Vitrification of ion exchange materials. Innovative technology summary report
Ion exchange is a process that safely and efficiently removes radionuclides from tank waste. Cesium and strontium account for a large portion of the radioactivity in waste streams from US Department of Energy (DOE) weapons production. Crystalline silicotitanate (CST) is an inorganic sorbent that strongly binds cesium, strontium, and several other radionuclides. Developed jointly by Sandia National Laboratory and Texas A and M University, CST was commercialized through a cooperative research and development agreement with an industrial partner. Both an engineered (mesh pellets) and powdered forms are commercially available. Cesium removal is a baseline in HLW treatment processing. CST is very effective at removing cesium from HLW streams and is being considered for adoption at several sites. However, CST is nonregenerable, and it presents a significant secondary waste problem. Treatment options include vitrification of the CST, vitrification of the CST coupled with HLW, direct disposal, and low-temperature processes such as grouting. The work presented in this report demonstrates that it is effective to immobilize CST using a baseline technology such as vitrification. Vitrification produces a durable waste form. CST vitrification was not demonstrated before 1996. In FY97, acceptable glass formulations were developed using cesium-loaded CST obtained from treating supernatants from Oak Ridge Reservation (ORR) tanks, and the CST was vitrified in a research melter at the Savannah River Technology Center (SRTC). In FY98, SRS decided to reevaluate the use of in-tank precipitation using tetraphenylborate to remove cesium from tank supernatant and to consider other options for cesium removal, including CST. Hanford and Idaho National Engineering and Environmental Laboratory also require radionuclide removal in their baseline flowsheets.
- Research Organization:
- Dept. of Energy, Office of Science and Technology, Washington, DC (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
- OSTI ID:
- 10143908
- Report Number(s):
- DOE/EM-0451; ON: DE99002933; IN: OST Reference No. 81; NC: NONE; TRN: AHC29927%%5
- Resource Relation:
- Other Information: PBD: Jul 1999
- Country of Publication:
- United States
- Language:
- English
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