The aim of this work was to simulate the experimental irradiations of PWR-type fuel rods in experimental reactors using the ALCYONE fuel performance code developed by CEA. It took place within the framework of the P2M project, which is an international irradiation program, led by the core group CEA, EDF and SCK-CEN (Belgium). This irradiation program consists in studying the behaviour of an instrumented fuel rod submitted to a power ramp, until reaching a molten volume fraction in the fuel centreline. The final objective was to calculate the fission gas kinetics and more precisely the fission gases detected inside the plenum for the dimensioning of the P2M fuel rod, with particular focus on the evaluation of the pressure inside its plenum due to burst releases of fission gases.