Steam Chemical Reactivity of Be Pebbles and Be Powder

This paper reports the results of chemical reactivity experiments for Be pebbles (2-mm and 0.2-mm diameter) and Be powder (14–31 μm diameter) exposed to steam at elevated temperatures, 350 to 900°C for pebbles and 400 to 500°C for powders. We measured BET specific surface areas of 0.12 m²/g for 2-mm pebbles, 0.24 m²/g for 0.2-mm pebbles and 0.66 to 1.21 m²/g for Be powder samples. These experiments showed a complex reactivity behavior for the material, dependent primarily on the test temperature. Average H₂ generation rates for powder samples, based on measured BET surface areas, were in good agreement with previous measurements for fully-dense CPM-Be. Rates for the Be pebbles, based on measured BET surface areas, were systematically lower than the CPM-Be rates, possibly because of different surface and bulk features for the pebbles, especially surface-layer impurities, that contribute to the measured BET surface area and influence the oxidation process at the material surface.