Benchmarking results of the COMETHE code

The validation of a code for fuel rod behaviour prediction requires a comparison of its results with corresponding experimental data. Benchmarking of the COMETHE code has been done in parallel with its development, but more tine has been spent on that work than in the development of the models themselves. Three experiments are presented; they have been selected from amongst those used by BN for the calibration as being good examples of various features: (1) The ELP2 experiment, performed in the EL3 reactor by CEA-Saclay and related to fuel restructuring. Results show that behaviour is very well modelled in COMETHE. (2) The BR3/VN post-irradiation data, which show a large sensitivity of the fission gas release to the power level and reveal that coupling between the fission gas release model and the gaseous swelling model is beneficial. (3) The BM01 low density fuel BN pin, irradiated in the FBR RAPSODIE: close agreement is found between the cracking pattern computed by the 'pivot model' and the experimental cold state results. A lot of the benchmarking results arise from the EPRI RP 397 Fuel Rod Modeling Code Evaluation Project. (orig.)