Recent Simulations of the Distribution of Flow and Temperature in Horizontal Bundles Using ASSERT-4

Abstract

The ASSERT subchannel code has been developed specifically to model flow and phase distributions within CANDU fuel bundles. ASSERT uses a drift-flux model, which permits the phases to have unequal velocities, and thus can model phase separation tendencies which may occur in horizontal flow. This paper summarizes the non-equilibrium models used in the ASSERT code, the equations used to represent these models, and the algorithms used to solve the equations numerically. The paper gives some results from recent validation exercises and mentions new developments in the code leading to the current production version of ASSERT-4, Version 2 Revision 3. This work was funded by the COG program FCCP Working Party.