Irradiation experiment analysis for cross section validation.

An analysis of the irradiation experiment TRAPU performed at the French fast reactor PHENIX is presented. The observed C/E’s on the final densities of the measured isotopes for the different basic data files (JEF2.2, ENDF/B-V, and ENDF/B-VI) indicate some large discrepancies that a subsequent sensitivity analysis attributes to specific cross sections of actinides. Among them: 238 U σ(n,2n), and capture cross sections of higher plutonium isotopes, 241 Am, 243 Am, and 242 Cm. capture cross sections. Very useful information is gained by performing a simulated adjustment that uses the observed C/E’s and the calculated sensitivity coefficients. In particular this adjustment shows that a good consistency can be reached on final adjusted cross sections, and associated new C/E’s, starting from different data files. The same adjustment shows that we cannot reach definite conclusions on many fission cross sections ( 238 Pu, 241 Pu, 242 Am, and 243 Cm), because the experiments were not sensitive enough to these parameters.