On the Vibrational Behavior of Pressurized Water Reactor Fuel Rods

Received July 30, 1980 Accepted for Publication March 10, 1982 The results of a study on the vibrational behavior of pressurized water reactor (PWR) fuel rods are presented. It is shown that a linear finite element model is representative for the low amplitude vibrations. A parametric study on the pellet diameter and the plenum spring force suggests that the vibrational behavior should be expected to change with irradiation. The amount of this change, however, can hardly be estimated from the very limited available experimental data. A typical PWR clad-to-grid connection is analyzed in detail from the point of view of vibratory wear. A procedure is presented to compute a minimum grid spring force consistent with the maximum allowed vibration amplitude.