[en] In order to have the market opportunity in the nuclear industry in both terms of competitive environment of demand and chances for supply in other word export, the study and development of CANDU reactor are of quite importance. Series of studies have been made for enhancing the safety and performance of CANDU reactor. Among them, we have been developed an experimental method to identify the flow patterns of moderator circulation in the Calandria Tank of the CANDU reactor. As reported we have developed a scaling method based on the jet force and buoyancy force in the medium and finally developed 1/8 scale facility