Hydraulic characteristics in secondary vessel of double pool LMFBR

CRIEPI made a conceptual design study on Metallic Fueled Double Pool LMFBR from 1990 to 1992. In this study, the configuration of the primary and the secondary vessel, and both arrangement and number of the secondary components were selected to realize the simplification of the structure. Flow field of the coolant in the secondary vessel is depend on this design. The objective of this study is to clarify the hydraulic characteristics in the secondary vessel by 1/7 model of water test and analysis and to confirm the validity of this design. Followings are main results. (1) As a result of the water test, it is confirmed that there is no stagnant region in the secondary vessel and there are sufficient mixing effect under steam generators. (2) As a result of the comparison between flow distribution obtained by water test and that by analysis, good agreements are obtained qualitatively. (3) There is no stagnant region near the free surface in the secondary vessel under reactor condition of normal operation. Therefore, a thermal stratification will not take place. Because of the mixing effect under SG outlet, it is considered that temperature of the coolant in the secondary vessel changes slowly in the case of transient condition Therefore the validity of the design is confirmed. (author)