Investigation of Thermolytic Hydrogen Generation Rate in Tank 28 and Tank 39 Samples

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

“…Revision 0 vii [1][2][3][4] Methane was also detected in further thermolytic HGR testing, specifically with simulants containing trimethylsilanol (TMS). 1,5 This evidence of thermolytic methane generation prompted the authoring of the report, Evaluation of the Current State of Knowledge for Thermolysis of Organics within SRS Waste Forming Volatile Organic Compounds (VOCs).…”

“…In HGR radioactive waste testing, methane was detected in samples at elevated temperatures for Tanks 28, 38, and 44. [1][2][3][4] Volatile organic analysis (VOA) of the Tank 44 samples found 0.9 mg/L of octamethylcyclotetrasiloxane. 4 Octamethylcyclotetrasiloxane is possibly a degradation product or impurity of antifoam H-10, a polydimethylsiloxane-based antifoam that was formerly used in Concentration, Storage and Transfer Facility (CSTF) evaporators.…”

“…23 Dimethylmercury concentrations are typically below 1 mg/L, while methylmercury (MeHg + ) concentrations have been found up to 200 mg/L. 3 It is suspected that CH 3 HgOH is the predominate form of methylmercury in caustic tank waste. 24 The large concentrations of methylmercury found in tank waste is primarily due to its solubility and low vapor pressure.…”

Evaluation of Thermolytic Production of Hydrogen from Glycolate and Common Tank Farm Organics in Simulated Waste

“…23 Six tanks were identified for SRNL to perform HGR testing without and with added glycolate: 22, 28, 38, 39, 44, and 50. [24][25][26][27] To date, results from five of the six tests have been published in SRNL technical reports. No appreciable impact from added glycolate was observed in Tank 22 material.…”

Evaluation of Thermolytic Hydrogen Generation Rate Models at High-Temperature/High-Hydroxide Regimes

“…[4][5] To date, SRNL personnel have performed several series of tests on both radioactive and simulated caustic waste to measure the thermolytic production of hydrogen gas from organics, including glycolate. [6][7][8][9] These hydrogen generation rate (HGR) measurements performed by SRNL have led to the generation of model expressions for the thermolytic production of hydrogen from glycolate and non-glycolate organics in caustic waste. 9 The HGR expression for glycolate thermolysis is derived from simulant testing and confirmed with radioactive waste testing with added glycolate.…”