Validation of important fission product evaluations through CERES integral benchmarks

Optimization of energy resources suggests increased fuel residence in reactor cores and hence improved
fission product evaluations are required. For thermal reactors the fission product cross sections in the JEF2.2 and
JEFF3.1 libraries plus new evaluations from WPEC23 are assessed through modelling the CERES experiment in
the DIMPLE reactor. The analysis uses the lattice code WIMS10. Cross sections for 12 nuclides are assessed. The
thermal cross section and low energy resonance data for 147,152Sm and 155Gd are accurate to within 4%. Similar data
for 109Ag, 143Nd and 149Sm are within 8% while 95Mo, 99Tc, 103Rh, 133Cs and 145Nd are within three benchmark
standard deviations at ∼12%. The use of the 172 XMAS group scheme is adequate for all nuclides considered except
153Eu.