Abstract Indonesia requires a long-lived nuclear reactor as part of its sustainable energy strategy, and this objective can be achieved through the modified CANDLE reactor. In this study, an assembly model with reflective boundary conditions was developed using the OpenMC code. The reactor core was modeled axially into six regions, each measuring 25 cm. The (U, Pu)N fuel was applied exclusively to the first and second regions, while the remaining regions consisted of natural uranium. This analysis investigates the influence of fuel rod configurations and power variations on reactor performance, focused on a single assembly under the aforementioned boundary conditions, in which neutrons reaching the boundary are not permitted to escape the system but are instead reflected back into the assembly volume being modeled, thereby eliminating neutron leakage. The simulation configuration employing 250 active batches, 50 inactive batches, and 20,000 particles was capable of achieving a standard deviation of 0.027 %. A 169-pin configuration was employed for the power variation study. Power levels of 1,632.7 kW and 1,959.2 kW yielded burnup levels of 240 and 308 GW d/T, with average power densities of 33 and 39 W/cm 3 , respectively, and peak power factor (PPF) values approaching unity. These findings provide a preliminary characterization of neutron behavior and the neutronic feasibility of the modified CANDLE design, analyzed within an assembly under reflective boundary conditions, serving as an initial step prior to its implementation and analysis in a full reactor core.
Angelina et al. (Tue,) studied this question.