Calculation of the deterministic optimum loading pattern of the BUSHEHR VVER-1000 reactor using the weighting factor method

► In this study, weighting factor method and structural constraints were applied. ► Each fuel assembly bears a weight based on its characteristics and position. ► The applied method shortened the time consumed for achieving the deterministic optimized loading pattern. ► The computer codes WIMSD5-B, CITATION-LDI2 and COBRA-EN codes were used. ► The effect of temperature distribution has been considered in the neutronic calculations.