Composition Effects on the Vapor Hydration of Waste Glasses

Raman and X-ray absorption spectroscopic studies of hydrothermally altered alkali-borosilicate nuclear waste glass

“…6d) than the calculation for Na (1). These results probably indicate that most Na within this particular analcime sample is in the Na(2)-sites [8].…”

“…The two glasses investigated are part of a matrix of 12 simplified alkali-alumina-borosilicate glass compositions based on actual waste glass compositions developed to vitrify high-sodium, lowactivity nuclear waste (LAW) at the Hanford site [1]. The simplified matrix was designed to study variations in vapor hydration test (VHT (ASTM C1663)) durability [2,3] produced by alkali substitution (K for Na in two steps), and by successive additions of Fe, Mg, and Ca.…”

“…The simplified matrix was designed to study variations in vapor hydration test (VHT (ASTM C1663)) durability [2,3] produced by alkali substitution (K for Na in two steps), and by successive additions of Fe, Mg, and Ca. The two glasses studied here, Lo1A and Lo2A [1], were at the high-Na extreme of the test matrix, and have the same composition except that in Lo2A glass, the K 2 O concentration is increased at the expense of Na 2 O (Table 1). Data provided by testing such simplified glasses are useful as indicators of how similar variations in more complex actual waste-glass formulations will affect their VHT durability.…”

“…Phase identification of the crystalline standards: quartz (NMNH #R17669 from Hot Springs, Arkansas), analcime (NMNH #104655 from County Antrim, Ireland) and leucite (NMNH #167389 from Napoli, Italy), was verified by powder XRD. The Lo1A and Lo2A glasses used for this study were synthesized from reagent grade chemicals [1] and were confirmed to be crystal-free by XRD. The glass fragments were taken from homogeneous portions of the annealed melt material.…”

“…We thank Frank Lofaj (Vitreous State Laboratory) for preparation of the glasses [1] that were tested and characterized in this work. We also thank Jeffrey Post and Paul Pohwat (Mineral Sciences Department, Smithsonian Institution) for providing the quartz, analcime, and leucite crystals.…”