0

Full Content is available to subscribers

Subscribe/Learn More  >

Inductive Cold Crucible Melting and Characterization of Uranium and Thorium Bearing Murataite Ceramics

[+] Author Affiliations
O. A. Knyazev, A. G. Ptashkin, S. V. Stefanovsky, M. A. Zen’kovskaya, O. I. Stefanovsky

SIA Radon, Moscow, Russia

S. V. Yudintsev, B. S. Nikonov

IGEM RAS, Moscow, Russia

Paper No. ICEM2007-7126, pp. 1047-1053; 7 pages
doi:10.1115/ICEM2007-7126
From:
  • The 11th International Conference on Environmental Remediation and Radioactive Waste Management
  • 11th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B
  • Bruges, Belgium, September 2–6, 2007
  • Conference Sponsors: Nuclear Division and Environmental Engineering Division
  • ISBN: 978-0-7918-4339-0 | eISBN: 0-7918-3818-8
  • Copyright © 2007 by ASME

abstract

Murataite-based ceramics containing 10 wt.% either UO2 or ThO2 were produced by inductive cold crucible melting (ICCM) at operating frequencies of 1.76 MHz and 5.28 MHz and examined using X-ray diffraction and scanning and transmission electron microscopy. High specific productivity was achieved. Average melting ratio was 8.3 kW×h/kg. We identified three distinct murataite polytypes in the U-bearing ceramics: a five- (5C), eight- (8C), and three-fold (3C) fluorite unit cell composing respectively the core, intermediate and rim zones of the grains. In contrast, in the Th-bearing ceramic one of the polytypes with eight-fold (8C) fluorite unit cell was found to be prevailing over two others (5C and 3C). Computer simulation of the major reflection due to the murataite phase in the Th-bearing sample also exhibits superposition of peaks due to three distinct polytypes but one of them (8C) is predominant. The core zone of the murataite in the U-bearing specimens is characterized by UO2 concentrations as high as 12.1 wt%, which successively diminishes in concentration through the intermediate zone to the rim, the latter of which contains 5.2 wt% UO2 . Thorium distribution within the murataite crystals is more uniform. The other phases found in the ceramics are crichtonite, rutile and traces of perovskite, Fe/Mn titanate ilmenite/pyrophanite, zirconolite, and vitreous phase. The difference in phase composition and actinide partitioning in the ceramics is influenced by synthesis conditions. Thus, application of large-scale cold crucibles is a prospective route for the development of industrial-scale process and technology for ceramization of actinide-bearing HLW. The advantage of this method is production of zoned crystals with the highest concentrations of actinides and rare earth elements in the core, effectively isolating these elements from potential leach solutions.

Copyright © 2007 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In