MARS-LMR modeling for the post-test analysis of Phenix End-of-Life natural circulation

For a successful design and analysis of Sodium cooled Fast Reactor (SFR), it is required to have a reliable and well-proven system analysis code. To achieve this purpose, KAERI is enhancing the modeling capability of MARS code by adding the SFR-specific models such as pressure drop model, heat transfer model and reactivity feedback model. This version of MARS-LMR will be used as a basic tool in the design and analysis of future SFR systems in Korea. Before wide application of MARS-LMR code, it is required to verify and validate the code models through analyses for appropriate experimental data or analytical results. The end-of-life test of Phenix reactor performed by the CEA provided a unique opportunity to have reliable test data which is very valuable in the validation and verification of a SFR system analysis code. The KAERI joined this international program of the analysis of Phenix end-of-life natural circulation test coordinated by the IAEA from 2008. The main test of natural circulation was completed in 2009. Before the test the KAERI performed the pre-test analysis based on the design condition provided by the CEA. Then, the blind post-test analysis was also performed based on the test conditions measured during the test before the CEA provide the final test results. Finally, the final post-test analysis was performed recently to predict the test results as accurate as possible. This paper introduces the modeling approach of the MARS-LMR used in the final post-test analysis and summarizes the major results of the analysis