Patent Number: 050698648
Section: abstract

A spring-and-spacer assembly for maintaining fuel rods in a upright preferred position in a fuel assembly of a nuclear reactor core is provided. The spring has a leg portion and two loop portions, one at each end of the leg. Each loop engages an ear formed in a ferrule of the spacer. Each loop contains a dimple which contacts an ear of the ferrule. The central leg portion has a dimple, or a projection, which contacts a fuel rod and biases the fuel rod against stops. The spring load is transmitted to the ferrule ears by the dimples in the spring loops. Preferably, the spring rotates about the dimple when flexed, contributing to spring flexibility. The high spring flexibility permits use of the spring in connection with small rod-to-rod spacing fuel assemblies. This construction permits providing a low-mass, low-surface area spring, in turn providing for low neutron absorption and low flow obstruction.