P2M Simulation Exercise on Past Fuel Melting Irradiation Experiments

This paper presents the results of Power To Melt and Maneuverability (P2M) Simulation Exercise on past fuel melting irradiation experiments, organized within Organisation for Economic Co-operation Development/Nuclear Energy Agency Framework IrraDiation ExperimentS (FIDES) framework by Core Group (CEA, EDF, SCK‧CEN) open to all FIDES members. The exercise consisted in simulating two power ramps where was detected: (1) xM3 staircase transient [ramp terminal level (RTL) 70 kW‧m−1, average burnup 27 GWd‧tU−1], carried out 2005 R2 reactor at Studsvik (Sweden), rodlet maintained its integrity, (2) HBC4 fast (RTL 66 48 GWd‧tU−1), 1987 BR2 SCK‧CEN (Belgium), cladding failed during experiment. joined 13 organizations from 9 countries using 11 different performance codes. In this paper, main are presented compared available postirradiation examinations (PIE) or on-line measurements (fuel clad diameters, rod elongation, pellet-clad gap, fission gas release). Since focus is assessment, determination boundary between melted/nonmelted consequent definition a radius PIE first discussed. During ramp, predicted most codes despite differences models. Higher discrepancies were observed that can be attributed partly uncertainty limited capability models describe partial ramp. Finally, possible code developments improve simulation presented.