A method to fabricate nuclear fuel plate assembly in annular Al pipes using Friction stir welding is described. Tool design and welding parameters resulting in defect-free solid-state bonding of Al tube to Al fuel plate having a pull strength higher than 100 Lbf is claimed. Due to reduced heat input, the thermal distortion of the Al tube is significantly lower than what can be obtained using fusion welding methods. Welds can be performed in circular and/or spiral weld paths around the tube. The combination of tool geometry, and welding parameters results in high-quality joints with minimal pipe distortion. This approach can be applied to the assembly of many research reactors.