Low temperature hydrothermal processing of organic contaminants in Hanford tank waste

Conference · Mon Feb 01 04:00:00 EST 1993

OSTI ID:10142779

Jones, E O; Pederson, L R; Freeman, H D; Schmidt, A J ^[1]; Babad, H ^[2]

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1. Pacific Northwest Lab., Richland, WA (United States)
2. Westinghouse Hanford Co., Richland, WA (United States)

Batch and continuous flow reactor tests at Pacific Northwest Laboratory (PNL) have shown that organics similar to those present in the single-shell and double-shell underground storage tanks at Hanford can be decomposed in the liquid phase at relatively mild temperatures of 150{degree}C to 350{degree}C in an aqueous process known as hydrothermal processing (HTP). The organics will react with the abundant oxidants such s nitrite already present in the Hanford tank waste to form hydrogen, carbon dioxide, methane, and ammonia. No air or oxygen needs to be added to the system. Ferrocyanides and free cyanide will hydrolyze at similar temperatures to produce formate and ammonia and may also react with nitrates or other oxides. During testing, the organic carbon was transformed first to oxalate at{approximately}310{degree}C and completely oxidized to carbonate at {approximately}350{degree}C accompanied by hydroxide consumption. Solids were formed at higher temperatures, causing a small-diameter outlet tube to plug. The propensity for plugging was reduced by diluting the feed with concentrated hydroxide.

• Research Organization: Pacific Northwest Lab., Richland, WA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 10142779
• Report Number(s): PNL-SA--21893; CONF-930205--46; ON: DE93009815
• Country of Publication: United States
• Language: English

Related Subjects

052001
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
AMMONIA
CARBON DIOXIDE
CARBONATES
CHEMICAL ANALYSIS
CORROSION
FERROCYANIDES
FLAMMABILITY
HANFORD RESERVATION
HYDROGEN
METHANE
NITRITES
ORGANIC COMPOUNDS
OXALATES
OXIDATION
OXIDIZERS
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTES
SAFETY
SIMULATION
STAINLESS STEEL-304L
STOICHIOMETRY
TANKS
WASTE PROCESSING