Design of Gas Shield for Friction Stir Welding Machine

Sammanfattning: The research and development of the final disposal of the nuclear waste produced by the nuclear power plants is an important work done by The Swedish Nuclear Fuel & Waste Management Co. (SKB). As the demands on a final disposal increase the laboratory equipment has to be better in order to do valid experiments. Research on how the copper canister for the spent fuel will be manufactured and handled is done at the Canister laboratory in Oskarshamn, Sweden. The work presented in this report was to design a new gas shield for the friction stir welding machine at the laboratory. The welding machine seals the canisters containing the spent fuel which are then transported to the final disposal 500 meter down in basement rock. To minimize the amount of oxide particles in the weld zone SKB have to design a better gas shield that should deliver the required atmosphere around the welding area. The work contains a pre study phase where the important things to consider when designing are collected. Then ideas are generated and concepts created for a new gas shield. These concepts are evaluated by a pair wise comparison method in order to find the most promising concept. The concept chosen is then detail designed to come as close to a manufacturable design as possible.