EMPIRICAL RATE EQUATION MODEL & RATE CALCULATIONS OF HYDROGEN GENERATION FOR HANFORD TANK WASTE

Measurement of Hydrogen Generation Rates during Digestion, Neutralization, Transfer, and Storage of Reillex HPQ Resin

“…The 100 °C Tank 32 control experiment exhibited an HGR of 5.5×10 -7 ft 3 H2 hr -1 gal -1 , measurably higher than that observed in the 100 °C Tank 39 control experiment (6.6×10 -8 ft 3 H2 hr -1 gal -1 ). This is consistent with the prediction offered by the Hu thermolytic HGR expression 4 that the increased aluminum loading of Tank 32 would yield a higher HGR than that of Tank 39. The HGR observed from Tank 32 simulant at 100 °C in the presence of digestion product was 3.6×10 -6 ft 3 H2 hr -1 gal -1 .…”

“…• Results from testing with Reillex ® HPQ digestion product in Tank 32 simulant at temperatures at or below 100 °C can be described by the following expression (this expression is expected to be representative of the highest hydrogen producing tanks in the CSTF and is expected to bound CSTF operations given the dependence on aluminum concentrations reported in literature [2][3][4] ).…”

“…The composition of Tank 32 includes elevated aluminum, hydroxide, and nitrate concentrations. Prior literature [2][3][4] and work in progress implicate these species as promoting higher HGRs from thermolysis. Hence, Tank 32 represents conservative waste conditions to assess hydrogen generation contribution from the discharged Reillex ® digestion products.…”

Evaluation of the Current State of Knowledge for Thermolysis of Organics within SRS Waste Forming Volatile Organic Compounds (VOCs)

“…3 Development of the HGR strategy for Hanford Site Tank Farm included testing of many simulant and actual radioactive samples. 31 Mass spectrometry was the main gas analysis technique used in these studies. Table 2-3 and Table 2-4 show summary molar gas generation rates for several radioactive tank samples as well as for a simulant of Tank AN-107 waste.…”

“…However, regardless of the TOC levels in the Hanford Site high-level waste thermolysis studies cited in this section, the methane to hydrogen ratios appear to be persistent across the range of TOC present. As a result of the tests documented above pertaining to Hanford Site high-level waste radioactive and simulant samples and others documented by Hu, 31 the current Hanford Site Tank Farm strategy for HGR assumes that methane generation is 10% of the HGR model-calculated hydrogen generation rate from radiolysis, thermolysis and corrosion. 36 As discussed in Section 4 of the Flammable Gas Generation Mechanisms report, 3 Stock reviewed the occurrence and chemistry of organic compounds in Hanford Site high-level waste tanks.…”