Feasibility study of design of control rods for precise reactor power regulationMarro Amador, Alejandro (Avtor) Žerovnik, Gašper (Mentor) Suikkanen, Heikki (Komentor) Reactor physicsneutron fluxfission rateMonte Carlo methodSerpent codecontrol rodsneutron absorberfission rate ratio.An innovative design of low-absorption control rods has been proposed for power regulation of a nuclear reactor operating in a load-following mode. Control rods for power regulation contain materials with lower absorption cross sections and lower reactivity worth than regular, shutdown ‘black’ control rods and are intended to be inserted over the entire height. These control rods clusters with different reactivity worths have been designed to study their feasibility. A 2D model representing a typical PWR reactor core has been created using Monte Carlo Serpent code. The temperature defect has been calculated from HZP to HFP to define the reactivity worth requirements that need to be fulfilled by the control rods assemblies. Different designs have been developed as well as their geometrical configuration in the core. Local effects of CRA such as its position, the inserted reactivity worth, the concentration of neutron absorber materials, etc. were studied. These play an important role in the design of a control rods system since they affect important reactor parameters in a significant way. Radial power distribution has been studied to evaluate possible perturbations of the neutron flux on a local scale. Regarding the neutron flux distribution it can limit the effect of the CRA for certain positions of the core and therefore needs to be compensated. In addition, attempts have been made to minimize the interference effect between the control rod clusters. These were analysed in detail and found to be still large to implement this design in a reliable control rods system.20232023-12-15 08:15:03Magistrsko delo/naloga153038sl