SUPERLIG® 639 EQUILIBRIUM SORPTION DATA FOR TECHNETIUM FROM HANFORD TANK WASTE SUPERNATES

Abstract

SuperLig® 639 ion exchange resin is currently being evaluated for technetium (⁹⁹Tc) removal from radioactive Hanford tank wastes. To assess the performance of the resin in column configuration, a multiple batch contact method was used to determine the equilibrium distribution coefficients (K_d values) and percent removal for technetium (as pertechnetate, TcO₄ ⁻) from highly alkaline waste solutions obtained from the Hanford Site. The K_d values for Hanford tank wastes AN-103, AZ-102, and AN-102 were 530, 886, and 287 mL/g, respectively. The TcO₄ ⁻K_d values for the AN-102 mixed with AN-103 after 4 hours and 14 days were 456 and 392 mL/g, respectively. The percent removal of technetium as TcO₄ ⁻anion from three Hanford tank solutions (AN-103, AZ-102, and AN-102) was higher than 80%, which is required for Hanford waste pretreatment flowsheet. The results indicate that SuperLig® 639 resin is highly selective for pertechnetate in the presence of relatively high concentrations of nitrate anion.

ACKNOWLEDGMENT

This work was conducted at the Savannah River Technology Center in Aiken, SC, which is operated for the U.S. Department of energy by Westinghouse Savannah River Company under contract DE-AC09-96SR18500. The Hanford River Protection Project Office supported this work. We are very grateful to Karen N. Palmer, Yvonne J. Simpkins, Francis Wakefield, and Myra Bussey for their assistance in the completion of the experimental work. We also thank Major Thompson for his contributions toward the experimental design and review of this work.