Impact of a new ²³⁵U(n_th, f) fission yields evaluation on the decay heat uncertainty calculated for a PWR cell UOX at 45 GWd/t. The library of evaluated data used for the calculation is JEFF-3.3 (full bold black line labeled “JEFF-3.3”). The dashed lines correspond to the uncertainty propagation of nuclear data covariances but where the independent fission yields of ²³⁵U(n_th, f) have been replaced by one of the new evaluations (thin dashed line: only the variances of independent ²³⁵U fission yields are propagated in the Decay heat calculation; bold dashed line: the full variance-covariance matrix of the new ²³⁵U fission yields evaluation are propagated).