10 years after criticality of ATR 'Fugen' and its technological achievement

The prototype ATR 'Fugen' attained the criticality in March, 1978, as a power reactor charged with uranium-plutonium MOX fuel for the first time in the world, and through the operation of 10 years thereafter, the technology of plutonium utilization and the system engineering of ATR type reactors have been verified, moreover, the improvement and development of the technologies have been positively promoted. This technological achievement is reflected to the design of a demonstration ATR carried out by Electric Power Development Co. The main achievement obtained by the operation of Fugen is shown. Fugen is a heavy water-moderated, boiling light water-cooled, pressure tube type reactor of 557 MWt and 165 MWe, and fuel exchange has been carried out twice every year. In the core, the moderator and the coolant are separated with pressure tubes and a calandria. The core characteristics, the result of irradiation of MOX fuel and its irradiation characteristics, the plant characteristics, the techniques of handling heavy water, the irradiation characteristics of pressure tubes, the development of operation and maintenance techniques and the operation management techniques are reported. (Kako, I.)