Qualification of gadolinium burnable poison: Interpretation of MELUSINE/GEDEON-II spent fuel analysis

The analysis of GEDEON-II experiment confirmed the good prediction of actinide build-up in PWR fuel pins using JEFF-3.1.1 library, as well as the trend to underestimate 238U(n, 2n). This work has demonstrated the satisfactory accuracy of the APOLLO2.8 calculation for the depletion of 155Gd and 157Gd poisoning isotopes: averaged C-E biases on their consumption throughout irradiation are −0.5 ± 1.0% and −0.7 ± 1.6% (RMS), respectively.