Steam chemical reactivity of Be pebbles and Be powder

This paper reports the results of chemical reactivity experiments for Be pe bbles (2 and 0.2 mm diameter) and Be powder (14-31 mum diameter) exposed to steam at elevated temperatures, 350-900 degreesC for pebbles and 400-500 d egreesC for powders. We measured BET specific surface areas of 0.12 m(2)/g for 2 mm pebbles, 0.24 m(2)/g for 0.2 mm pebbles and 0.66-1.21 m(2)/g for B e powder samples. These experiments showed a complex reactivity behavior fo r the material, dependent primarily on the test temperature. Average H-2 ge neration rates for powder samples, based on measured BET surface areas, wer e in good agreement with previous measurements for fully dense consolidated powder metallurgy (CPM)-Be. Rates for the Be pebbles, based on measured BE T 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. (C) 2000 Elsev ier Science B.V. All rights reserved.