Over the past year, the focus of RELAP5 use at the Savannah River Site has been on code applications to reactor accidents having a direct bearing on setting power limits, with a lesser emphasis on code development. In the applications task, RELAP5/MOD2.5 has been used to predict the thermal-hydraulic system response to large break loss of coolant accidents and to provide boundary conditions for a detailed fuel assembly code. This paper describes the significant phenomena affecting the ability of RELAP5 to perform the system calculations, the benchmarking work completed to validate the application of RELAP5 to Savannah River Site reactors, and the results of the system calculations. This paper will also describe the code and model development effort and will describe briefly certain significant gains
