Effect of Technetium-99 sources on its retention in low activity waste glass

Journal Article · 01 March 2018 · Journal of Nuclear Materials

DOI: https://doi.org/10.1016/J.JNUCMAT.2018.02.019 · OSTI ID:1425497

Luksic, Steven A. ^[1]; Kim, Dong Sang  ^[1]; Um, Wooyong ^[1]; Wang, Guohui ^[1]; Schweiger, Michael J. ^[1]; Soderquist, Chuck Z. ^[1]; Lukens, Wayne  ^[2]; Kruger, Albert A. ^[3]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
3. USDOE Office of River Protection, Richland, WA (United States)

Small-scale crucible melting tests on simulated waste glass were performed with technetium-99 (Tc-99) introduced as different species in a representative low activity waste simulant. The glass saw an increase in Tc-99 retention when TcO₂∙2H₂O and various Tc-minerals containing reduced tetravalent Tc were used compared to tests in which pertechnetate with heptavalent Tc was used. Here, we postulate that the increase of Tc retention is likely caused by different reaction paths for Tc incorporation into glass during early stages of melting, rather than the low volatility of reduced tetravalent Tc compounds, which has been a generally accepted idea. Finally, additional studies are needed to clarify the exact mechanisms relevant to the effect of reduced Tc compounds on Tc incorporation into or volatilization from the glass melt.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC05-76RL01830; AC02-05CH11231; AC02-76SF00515
• OSTI ID: 1425497
• Report Number(s): PNNL-SA--125641; PII: S0022311517311261
• Journal Information: Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Vol. 503; ISSN 0022-3115
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English