The development of fast neutron power reactors with a sodium coolant and ways in which their technical and economic performance can be improved

During the years that have elapsed since the commissioning of power units with fast neutron BN-350 reactors (1973) and BN-600 reactors (1980), considerable experience has been acquired in the operation of fuel elements, sodium equipment and mechanisms and steam generators. Operating experience has confirmed the reliability and safety of both types of facilities. Nevertheless, during the last few years a number of improvements have been introduced in the operating mode, in the equipment design solutions and in the system flow sheets. These solutions were aimed at further increasing the reliability, safety and profitability of the power units. The BN-800 reactor is based to a considerable extent on the scientific and technical ideas and design development of the BN-600 reactor. During its design, considerable attention was paid to developing reliable equipment which would ensure a higher level of fuel burnup than that of the BN-600 and to mastering the closed fuel cycle. The BN-1600 reactor constitutes a new step in the development and creation of a fast breeder reactor with sodium coolant. However, even in its design, the basic scientific and technical ideas developed for the BN-600 and BN-800 reactors were maintained to a considerable degree. The experience of developing and operating fast sodium cooled reactors in the USSR has confirmed the expected positive safety characteristics of this type of reactor. At the same time, there are significant reserves for further improving the safety characteristics and this does not present any major difficulties. (author). 5 refs, 1 fig., 4 tabs