Evaluation of mercury in liquid waste processing facilities - Phase I report

Assessment of Methane Generation from the Thermolysis of Organics in Caustic Waste

“…With over 60 MT of mercury in SRS tanks, one would anticipate methylmercury concentrations to continually increase over time. 25 Simulant waste studies at three temperatures (39 °C, 65 °C, and 83 °C) found that in the presence of organics, Hg(II) is rapidly methylated to methylmercury; however, a rate for the methylation could not be determined due to the nature of the study. 26,27 In comparison, the rate of formation for dimethylmercury is relatively slow, but increases with increasing temperature.…”

Separation and Speciation of Mercury from Hanford 241-AP-107 Tank Waste Supernatant

“…In 2014, the SRS observed high levels of mercury in a TCLP as part of normal monitoring of the lowlevel cementitious waste form produced at SWPF (Jain et al 2015;Bannochie et al 2017). The TCLP value was higher than the LDR treatment standard for mercury of 0.025 mg/L.…”

“…Moreover, the dominant form of mercury that was released was methylmercury, the highly toxic mercury form due to its ability to bioconcentrate in biological tissues and magnify up the food chain (Weiner et al 2002). This unexpected discovery prompted investigations into the speciation of mercury in the liquid waste stream (Jain et al 2015). It was subsequently discovered that there were elevated levels of methylmercury in the decontaminated salt feed to the low-level waste operations.…”

Phase 2 Report--Mercury Behavior In The Defense Waste Processing Facility

“…Based on the objectives listed above, a two phased approach was taken. The first phase was dedicated to a review of the liquid waste inventory and chemical processing behavior using a system by system review methodology approach 2 . The methodology included assessing current knowledge, identification of gaps/information needs, and identification and execution of selected near term action recommendations.…”