A Circuit Sodium Purification System Numerical Simulation Of A Large Break Accident

During routine operations of China Experiment Fast Reactor, there will be some sodium leakage accidents by any possibility. In order to guarantee its reactor safety, we must analyze these accidents through experiments and theory analyzing, then, we could grasp reliable data to control and avoid these accidents.This paper describes and analyses the sodium leakage accidents in the primary circuit of CEFR, especially in the curve pipelines of the primary sodium purification system when it suffers the double-ended guillotine break. In this curve pipeline system, an Argon-Sodium Two-phase Flow Analysis and Simulation Code for one dimensional and unsteady two fluid flowing in a bend pipe, also can be called THYMOS, was used to simulate the whole two-phase flow process of the Anti-Siphon equipment pipeline's leakage; calculate the corresponded parameters; and anatomize the effects with varieties of these parameters.In this model, separated continuity and momentum equations were used to calculate the parameters for each phase, field variables are stored in a staggered-grid fashion, and finite volume method was used to numerically resolve these equations. Compared to the experimental data, this model can correctly describe the phenomenon of leakage processes.Meanwhile, using these calculated results, this paper evaluated the ambient effects caused by these accidents. BOX and AERO codes mainly calculated ²²Na and ²⁴Na radioactive quantities, which are all significantly less than their prescriptive safety limits.