Incorporating sensitivity and uncertainty analysis to a lattice physics code with application to CASMO-4

This paper describes the implementation of classical perturbation theory based sensitivity and uncertainty analysis to the reactor physics code CASMO-4 in the context of the UAM (Uncertainty Analysis in Best-Estimate Modelling for Design, Operation and Safety Analysis of LWRS) benchmark. The theoretical background as well as practical guidelines for similar work are reviewed and the developed methodology is described in detail. A technique is proposed for handling a discrepancy between the code and covariance libraries regarding the amount of reactions present in the cross-section model. Numerical results for PWR and GEN-III MOX pin-cell test problems are presented and compared to TSUNAMI-1D. The results are in accordance with theoretical considerations and reflect the characteristics of the developed methodology.

► Classical perturbation theory (cpt) based sensitivity and uncertainty analysis has been implemented to casmo-4. ► Theoretical background and practical considerations for similar work are reviewed. ► A technique for unifying covariance matrices with total capture and scattering cross-sections is presented and analyzed. ► Numerical results are presented for pwr and gen-iii mox pin-cells and compared to tsunami-1d.