[en] A mockup experiment was conducted to simulate a loss-of-coolant incident in the K-West reactor. The mockup assembly included a K-Reactor Zircaloy-2 process tubing with a KVN aluminum-clad metallic uranium fuel element. The assembly was induction heated to 850⁰C in flowing steam environment. Bloating of the element occurred. The friable Al/U reaction product and the surface of the U core were not pyrophoric, even under abrasion. However, the mockup assembly was not subjected to hydrogen and water vapor. The Zircaloy-2 tube showed evidence of embrittlement along the bottom. Accelerated corrosion and hydriding also occurred near the six o'clock position. The core was removed easily from the Zircaloy-2 tube. Steam corrosion of the U core was not obvious from metallography, and hydrogen contents were minimal. Metallography of the U core indicated remnants of the Al/U reaction layer adhering to the OD and ID surfaces. The reaction product appeared to be two-phase, probably UAl₃ and eutectic. Reactions of Zircaloy-2 in molten 8001 aluminum were investigated at 850⁰C. After an induction period (approx. 5 min), the penetration rate was 2.7 mil/min (as-etched). Oxides of 85 mg/dm² (5 x 6 microns) delayed the reaction only 3.5 min