In order to solve the test verification problem of passive core makeup system(PCMS)design under marine conditions,this study takes the branch of core makeup tank(CMT)as an example to identify the thermal hydraulic phenomena of PCMS under marine conditions.Based on the hierarchical two-tiered scaling(H2TS)analysis method,scaling analysis is conducted for the identified key thermal hydraulic phenomena,and the similarity criteria for scaled PCMS design are obtained.The results show that there are various complex thermal hydraulic phenomena and their coupling processes in PCMS,among which the thermal hydraulic phenomena of CMT branch are the most representative,and its natural circulation process is most significantly affected by ocean conditions.The ocean conditions lead to additional inertia force on the fluid in PCMS system,and the consistent additional acceleration is a necessary condition for the experimental model to reproduce the influence of ocean conditions.The scaling design of core makeup system under ocean conditions should follow similarity criteria such as resistance number,Richardson number,condensation number and acceleration.The test model designed based on these similarity criteria can reproduce the key thermal hydraulic phenomena and their coupling effects in the prototype with reasonable distortion level.
Scaling analysisMarine conditionsSmall modular reactorCore makeup system