A new processing option, copper‐catalyzed hydrogen peroxide oxidation of tetraphenylborate under alkaline conditions, was demonstrated in laboratory testing. Laboratory‐scale tests were conducted to evaluate the use of copper‐catalyzed hydrogen peroxide oxidation to treat simulants of the Savannah River Site tank waste. The oxidation process involves the reaction of hydrogen peroxide with a copper catalyst to form hydroxyl free radicals. With an oxidation potential of 2.8 volts, the hydroxyl free radical is a very powerful oxidant, second only to fluorine, and will react with a wide range of organic molecules. The goal is to oxidize the tetraphenylborate completely to carbon dioxide, with minimal benzene generation. Testing was completed in a lab‐scale demonstration apparatus at the Savannah River National Laboratory. Greater than 99.8% tetraphenylborate destruction was achieved in less than three weeks. Offgas benzene analysis by a gas chromatograph demonstrated low benzene generation. Analysis of the resulting slurry demonstrated >82.3% organic carbon destruction. The only carbon compounds detected were formate, oxalate, benzene (vapor), carbonate, p‐terphenyl, quaterphenyl, phenol, and phenol 3‐dimethylamino.