Study on diffusion and natural circulation of two component gases. (1st Report, Experiment and analysis with a reverse U-shaped pipe).

Abstract

When a primary coolant pipe of a high temperature gas-cooled reactor (HTGR) ruptures, air is expected to ingress into the reactor core from the broken part by natural circulation and diffusion. In order to study the basic features of the air ingress during the early stage of the primary pipe rupture accident in a high temperature gas-cooled reactor, the conjugate problem of natural circulation and diffusion of the He-N2 two-component gas was studied experimentally and analytically. The study was performed on the phenomenon in a reverse U-shaped round pipe with one pipe heated and the other cooled. The analytical and experimental results were in good agreement on gas concentration change in the tube and initiation time of natural circulation of N2 single component gas.