Glass-contact refractory of the nuclear waste vitrification melters in the United States: a review of corrosion data and melter life

ABSTRACT

The performance of the refractory lining in glass melters used for nuclear waste vitrification is critical to the melter reliability for long-term continuous operation. Monofrax® K-3, a high Cr₂O₃ fused cast refractory material, has been widely used to build the liners of nuclear waste glass melters in the United States. Corrosion behaviour of Monofrax® K-3 refractory has been evaluated based on crucible-scale testing, inspection of the refractory components following scaled melter testing, and inspections of the Defense Waste Processing Facility (DWPF) melter refractory after service. The literature generally consists of empirical models based on short-term testing to describe refractory corrosion dependence on glass composition. Corrosion data from tests with longer testing times, at various temperatures, in the presence of molten salts, and with different redox reactions in the plenum atmosphere exist, may be insufficient to provide accurate refractory service life estimates. Additionally, the corrosion data collected under actual and scaled melter operating conditions are limited. Recommendations to achieve more direct correlation between the laboratory refractory corrosion data predictions and the observed melter service life are discussed to allow for more accurate predictions of the useful life of melter refractory linings.

KEYWORDS:

• Refractory
• nuclear waste
• glass melter
• corrosion
• waste treatment
• vitrification
• glass property model
• glass formulation

Acknowledgements

The authors would like to thank Pavel Hrma of AttainX, Support Services Contractor to the Office of River Protection, U.S. Department of Energy and Chris Chapman of Pacific Northwest National Laboratory for criticism and discussion. The authors would also like to thank Renee Russell and Emily Nienhuis of Pacific Northwest National Laboratory and Richard Wyrwas of Savannah River National Laboratory for their help in technical review of this article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 This material was called Carborundum Monofrax^® K-3 in some reports in the 1970s–1990s. The Carborundum Company in Falconer, NY used Monofrax as a registered trademark for the product; after years the company has changed its name to Monofrax LLC. The company has been acquired by Saint-Gobain in 2022.

Additional information

Funding

Funding for this work was supported by the U.S. Department of Energy Office of River Protection Waste Treatment & Immobilization Plant Project through Department of Energy Work Authorization M0SRV00101. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for U.S. Department of Energy by Battelle Memorial Institute operating under Contract No. DE AC05-76RL0-1830. Contributions from the Savannah River National Laboratory were produced by Battelle Savannah River Alliance, LLC under Contract No. 89303321CEM000080 with the U.S. Department of Energy. Contributions from Idaho National Laboratory were performed by Battelle Energy Alliance, LLC under DOE Idaho Operations Contract DE AC07 05ID14517.