Feasibility of experiments in the TAPIRO reactor to improve minor actinides nuclear data

The main challenge associated with the R&D on nuclear waste management is the radiotoxicity reduction of the nuclear spent fuel, which is mainly due to some elements, i.e. plutonium and other minor actinides (MAs) such as neptunium, americium and curium. By fissioning these elements in appropriate nuclear reactors, they can be eliminated. A deeper knowledge in the nuclear data of these MAs is of primary importance in order to deal with their transmutation. Focusing on this goal, the activation of OSMOSE sample in TAPIRO (AOSTA) campaign, under the aegis of the NEA Expert Group on Integral Experiments for Minor Actinide Management, is oriented to analyse the feasibility of a MAs irradiation campaign in the TAPIRO Italian fast source research reactor. The feasibility studies were carried out by calculations modeling the irradiation, in different TAPIRO irradiation channels, of some samples, supplied by CEA and coming from the French experimental campaign OSMOSE, containing different types and contents of MAs, to improve the knowledge on MAs capture cross sections. The OSMOSE sample series are enriched by AmO2 samples from IRMM (EC-JRC Institute for Reference Materials and Measurements), currently used in the AMSTRAMGRAM programme in MINERVE, as well as a complementary study of miniature fission chambers loaded with MA deposits for spectral indices measurements in tangential channels and in the thermal column. Another open issue is the need to figure out how the response of the MAs reaction rates, essentially capture, is linked to the TAPIRO copper reflector nuclear data. In this work, the sensitivity coefficients of some MAs capture rates to Cu cross section variations have been preliminary estimated by means of both generalised perturbation theory (GPT) and direct approach by deterministic calculations.