Title: Melter Feed Reactions at T  ≤   700°C for Nuclear Waste Vitrification

Abstract

To understand feed‐to‐glass conversion for the vitrification of nuclear waste, we investigated batch reactions and phase transitions in a simulated nuclear waste glass melter feed heated at 5 K/min up to 700°C using optical microscopy, scanning electron microscopy with energy‐dispersive X‐ray spectroscopy, and X‐ray diffraction. To determine the content and composition of leachable phases, we performed leaching tests; the leachates were analyzed by inductively coupled plasma atomic emission spectroscopy. By 400°C, gibbsite and sodium borates lost water and converted to amorphous phase, whereas other metallic hydroxides dehydrated to oxides. Between 400°C and 700°C, carbonates decomposed before 500°C; amorphous aluminum oxide and calcium oxide reacted with the sodium borate and formed the more durable amorphous borate phase along with intermediate crystalline products; above 500°C, quartz began to dissolve, and hematite started to convert to trevorite.

Authors:

Xu, Kai ^[1]; Hrma, Pavel ^[1]; Rice, Jarrett ^[1]; Riley, Brian J. ^[1]; Schweiger, Michael J. ^[1]; Crum, Jarrod V. ^[1]; Vance, ed., E.

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+ Show Author Affiliations

1. Pacific Northwest National Laboratory Richland Washington 99352

Publication Date:

Thu Jul 23 00:00:00 EDT 2015

Sponsoring Org.:

USDOE

OSTI Identifier:

1400519

Grant/Contract Number:  

DE‐AC05‐76RL01830

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Journal of the American Ceramic Society

Additional Journal Information:

Journal Name: Journal of the American Ceramic Society Journal Volume: 98 Journal Issue: 10; Journal ID: ISSN 0002-7820

Publisher:

Wiley-Blackwell

Country of Publication:

United States

Language:

English