Thermal hydraulic transient study of 3 MW TRIGA Mark-II research reactor of Bangladesh using the EUREKA-2/RR code

Highlights: ► Reactor power transition time depends on magnitude and form of reactivity. ► This time also depends on existing reactor power during reactivity insertion. ► Pattern of power transition depends on form of reactivity insertion. ► Doppler's effect is seen for lower reactivity insertion when reactor power is low. ► EUREKA-2/RR code performs well for RIA and LOFA of TRIGA Mark-II research reactor. - Abstract: EUREKA-2/RR code has been used for the analyses of reactivity insertion accident (RIA) and loss of flow accident (LOFA) of 3 MW TRIGA Mark-II research reactor of Bangladesh. Transient characteristics of different parameters such as core power, fuel temperature, clad temperature, departure from nucleate boiling ratio (DNBR) due to the different form and magnitude of reactivity insertion has been focused. It is found from the analysis that the magnitude of insertion reactivity and the reactor operating power during this insertion impose a total effect on the core safety. Also, transient effects on reactor were studied for 15% loss of flow of the primary coolant. Provided the scram system is available, the reactor is found to shutdown safely in both cases. From these two studies in series, it is seen that EUREKA-2/RR is well suited for the analyses of reactor safety parameters with good approximations.