Batch test equilibration studies examining the removal of Cs, Sr, and Tc from supernatants from ORNL underground storage tanks by selected ion exchangers

摘要

Bench-scale batch equilibration tests have been conducted with supernatants from two underground tanks at the Melton Valley Storage Tank (MVST) Facility at Oak Ridge National Laboratory (ORNL) to determine the effectiveness of selected ion exchangers in removing cesium, strontium, and technetium. Seven sorbents were evaluated for cesium removal, nine for strontium removal, and four for technetium removal. The results indicate that granular potassium cobalt hexacyanoferrate was the most effective of the exchangers evaluated for removing cesium from the supernatants. The powdered forms of sodium titanate (NaTiO) and cystalline silicotitanate (CST) were superior in removing the strontium; however, for the sorbents of suitable particle size for column use, titanium monohydrogen phosphate (TiHP (phi)), sodium titanate/polyacrylonitrile (NaTiO-PAN), and titanium monohydrogenphosphate/ polyacrylonitrile (TiP-PAN) gave the best results and were about equally effective. Reillex(trademark) 402 was the most effective exchanger in removing the technetium; however, it was only slightly moresatisfactory than Reillex(trademark) HPQ.