Title: Foaming during nuclear waste melter feeds conversion to glass: Application of evolved gas analysis

Abstract

Abstract During the final stages of batch‐to‐glass conversion in a waste‐glass melter, gases evolving in the cold cap produce primary foam, the formation and collapse of which control the glass production rate via its effect on heat transfer to the reacting batch. We performed quantitative evolved gas analysis (EGA) for several HLW melter feeds with temperatures ranging from 100 to 1150°C, the whole temperature span in a cold cap. EGA results were supplemented with visual observation of batch‐to‐glass transition using the feed expansion tests. Upon heating, most of the gases—mainly H ₂ O, CO ₂ , NO, NO ₂ , N ₂ , and O ₂ —evolve at temperatures below 700°C and escape directly to the atmosphere through open porosity. However, as open porosity closes when enough glass‐forming melt appears at ~720°C, the residual gas evolution leads to the formation of primary foam. We found that primary foaming is mostly caused by the decomposition of residual carbonates, though oxygen evolution from iron‐redox reaction can also play a role. We also show that the gas evolution shifts to a higher temperature when the heating rate increases. The implications for the mathematical modeling of foam layer in the cold cap are presented.

Authors:

Hujova, Miroslava  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-0876-7292"

Pokorny, Richard  ^[1];

• Search DOE PAGES for author "Pokorny, Richard"
• Search DOE PAGES for ORCID "0000-0002-9023-0381"

Klouzek, Jaroslav ^[1]; Lee, Seungmin ^[2]; Traverso, Joseph J. ^[2]; Schweiger, Michael J. ^[2]; Kruger, Albert A. ^[3]; Hrma, Pavel ^[2]

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+ Show Author Affiliations

1. Laboratory of Inorganic Materials Joint Workplace of the University of Chemistry and Technology Prague Prague Czech Republic, The Institute of Rock Structure and Mechanics of the ASCR, v.v.i. Prague Czech Republic
2. Pacific Northwest National Laboratory Richland WA USA
3. Office of River Protection U.S. Department of Energy Richland WA USA

Publication Date:

Wed Apr 18 00:00:00 EDT 2018

Sponsoring Org.:

USDOE

OSTI Identifier:

1433558

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

International Journal of Applied Glass Science

Additional Journal Information:

Journal Name: International Journal of Applied Glass Science Journal Volume: 9 Journal Issue: 4; Journal ID: ISSN 2041-1286

Publisher:

Wiley-Blackwell

Country of Publication:

United States

Language:

English