Development of a thermal hydraulic code for an integral reactor

• Models developed for integral reactor with plate type fuels and OTSG.
• Good agreement between the developed code and RELAP5/Mod3 achieved.
• Developed code can successfully simulate the large disturbance dynamic processes.

The integral reactor has attracted much attention in recent years because of its enhanced natural circulation ability and good inherent safety feature. A thermal-hydraulic analysis code, following the modular and hierarchical principles, has been developed to study the transient performance of the integral reactor with the plate type fuel and once through steam generator. The reactor kinetics model, three region pressurizer model and special models for the plate type fuel and the once through steam generator have been proposed. The code is validated by comparing the results obtained by the new developed code to those calculated by RELAP5/Mod3. Both the steady state and the transient processes are simulated and the results present good agreement between the two codes. Several transient processes were simulated and the results show that the developed code can successfully simulate the dynamic processes in different load levels.