Advanced High-Level Waste Glass Research and Development Plan

Abstract

Executive SummaryThe U.S. Department of Energy Office of River Protection (ORP) has implemented an integrated program to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product quality requirements. The integrated ORP program is focused on providing a technical, science-based foundation from which key decisions can be made regarding the successful operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) facilities. The fundamental data stemming from this program will support development of advanced glass formulations, key process control models, and tactical processing strategies to ensure safe and successful operations for both the low-activity waste (LAW) and high-level waste (HLW) vitrification facilities with an appreciation toward reducing overall mission life.

A crucible salt saturation method for determining sulfur solubility in glass melt

“…The Hanford Waste Treatment and Immobilization Plant (WTP) is under construction, aiming to separate the wastes into high‐volume low‐activity waste (LAW) and low‐volume high‐level waste (HLW) fractions and vitrify the wastes into separate glass waste forms . Many efforts have been devoted to maximizing the waste loading in glass, which can minimize the waste glass volume and reduce mission cost …”

“…The LAW, a processed water solution containing soluble salts from the tank waste, consists of Na + (predominant cation), (predominant anion), K + , , , , , F − , Cl − , and other minor constituents including organics . Sulfate is one of the critical constituents that limit waste loading for many LAW glasses . The term “sulfur melter tolerance” is defined as the maximum concentration of SO 3 in melter feed (when expressed in terms of oxides and halogens) that does not form a measurable salt layer under nominal operating conditions of the Hanford LAW melter.…”

“…This salt segregation and accumulation can cause processing problems, such as corrosion of refractory materials, metallic components, and facilitate volatility of hazardous components such as 99 Tc during melting . In early waste glass formulation work, the sulfur limit was set conservatively at 0.44 wt% to 1 wt% SO 3 in order to avoid potential salt accumulation …”

Product Consistency Test Results for the High-Chromium Matrix Glasses

“…The glasses were selected as part of a broader study of the influence of glass composition on chemical durability, sulfur retention, and other properties. 2,3 The glasses were designated the DHW19M-series glasses. The resulting data will be used in the development of improved property/composition models for nuclear waste glasses.…”

Recognition and Extraction of Cesium Hydroxide and Carbonate by Using a Neutral Multitopic Ion‐Pair Receptor

“…In the US alone there are roughly 90 million gallons of legacy tank waste. [1] Much of this is highly basic (pH>13; [OH − ] = 0.02 – 8.1 M; [CO 3 2− ] = 0.005 – 1.4 M). [2] Finding ways to lower the pH of this waste by removing the basic anions (e.g., OH − and CO 3 2− ), rather than adding a Brønsted acid, could prove advantageous.…”