DC ARC-PLASMA FABRICATION OF TUNGSTEN PIPING AND TUBING FOR IMPROVED NUCLEAR FUEL CYCLE PROCESSES

THIS PROJECT IS DIRECTED TOWARD THE NEAR-NET SHAPE FABRICATION OF TUNGSTEN TUBING AND PIPING AS OPPOSED TO THE CURRENT MANUFACTURING METHOD OF GUN DRILLING. THE PROCESS IS LOW PRESSURE PLASMA SPRAYING (LPPS), A SPRAY-CAST PROCESSTHAT OFFERS ADVANTAGES TO THIS APPLICATION. NOT ONLY CAN PROCESS PIPING, TUBES, AND TRANSFER LINES BE FABRICATED, BUTPAST EXPERIENCE INDICATE THAT ELBOWS AND FITTINGS MAY ALSO BE SO CONSTRUCTED. IN PHASE I, THE USE OF LPPS FOR FABRICATING AND JOINING LENGTHS OF TUNGSTEN TUBING IS BEING EXPLORED, FOLLOWED BY STUDIES OF THE USE OF LPPS FOR FABRICATING LONGER LENGTHS OF TUBING, USING REUSABLE OR RENEWABLE MANDRELS. FINAL CHARACTERIZATIONS OF THE TUNGSTENDEPOSITS WILL BE DONE AT BOTH ROOM TEMPERATURE AND HIGH TEMPERATURE. BECAUSE THE LPPS PROCESS PERMITS THE FABRICATION OF LAYERED STRUCTURES AND TUNGSTEN IS A RATHER EXPENSIVE MATERIAL, FURTHER ECONOMIC ADVANTAGES MAY EVENTUALLY BE GAINED BY USING PURE TUNGSTEN LININGS WITH LESS EXPENSIVE ALLOY OVERLAYS TO PROVIDE STRUCTURAL STRENGTHAS PART OF A PHASE II STUDY.