[en] Fuel rod wear, due to vibration, is a continuing concern in the design of liquid cooled reactors. In this report, the methodology and models that are used to predict fuel rod vibrational response and vibratory wear, in a light water reactor environment, are discussed. This methodology, is being followed at present in the design of Westinghouse Nuclear Fuel. It is difficult to develop reliable design methods for predicting fuel rod wear because: 1. The dynamic characteristics of the fuel rod assembly are complex. 2. The basic excitation mechanisms causing fuel rod vibration require complete characterization. 3. The parameters that determine the wear between materials must be established. Fuel rod vibrations are expressed as the normal bending modes, and sources of rod vibration are examined with special emphasis on flow-induced mechanisms in the stable flow region. (Auth.)