Waste Loading in Hanford: DOE vs. GSI-2000 PerformanceA. Chekhmir & A. Gribetz
The DOE Hanford site near Richland, Washington, stores more than 200 million liters of radioactive waste. This waste will be pre-treated at a Waste Treatment Plant, and subsequently separated into HLW (<10% of waste mass) and LAW (> 90% of waste mass).
Hanford HLW Waste Loadings: DOE vs. GSI-2000
DOE estimates that it will produce between 10,000 and 14,000 HLW canisters in Hanford over a 23- to 35-year period, depending upon the effectiveness of its initiatives to increase waste loading in the glass. The current DOE benchmark performance is approximately 26 wt% average waste loading which would result in production of 14,000 canisters. DOE considers a 31 wt% average waste loading (which would produce 12,700 canisters) to be a plausibly attainable increase in waste loading. To be conservative, we compare the performance of GSI-2000 to the 31 wt% waste loading. Hanford HLW is divided into 89 “batches” which are combined into 17 compositional groups (“clusters”) with similar chemical constituents. GSI chose a representative batch from 10 clusters* (representing 91% of Hanford HLW) and formulated glasses with high waste loadings. Table 3 below presents the waste loadings achieved by GSI at laboratory-scale. GSI-2000 has reached a weighted average waste loading of 46.3 wt% compared to DOE’s projected 31 wt% waste loading.
* Waste compositions taken from Tanks Focus Area HLW Melter Study Report (July 2001), Appendices C and E
Hanford LAW Waste Loadings: DOE vs. GSI-2000Assuming all of the LAW at Hanford is vitrified DOE would produce approximately 47,000 canisters of LAW glass at a projected average 19 wt% sodium loading. Of note, the possibility exists that up to 50% of the LAW may be treated by Bulk Vitrification, a supplemental treatment, for which GSI-2000 is also applicable.
Applying GSI-2000 to two Hanford LAW simulants (one based on the high-sodium, high-sulfate 222-S Saltcake Composite simulant representative of the majority of the LAW to be treated by vitrification, and one based on the high-sodium Tank 241-S-109 simulant representative of the LAW to be treated possibly by Bulk Vitrification,* GSI achieved sodium loadings of 27.7 wt% and 30 wt%, respectively.
*Simulants taken from Pacific Northwest National Laboratory - 14194, Cold Dissolved Saltcake Waste Simulant Development, Preparation, and Analysis (February 2003), and Pacific Northwest National Laboratory - 15699, Tank 241-S-109 Saltcake Simulant Development and Testing (March 2006)