingress is more prominent at the rolled joint connection at each end of the pressure tube such that concentration gradients cause inboard diffusion of the hydrogen. High hydrogen concentration could reduce ductility and toughness of material via delayed hydride …