Activities at TRIGA RC-1 ENEA Research Reactor

TRIGA Mark II reactor of ENEA’s Casaccia Research Center (in Italy named RC-1) 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 fuel elements. The reactor is moderated by demineralized water, which serves also as first biological shield and coolant. Heat produced by the core is removed by natural convection. In this paper we describe the upgrade of the instrumentation, equipment and experimental devices, the implementation of a TRIGA RC-1 dynamic model and of a MCNP model for the evaluation of the fuel elements burnup. Since the first core configuration at the operating power of 1MW, labeled 38, a great amount of data regarding, among other things, critical configurations, measured flux and control rods calibration have been collected. To supply a more accurate database on the fuel element burnup values, and with the aim of integrate a TRIGA RC-1 internal procedure, based on the total power generated, computer codes such as MONTEBURNS and MCNP5 will be used in the next future. Moreover a dynamic model dedicated to the simulation of the reactor dynamic behavior is described: in particular the model simulates operational transients, alarm situations followed by scram or shut-down operational phases, criticality incidents and instantaneous water loss. The model is validated on experimental data regarding low and full power reactor tests, operation of the reactor in normal and incidental conditions, in this last case in accordance with TRIGA RC-1 SAR evaluations. Control rods calibration and Xenon reactivity data complete the validation of the model. Finally, considering operation and maintenance activities, the paper describes modernization of instrumentations in the control room and the installation of a new irradiation facility in the shielded tank.