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Submixture model to predict nepheline precipitation in waste glasses
Author(s) -
Vienna John D.,
Kroll Jared O.,
Hrma Pavel R.,
Lang Jesse B.,
Crum Jarrod V.
Publication year - 2017
Publication title -
international journal of applied glass science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 34
eISSN - 2041-1294
pISSN - 2041-1286
DOI - 10.1111/ijag.12207
Subject(s) - nepheline , nepheline syenite , materials science , precipitation , ternary operation , radioactive waste , crystallinity , mineralogy , high level waste , chemical engineering , nuclear chemistry , geology , chemistry , composite material , physics , meteorology , computer science , programming language , engineering
High‐alumina high‐level waste ( HLW ) glasses are prone to nepheline precipitation during canister‐centerline cooling ( CCC ). If sufficient nepheline forms, the chemical durability of the glass will be significantly impacted. Overly conservative constraints have been developed and used to avoid the deleterious effects of nepheline formation in U.S. HLW glasses. The constraints used have been shown to significantly limit the loading of waste in glass at Hanford and therefore the cost and schedule of cleanup. A 90‐glass study was performed to develop an improved understanding of the impacts of glass composition on the formation of nepheline during CCC . The CCC crystallinity data from these glasses were combined with 657 glasses found in the literature. The trends showed significant effects of Na 2 O, Al 2 O 3 , SiO 2 , B 2 O 3 , CaO, Li 2 O, and potentially K 2 O on the propensity for nepheline formation. A pseudo‐ternary submixture model was proposed to identify the glass composition region prone to nepheline precipitation. This pseudo‐ternary with axes of SiO 2 + 1.98B 2 O 3 , Na 2 O + 0.653Li 2 O + 0.158CaO, and Al 2 O 3 was found to divide glasses that precipitate nepheline during CCC from those that do not. Application of this constraint is anticipated to increase the loading of Hanford high‐alumina HLW s in glass by roughly one‐third.