The inspection of materials used in nuclear industry is a critical issue for the safety of components exposed to stress or/and corrosion, and the utilities claim for faster, more sensitive, and more flexible techniques. Technologies based on Eddy Current (EC) flexible array probe and magnetic sensors with high sensitivity such as giant magneto-resistance (GMR) are a good solution to improve the detection performances. This paper presents recent developments done in the framework of a joined R&D program between CEA and the French Institute for Radiological Protection and Nuclear Safety (IRSN). The first development addresses the inspection of nuclear components with complex shapes. A flexible array probe based on micro-coils etched on Kapton has been developed, and its performances have been assessed for the inspection of nuclear components such as reactor residual heat removal (RHR) pipes. The flexibility of the sensor reduces greatly the lift-off noise, optimizes the coupling and thus enhances the detection of flaws. The second development deals with the detection of deeply embedded flaws. An EC probe based on GMR sensor has been developed and evaluated for the inspection of the outer face of the RHR mock-up. Cracks induced by thermal fatigue have been successfully detected under a ligament of 7mm.