A preliminary study for the utilization of the TRIGA RC-1 research reactor as a facility for radiation damage

TRIGA RC-1 Mark II reactor of ENEA’s Casaccia Research Center reached its first criticality in 1960, with a maximum thermal power of 100 kW. In 1967 it was upgraded at the thermal power of 1 MW. Currently the core, fully reflected by graphite, contains 111 TRIGA standard SS cladded fuel elements (235U enrichment 19.90%, uranium weight fraction 8.5% of the UHZr alloy). The reactor is moderated also by demineralized light water, serving as first biological shield and coolant too. TRIGA RC-1 is equipped with various experimental channels and irradiation positions in-core and out of the core, providing a wide range of neutron and gamma fluxes and spectra useful for diverse applications. During 2017 an agreement was signed between ENEA and the Italian Spatial Agency to cooperate in the field of neutron/gamma radiation damage analysis on electronic components to be used in future space-crafts. This agreement provides for use ENEA TRIGA RC-1 (and TAPIRO) research reactors as tools to perform neutron/gamma irradiation on such electronic components. In the meantime, in the frame of other activities focused on the evaluation of the current TRIGA RC-1 fuel burn-up level, a MCNPX model of the reactor has been implemented and validated by means of a comparison between experimental and calculated neutron flux spectra for different core positions, starting from the first core loading in 1967. This paper describes the main steps moved up to now to characterize the facility neutron field and to evaluate some key ASTM(American Society for Testing and Materials)standard damage parameters, such as 1 MeV neutron equivalent flux and hardness parameter, using the MCNPX TRIGA RC-1 model. The description of the neutronic fields present in the available irradiation channels and facilities of TRIGA RC-1 to be used in the future experimental campaigns devoted to radiation damage analysis, always based on the results from the MCNPX model, completes the work described in this paper.