THE PANDA FACILITY AND FIRST TEST-RESULTS

The PANDA test facility at the Paul Scherrer Institute is used to stud y the long-term performance of the Simplified Boiling Water Reactor's passive containment cooling system. The PANDA tests demonstrate perfor mance on a larger scale than previous tests and examine the effects of any non-uniform spatial distributions of steam and non-condensable ga ses in the system. The facility is in 1:1 vertical scale and 1:25 scal e for volume, power etc. Extensive facility characterization tests and steady-state passive containment condenser performance tests are pres ented. The results of the base case rest of a series of transient syst em behaviour tests are reviewed. The first PANDA tests exhibited repro ducibility, and indicated that the Simplified Boiling Water Reactor's containment is likely to be favorably responsive and highly robust to changes in the thermal transport patterns.