Transient pressure propagation behavior in PbLi loop system triggered by in-box LOCA accident of DFLL blanket

For a liquid metal blanket such as Dual-Functional Lithium Lead (DFLL) blanket, in-box LOCA not only causes pressurization in breeder box, but also propagates transient high pressure to Lithium Lead (PbLi) loop system. Similar to the water hammer effect in the coolant loop of a fission power plant, a high pressure wave in PbLi loop might damage components and threaten the integrity of loop structure.

In this paper, the 3D Computational Fluid Dynamics (CFD) code FLUENT was coupled with the systems code RELAP5/MOD4.0 to simulate pressure propagation behavior triggered by an in-box LOCA accident in the PbLi loop system of a DFLL blanket. Reflection and superposition of the pressure wave in complex channels of a DFLL blanket module were accurately simulated with FLUENT, and propagation of pressure waves in the PbLi loop system was simulated by RELAP5 code.