Data for: Preliminary Interpretative Analysis of the QUENCH-18 bundle test using SCDAPSim/mod3.5

The attached slides illustrate the post-test findings of the QUENCH-18 experiment: 1. Moderate pre-oxidation to ≈80 µm of oxide layer. 2. During the starvation period about 100 and 450 g oxygen and steam were consumed. During the steam consumption period about 45 g hydrogen were released. In the same period the partial consume of nitrogen (about 120 g) was registered. 3. Initiation of reflood with 50 g/s water caused strong temperature escalation to about 2450 K at elevations between 750 and 1150 mm. As result, about 238 g hydrogen were released (128 g for QUENCH-16). During re-oxidation of zirconium nitrides more than 54 g nitrogen were released. 4. Zirconium nitrides were formed inside zirconium oxide degraded under steam/oxygen starvation conditions. 5. Observations of bundle at elevations between 1300 and 1400 mm showed spalling of strongly oxidized cladding segments from rods. No remaining nitrides or nitrides re-oxidized during reflood were indicated at these upper elevations. Probably, they were dissolved by relocated melt.