Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

Technical Report · Wed Apr 01 04:00:00 EST 1998

DOI:https://doi.org/10.2172/651624· OSTI ID:651624

Barnes, M J ^[1]; Peterson, R A

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1. Westinghouse Savannah River Company, AIKEN, SC (United States)

The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variables on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation.

• Research Organization: Westinghouse Savannah River Company, Aiken, SC (United States); Westinghouse Savannah River Co., Aiken, SC (United States)
• Sponsoring Organization: USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
• DOE Contract Number: AC09-96SR18500
• OSTI ID: 651624
• Report Number(s): WSRC-TR--98-00099; ON: DE98053169
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
BENZENE
CATALYSTS
DECOMPOSITION
EXPERIMENTAL DATA
PALLADIUM
PRECIPITATION
REACTION KINETICS
SODIUM BORIDES
TANKS