Scaling analysis for inertia tank based on the cold state of deep pool-type nuclear heating reactor

Highlights: • The scaling laws for inertia tank are derived based on the cold state of DHR-400. • Two ideal scaled models are designed and assessed by RELAP5/MOD3.3. • The ideal scaled model 2 shows better performance. Inertia tank is a potential device to replace the flywheel of main pump in the deep pool-type nuclear heating reactor (DHR-400), which can maintain the cooling of reactor core after the failure of main pump power. Based on the cold state of DHR-400, the governing equations are derived for the working process of inertia tank, and then the scaling laws are obtained by the dimensionless governing equations. According to the scaling laws, two ideal scaled models are designed with different scaling ratios. And RELAP5/MOD3.3 is used to assess the scaling of ideal scaled models. The results show that the transient characteristics of DHR-400 can be highly replicated by ideal scaled models and the maximum relative errors of mass flow and liquid level are 9.36% and 1.54%, respectively. In addition, the time scaling ratio between the ideal scaled models and prototype is equal to the square root of length scaling ratio.