Waste and Simulant Precipitation Issues

Steele, W.V.

Oak Ridge National Laboratory

关键词: Leaching;    Testing;    Decontamination;    Personnel;    Simulation;   

DOI  :  10.2172/814055
RP-ID  :  ORNL/TM-2000/348
RP-ID  :  AC05-00OR22725
RP-ID  :  814055

美国|英语

来源: UNT Digital Library

【 摘 要 】

As Savannah River Site (SRS) personnel have studied methods of preparing high-level waste for vitrification in the Defense Waste Processing Facility (DWPF), questions have arisen with regard to the formation of insoluble waste precipitates at inopportune times. One option for decontamination of the SRS waste streams employs the use of an engineered form of crystalline silicotitanate (CST). Testing of the process during FY 1999 identified problems associated with the formation of precipitates during cesium sorption tests using CST. These precipitates may, under some circumstances, obstruct the pores of the CST particles and, hence, interfere with the sorption process. In addition, earlier results from the DWPF recycle stream compatibility testing have shown that leaching occurs from the CST when it is stored at 80 C in a high-pH environment. Evidence was established that some level of components of the CST, such as silica, was leached from the CST. This report describes the results of equilibrium modeling and precipitation studies associated with the overall stability of the waste streams, CST component leaching, and the presence of minor components in the waste streams.