Evidence of technetium and iodine release from a sodalite-bearing ceramic waste form
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
We proposed sodalites as a possible host of certain radioactive species, specifically 99Tc and 129I, which may be encapsulated into the cage structure of the mineral. To demonstrate the ability of this framework silicate mineral to encapsulate and immobilize 99Tc and 129I, single-pass flow-through (SPFT) tests were conducted on a sodalite-bearing multi-phase ceramic waste form produced through a steam reforming process. We produced two samples made using a steam reformer samples using nonradioactive I and Re (as a surrogate for Tc), while a third sample was produced using actual radioactive tank waste containing Tc and added Re. One of the non-radioactive samples was produced with an engineering-scale steam reformer while the other non-radioactive sample and the radioactive sample were produced using a bench-scale steam reformer. For all three steam reformer products, the similar steady-state dilute-solution release rates for Re, I, and Tc at pH (25 C) 9 and 40 C were measured. However, it was found that the Re, I, and Tc releases were equal or up to 4.5x higher compared to the release rates of the network-forming elements, Na, Al, and Si. Moreover, the similar releases of Re and Tc in the SPFT test, and the similar time-dependent shapes of the release curves for samples containing I, suggest that Re, Tc, and I partition to the sodalite minerals during the steam reforming process.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Management (EM)
- Grant/Contract Number:
- AC05-00OR22725; AC06-76RLO 1830
- OSTI ID:
- 1265816
- Alternate ID(s):
- OSTI ID: 1249912
- Journal Information:
- Applied Geochemistry, Vol. 66, Issue C; ISSN 0883-2927
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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