Some neutron-physical aspects of improving the fuel utilization in the WWER and RBMK water cooled thermal power reactors

From the analysis of neutron balance in the WWER and RBMK water cooled reactors the role of various neutron-physical characteristics of fuel lattices in the reduction of natural uranium consumption the UO2 fuel is replaced by the uranium fuel with increased density is shown. Quantitative relation between neutron balance components, conversion ratioes and natural uranium requirements for WWER and RBMK in closed fuel cycles is obtained. The conclusion is drawn that the main reserves for improving the utilization in the existing UO2 reactors consist for WWER in reduction of neutron losses in control elements and in the process of leakage from the reactors (use of efficient absorbers, breeding blankets whereas fo RBMK - in the reduction of harmful absorption mainly at the expense of the reduction of the quantity of structural materials