WP3: Joining of ATF clads & testing of joints/welds

Participants: SCK•CEN, TUD, POLITO

WP3 Leader:  POLITO

Introduction

WP3 – Joining of ATF clads & testing of joints/welds: WP3 targets the development of reliable joining approaches for the different ATF cladding material concepts and the validation of the joint reliability by dedicated testing activities comparing the joint properties with the cladding material property requirements defined at the project outset (WP10). Developing a reliable joining approach is mainly a challenge for the SiC/SiC composite clads; hence, the selection of appropriate joining materials and methods for the SiC/SiC clads are two important objectives of WP3. Another goal is the establishment of a reliable testing approach to determine the shear strength of SiC/SiC joints. The reliable joining of coated and surface-alloyed commercial clads is less challenging, since coating and surface modification of clads will follow the welding of the substrate clads according to clad-specific welding technologies. Conventional welding technologies ensure hermetic sealing of the fuel-loaded cladding tubes by welding end caps on both ends of the tubes. Even though welding technologies are established for commercial clads, the performance of the produced welds must still be assessed. WP3 will assess the performance of as-produced joints/welds, joints/welds exposed to water/steam (WP5) and ion/proton irradiation (WP6), so as to understand the in-service degradation mechanisms of ATF joints/welds. The optimised joints/welds must pass the set of critical screening tests prior to neutron irradiation in BR2.

Deliverables

D3.1: Application-driven optimisation of SiC/SiC joints

D3.2: Proof-of-concept SiC/ SiC joints