Non-dimensional analysis of the transient flow rate and the coolant temperature in a reactor coolant system under different pump failures

Abstract

ABSTRACTThe mathematical models are developed to solve the non-dimensional transient flow rates in two loops and a reactor core under different power failures of reactor coolant pumps. Comparison of the experimental results of the Qinshan Nuclear Power Plant and the test results of the nuclear ship reactor in Japan under one pump power failure shows an excellent agreement. The non-dimensional flow rates are determined by the established non-dimensional parameters λ, ϵ, and α. Under the sequential power failure of two pumps, the non-dimensional flow rates are determined by the established λ, ϵ, α, and ΔT parameters. λ, ϵ, α, and ΔT are four important non-dimensional parameters in the prediction of flow transients. λ indicates the resistance coefficient ratio of the single loop to the reactor core, ϵ indicates the fluid inertia ratio of the reactor core to the single loop, α indicates the ratio of the initial kinetic energy of the single loop coolant fluid to the effective initial kinetic energy of the reactor coolant pump, and ΔT means the non-dimensional time interval of the sequential power failure of two pumps. The effects of λ, ϵ, α, and ΔT on the non-dimensional flow rates and the temperature change are investigated.