STRONTIUM AND ACTINIDE SORPTION BY MST AND MMST UNDER CONDITIONS REVELANT TO THE SMALL COLUMN ION-EXCHANGE PROCESS

Taylor-Pashow, K. ; Hobbs, D. ; Poirier, M.

Savannah River Site (S.C.)

关键词: Desorption;    Removal;    Radioactive Waste Processing;    Testing;    Actinides;   

DOI  :  10.2172/1013350
RP-ID  :  SRNL-STI-2011-00215
RP-ID  :  DE-AC09-08SR22470
RP-ID  :  1013350

美国|英语

来源: UNT Digital Library

【 摘 要 】

A series of tests were performed to examine the kinetics of Sr and actinide removal by monosodium titanate (MST) and modified monosodium titanate (mMST) under mixing conditions similar to what will be provided in the Small Column Ion Exchange (SCIX) Program. Similar removal kinetics were seen for two different mixing energies, indicating that under these conditions bulk solution transport is not the rate limiting step for Sr and actinide removal. Sr removal was found to be rapid for both MST and mMST, reaching steady-state conditions within six hours. In contrast, at least six weeks is necessary to reach steady-state conditions for Pu with MST. For mMST, steady-state conditions for Pu were achieved within two weeks. The actual contact time required for the SCIX process will depend on starting sorbate concentrations as well as the requirements for the decontaminated salt solution. During testing leaks occurred in both the MST and mMST tests and evidence of potential desorption was observed. The desorption likely occurred as a result of the change in solids to liquid phase ratio that occurred due to the loss of solution. Based on these results, Savannah River National Laboratory (SRNL) recommended additional testing to further study the effect of changing phase ratios on desorption. This testing is currently in progress and results will be documented in a separate report.