Study on mechanism of pressure fluctuation in a primary circuit hot-leg pipings of a sodium-cooled fast reactor

Murakami, Takahiro*; Eguchi, Yuzuru*; Tanaka, Masaaki  ; Yamano, Hidemasa   

In a conceptual design of Japan Sodium-cooled Fast Reactor (JSFR), short-elbow pipings with large-diameter are adopted for cooling system, in which the coolant flow causes periodical pressure fluctuation at the short-elbow. However, the mechanism of the periodical pressure fluctuation has not been clarified yet. In this paper, unsteady three-dimensional analysis by a finite element large-eddy-simulation (LES) code is carried out in order to explore the mechanism of the periodical pressure fluctuation in short-elbow pipings, based on visualizations of dynamic flow structure in the numerical results.