Özet:
In this work the thermal-hydraulic programroes TERHID, which makes steady state and transient thermal-hydraulic analysis for plate type nuclear fuel elements , and COBRA 111-C, a computer programme for steady state and transient state therma l-hydraulic analysis of rod bundle fuel elements with subchannel approach analysed and compared. The comparison of the two programmes cover the anslysis of the conduction and the convection models, the assumptions made in the models , and the solution algorithms . The numerical applications consist of two parts. In the first part the sample problem given in TERBID is applied as input to COBRA 111-C. The transient solutions for different time increment are intercompared for this programme. In these condpart another applictaion is carried out for the identical problem using both codes by considering the effect of the inlet temperature change, inlet mass flux change and power change as a function of time during transients.