Nuclear reactor channel modelling using the THMOD2 code

This paper presents preliminary results of the THMOD2 computer code and checks its validity using KFKI reactor fuel channel data as a sample problem for the application. The computer code has been developed to simulate the multi-passages reactor coolant channel and perform the necessary axial temperature distribution along the multi-passages channel, and other thermal hydraulics analysis for any Research Light Water Reactor (RLWS) coolant channel. The temperature criteria are such that the surface boiling should be avoided at any part of the cladding surface of the coolant channel. Comparing the results of the THMOD2 with the results recorded in the reactor safety report shows good agreement. Finally, the calculations of this code were performed at equilibrium state with maximum core loading and under steady state conditions. (orig.)