Abstract
This paper presents the results of POLCA-T code validation against an analytical solution at flow oscillating conditions. The POLCA-T code is a coupled computer code with 3D neutron-kinetics and thermal-hydraulics. Best estimate reactor analysis codes of this type incorporate a full 3D model of a reactor core into a system transient code. The coupled code provides a means to simulate interactions between reactor core behavior and plant dynamics. This validation paves the way for further code validation against cases with flow oscillating phenomena. Furthermore, the analytical test case provides a check for both the appropriate implementations of numerical methods and that the solution is not affected by their implementation. Moreover, a justification to minimize the error is also made by investigating the theta factor, Θ, in the time integration of mass conservation, energy and momentum equations. The comparison shows that the POLCA-T results and the analytical solution are almost identical. The effect from different time steps is very limited, when the time step changes a factor of 10. The results are most sensitive to the choice of parameter, Θ, for the numerical time integration method
