Fuel assembly for a nuclear reactor

A nuclear reactor fuel assembly in which the end fittings may be easily removed after the assembly has been irradiated so that defective fuel rods may be replaced or special fuel or burnable poison rods inserted therein. The fuel assembly is of the type wherein structural support is provided by several vertically extending hollow structural members attached at opposite ends to upper and lower end fittings. The upper and lower end fittings each comprise an end plate and means extending therefrom for alignment and support of the assembly within the reactor core. Threaded joints between the hollow structural members and the means for alignment form the connections between the hollow structural members and the upper and lower end fittings