Experimental verification on the integrity and performance of the passive residual heat removal system for a SMART design with VISTA-ITL

• Performance of the passive residual heat removal system.
• Thermal–hydraulic behavior during the steady state operation of the PRHRS.
• Natural circulation flow rate.
• Small-break loss of coolant accident.

The purpose of this paper is to verify the integrity and performance of the passive residual heat removal system (PRHRS) for the SMART design during a steady state condition. The system’s overall thermal–hydraulic behavior during the steady state operation of the PRHRS of the SMART reactor was simulated using the VISTA-ITL, a small-scale integral effect test loop for the SMART design. The PRHRS is operated properly when the reactor is shutdown considering all the operating conditions of the SMART plant. The steady-state PRHRS performance tests are divided into three conditions of 100% scaled power, 20% scaled power, and hot standby condition. The experimental results show that PRHRS’s integrity and performance are proper for these three conditions. The steady state condition was well operated to satisfy the initial test conditions presented in the test requirement, and its boundary condition was properly simulated. The natural circulation flow rate in the primary system was about 10.0%, 10.6%, and 10.6% for 100% scaled power, 20% scaled power, and hot standby condition, respectively. The PRHRS’s natural circulation flow was formed as much as 10.1%, 11.7% and 9.1% for 100% scaled power, 20% scaled power and hot standby condition of its nominal value in the early stage of the PRHRS operation, respectively.