At the ENEA TRIGA research reactor (Casaccia Research Center, Rome), a new neutron collimator has been designed and installed at the neutron tangential channel. This collimator, that is part of a neutron/X-ray facility for NDT analysis, was experimentally characterized and optimized in terms of thermal neutron flux, its spatial/energetic distribution, photon air KERMA and effective beam diamete...

When a nuclear power plant is in shutdown conditions for refuelling, the reactor coolant system water level is reduced. This situation is known as mid-loop operation, and the residual heat removal (RHR) system is used to remove the decay power heat generated in the reactor core. In mid-loop conditions, some accidental situations may occur with not a negligible contribution to the plant risk, an...

We discuss the stabilization of a class of nonlinear systems describing the dynamics of a stirred tank chemical reactor. The stabilization is achieved using linear dynamic feedback. Several types of controllers are defined for which closed loop global asymptotic stability of the set point can be proved. We also discuss the case where the closed loop possesses several equilibrium states and the ...

In this paper a detailed model of a VVER1000 reactor pressure vessel (RPV) with the extension of simplified primary loops is presented (Loop model). The primary loop components like steam generators and pumps are modelled by the outer shapes and additional source terms for energy and momentum exchange. The RPV model part is tested without primary loops and compared with former results obtained ...

Abstmct-This paper concerns the synthesis of dynamic output feedback controllers for minimum-phase nonlinear processes. The problem is addressed first for open-loop stable and then for general minimumphase nonlinear processes, leading to oneand two-degree-of-freedom controllers, respectively. The synthesis of the controllers essentially Involves combination of state feedback and state observers...

This study compared the solar energy utilization of a closed microalgae-based bio-loop for energy efficient production of biogas with fertilizer recovery against that of a stand-alone photovoltaic (PV) system. The comparison was made from the perspective of broad life cycle assessment, simultaneously taking exergy to be the functional unit. The results indicated that the bio-loop was more envir...

Taking inventories in reactor cores is critical for understanding their radioactive source terms and establishing the relationship between activity concentration primary loop status of core’s fuel. However, there a niche which simple but accurate conditions nuclide can reliably predict fission gas activities core loop. In this study, efficient model called “Inventories Point Reactor Fission Gas...