Spectrum Indexes and Minor Actinide Fission Rate measurements in several fast lead critical cores in the Zero Power VENUS-F Reactor

Accelerator Driven Systems (ADS) along with traditional fast reactors are under study as a possible mean to transmute Minor Actinides (MA) and Long Lived Fission Products (LLFP). The Fast Reactor Experiments for hybrid Applications (FREYA) European FP7 project was launched in 2011 to support the designs of the ADS MYRRHA and Lead Fast Reactor (LFR) ALFRED. The main aim of the FREYA project is to validate reactivity monitoring methods in sub-critical cores, but essential efforts are also devoted to the validation of MA data in several VENUS-F zero power critical assemblies simulating LFR and MYRRHA critical cores. In these critical VENUS-F assemblies, fission rate ratios of MA such as Np-237, Am-241 as well as Pu-239, Pu-240, Pu-242 and U-238 to U-235 were measured using calibrated fission chambers. The measurements were analyzed using advanced computational tools including deterministic and stochastic codes and JEFF-3.1 nuclear data set. The C/E results of these fission rate ratios in several fast neutron lead based VENUS-F zero power assemblies are presented and discussed.