Design of Single-Input Fuzzy Logic Controller for Spatial Control of Advanced Heavy Water Reactor

In large nuclear reactors, such as the Advanced Heavy Water Reactor (AHWR), the spatial oscillations in the neutron flux distribution due to xenon reactivity feedback need to be properly controlled; otherwise, power density and rate of change of power at some locations in the reactor core may exceed limits of fuel failure due to “flux tilting.” Further, situations, such as online refueling, might cause transient variations in the flux shape from the nominal flux shape. For analysis and control of spatial oscillations in AHWR, it is necessary to design a suitable control strategy, which will be able to stabilize these oscillations. In this paper, a simplified scheme to design a fuzzy logic controller for spatial control of AHWR, known as the single-input fuzzy logic controller (SIFLC) is proposed. The SIFLC reduces the conventional two-input fuzzy logic controller (CFLC) to a single-input FLC. The SIFLC offers a significant reduction in rule inferences and simplifies the tuning of control parameters. The SIFLC requires less execution time compared to CFLC for the control of spatial oscillations in AHWR. Through the dynamic simulations, it is observed that the designed SIFLC is able to suppress spatial oscillations developed in AHWR and the performance is found to be better compared to the recently proposed approach in the literature.