SIMULATION OF FORMATION OF COLD DRAWN SQUARE PRESSURE TUBE OF ZIRCONIUM NIOBIUM ZR-NB ALLOY FOR BOILING WATER NUCLEAR REACTORS - A CASE STUDY

摘要

Boiling Water Reactors utilize Zirconium-Niobium (Zr-Nb) pressure tubes. These tubes serve the purpose of supporting rod bundles as well as providing passage for coolant. The thermal neutron absorption cross section of Zr-Nb is almost negligible compared to Uranium for thermal neutrons. Higher structural strength is the main advantages of square tube over circular tube; higher heat transfer area is an additional advantage. Ordinarily circular tubes and square tubes are formed by extrusion hot Zr-Nb alloy. Our aim was to find out an alternative manufacturing technique for mass production of Zr-Nb square tube. Recent advances in finite element method have led us to simulate and study cold drawing process. Here, study is carried out to simulate the process of formation of square tube from circular tube by cold drawing process, using finite element analysis.