Preliminary assessment of modeling issues related to dynamics and control of graphite-moderated MSRs

The Molten Salt Reactor (MSR) is characterized by a complex physical environment, as a consequence of the unusual role of the molten salt, which acts simultaneously as fuel and coolant. Such unique feature requires the development of dedicated simulation tools, able to take into account peculiar phenomena of Circulating Fuel Reactors (CFR) such as the delayed neutron precursor (Dnp) drift and the subsequent decay out of the core. In this paper, reference is made to the Molten Salt Reactor Experiment (MSRE). The MSRE was an 8 MWth graphite-moderated MSR built at the Oak Ridge National Laboratory during the sixties. It represents a convenient validation framework due to the availability of both design and experimental data. The analysis is carried out by means of a dynamic model. All the main components of the experimental plant are simulated. On the basis of the available MSRE experimental data, the proposed model results sufficiently accurate to predict the plant response in terms of the most relevant variables. A preliminary analysis of the control strategy has been also carried out considering a reactor/slave radiator/master control, confirming this strategy as a safe and effective one