An Experimental Study of a Flashing-Driven CANDU Moderator Cooling System

Abstract

The results of un experimental study to investigate the feasibility of using a passive flashing-driven natural circulation loop for CANDU-reactor moderator heal rejection are presented. A scaled loop was constructed and tested at conditions approximating those of a CANDU calandria cooling system. The results showed that stable loop operation was possible at simulated powers approaching normal full power. At lower powers, flow oscillations occurred as the flow in the hot-leg periodically changed from two-phase to single-phase. The results from earlier numerical predictions using the CATHENA thermalhydraulics code showed good qualitative agreement with the experimental results.