Analysis of the PROFIL and PROFIL-2 Sample Irradiation Experiments in Phénix for JEFF-3.1 Nuclear Data Validation

The PROFIL and PROFIL-2 experiments, performed in the Phénix demonstration fast reactor, irradiated 130 small separate samples containing almost pure isotopes. These highly accurate experiments are a very specific and powerful source of information on the nuclear data of major and minor actinides and several fission products. Their analysis is carried out using the ERANOS-2.1 code system associated to JEFF-3.1 cross-section, fission yield, and decay data. The consistency of the results demonstrates the overall good quality of the actinide nuclear data and experimental techniques used and points out where specific improvement is necessary: fission yields of ²³⁵U on neodymium isotopes (5% bias) and integral capture cross sections of the actinides ²³²Th, ²³⁴U, ²⁴²Pu, ²⁴⁴Cm, ²⁴⁶Cm (more than 10% bias), ²³³U, ²³⁷Np, ²⁴¹Pu, and ²⁴³Am (bias between 5 and 10%). The optimal values of the branching ratios for ²⁴¹Am capture (0.85 on ^242gAm and 0.15 on ^242mAm) are consistent with the latest evaluation data in the fast neutron range. A similar analysis characterized the degree of accuracy of the integral capture cross sections of 19 fission products. Two new experiments of the same kind have been irradiated in Phénix and will undergo dissolutions and isotopic analyses. When they are completed, the analysis of the results will provide additional useful data in both a standard and a slightly moderated neutron spectrum.