Thermo-Hydraulic Calculation and Safety Analysis of the Tehran Research Reactor

The aim of this study is to evaluate the thermal hydraulic parameters such as, Minimum DNBR, fuel, clad and coolant temperatures of the Tehran Research Reactor (TRR) core in order to assure that the thermal limitations are not exceeded at full power and steady-state and the loss-of-flow accident (LOFA) operating conditions and the existing design is adequate to assure that the consequences from this anticipated occurrence does not lead to a severe accident. The PARET and TRANS computer codes were used to analysis thermal-hydraulic and safety parameters under study steady-state conditions. Furthermore the LOFA as a consequence of two type of transients are analyzed; one related to main cooling pump failure accident (slow LOFA), and the other related to accidentally opening the flapper valve whereas the main cooling pump is in working (fast LOFA). The steady-state analysis involves the determination of the departure from nucleate boiling ratio (DNBR), the temperatures profile, heat flux across the hottest channel and etc. The LOFA analysis involves the power and coolant flow rate, the fuel centerline, clad surface and coolant outlet temperatures, and the occurring of coolant flow reversal.