Evaluation of Crystal Accumulation in High Level Waste Glasses with Research-Scale Melter

Technical Report · Wed Apr 11 04:00:00 EDT 2018

DOI:https://doi.org/10.2172/1868935· OSTI ID:1868935

Matyas, Josef ^[1]; Sevigny, Gary J. ^[1]; Venarsky, John J. ^[1]; Davis, James M. ^[1]; Lukins, Craig D. ^[1]; Lang, Jesse B. ^[1]; Edwards, Matthew K. ^[1]; Stewart, C M. ^[1]; Sannoh, Sulaiman E. ^[1]; Veldman, Timothy G. ^[1]; Phillips, Nathan R.J. ^[1]; Fischer, Christopher M. ^[1]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

The report summarizes the experimental results from a long term Research Scale Melter (RSM) test which was performed at Pacific Northwest National Laboratory (PNNL) in FY16 to answer questions on the effects of spinel crystal accumulation on melter performance and operational longevity. The RSM was used to vitrify a surrogate waste material of the Hanford AZ-101 tank waste composition. This waste contains a high concentration of Fe and Ni and is susceptible to precipitation of a large quantity of spinel crystals during vitrification. The RSM test was run over a period of 11 weeks and consisted of eleven feeding/pouring and idling periods. The feeding/pouring periods were 36 h long while the idling periods ranged from 4 to 7 days. Approximately 509 kg of feed was processed, producing ~159 kg of glass. The main goal of this test was to determine if the riser of the melter can be clogged by accumulated layer of spinel crystals which precipitated from glass during multiple idling’s. In addition, the glass samples were collected during each pouring to evaluate a possibility of a partial or complete removal of crystal deposits accumulated during idling. Furthermore, an electrical conductivity probe was tested for monitoring the crystal accumulation in the riser of the melter during idling’s. The test was concluded by dissecting the melter and preparing cross-sections to determine layer thickness, crystal size and morphology of spinel crystals in the bulk of the melter and in the glass riser.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1868935
• Report Number(s): PNNL-27419
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
Accumulation
Electrical conductivity probe
Research-scale melter
Spinel crystals
Vitrification