(238c) Glycolic Acid Flowsheet Development For The Defense Waste Processing Facility

The Defense Waste Processing Facility (DWPF) processes legacy nuclear waste generated at the Savannah River Site (SRS) during production of plutonium and tritium demanded by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass canisters is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides.

Testing has demonstrated that the replacement of formic acid with glycolic acid in the DWPF’s chemical processing flowsheet essentially eliminated catalytic hydrogen generation.  Hydrogen is generated in chemical processing of alkaline High Level Waste sludge in DWPF.  In current processing, sludge is combined with nitric and formic acid to neutralize the waste, reduce mercury and manganese, destroy nitrite, and modify (thin) the slurry rheology.  The noble metal catalyzed formic acid decomposition produces hydrogen and carbon dioxide. 

Final testing has been completed before implrmentaition of the new flowsheet in the DWPF.  Successful testing to demonstrate melter performance, prediction of glass REDOX from analytical results, scaleup of the process from lab scale to 1:216 scale, and an actual waste demonstration were completed.  The results from this testing will discussed.