(477d) Chemical Reaction Networks in High Level Waste (HLW) Treatment at the Defense Waste Processing Facility (DWPF)

vitrification of high‐level radioactive waste contained in 50+ tanks at the Savannah River Site (SRS) in

Aiken, S.C. Recently, scientists and engineers at Savannah River National Laboratory (SRNL) have

proposed the replacement of formic acid (currently used to chemically treat radioactive waste) with

glycolic acid, citing similar chemical behavior and diminished generation of flammable hydrogen. In an

effort to further understand the interactions of glycolic acid with nuclear waste, several single component

reactions have been investigated to determine critical processing parameters such as

required acid loading as a function of waste composition. Additionally, multi‐component reactions have

been studied in order to observe any synergistic or interfering interactions. Results demonstrating the

complicated network of nitrogen‐oxide reactions present in the DWPF Chemical Process Cell (CPC) will

be presented, as will the synergistic effects of nitrite concentration on manganese reductive dissolution.

A particular focus will be given to NOx generation‐conversion‐scrubbing cycles observed during testing.

In addition, the observed effects of waste composition on glycolic acid fate will be discussed, particularly

the generation of formic acid, oxalic acid, and carbon dioxide from oxidized glycolic acid. Potential

impacts of these findings on processing at the DWPF will also be discussed. Data presented will include

analyses by mass spectrometry (MS), Fourier‐transform infrared spectroscopy (FT‐IR), ion

chromatography (IC), and inductively‐coupled plasma‐atomic emission spectroscopy (ICP‐AES).