Chemical dissolving of sludge from a high level waste tank at the Savannah River Plant

The concept for decontamination and retirement of radioactive liquid waste tanks at the Savannah River Plant (SRP) involves hydraulic slurrying to remove most of the settled sludges followed by chemical dissolving of residual sludges. Dissolving tests were carried out with small samples of sludge from SRP Tank 16H. Over 95 percent of the sludge was dissolved by 8 wt percent oxalic acid at 85/sup 0/C with agitation in a two-step dissolving process (50 hours per step) and an initial reagent-to-sludge volume of 20. Oxalic acid does not attack the waste tank material of construction, appears to be compatible with the existing waste farm processes and equipment after neutralization, and with future processes planned for fixation of the waste into a high-integrity solid for packaging and shipping