Title: | Stabilization/Solidification of radioactive molten salt waste via gel-route pretreatment |
Author(s): | Park HS; Kim IT; Kim HY; Ryu SK; Kim JH; |
Address: | "Nuclear Fuel Cycle R&D Group, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon, 305-353, Korea. hspark72@kaeri.re.kr" |
ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
Abstract: | "The volatilization of radionuclides during the stabilization/solidification of radioactive wastes at high temperatures is one of the major problems to be considered in choosing suitable wasteforms, process, material systems, etc. This paper reports a novel method to convert volatile wastes into nonvolatile compounds via a sol-gel process, which is different from the conventional method using metal-alkoxides and organic solvents. The material system was designed with sodium silicate (Si) as a gelling agent, phosphoric acid (P) as a catalyst/stabilizer, aluminum nitrate (Al) as a property promoter, and H20 as a solvent. A novel structural model for the chemical conversion of molten salt waste, named RPRM (Reaction Product in Reaction Module), was established, and the waste could be solidified with glass matrix via a simple procedure. The leached fraction of Cs and Sr by a PCT leaching method was 0.72% and 0.014%, respectively. In conclusion, the RPRM model isto converttargetwastes into stable and manageable products, not to obtain a specific crystalline product for each radionuclide. This paper suggested a new stabilization/solidification method for salt wastes by establishing the gel-forming material system and showing a practical example, not a new synthesis method of stable crystalline phase. This process, named 'gel-route stabilization/solidification (GRSS)', will be a prospective alternative with stable chemical process on the immobilization of salt wastes and various mixed radioactive waste for final disposal" |
Keywords: | Aluminum Compounds/chemistry Chlorides/chemistry Gels Nitrates/chemistry Phosphoric Acids/chemistry *Radioactive Waste Refuse Disposal/*methods Silicates/chemistry; |
Notes: | "MedlinePark, Hwan-Seo Kim, In-Tae Kim, Hwan-Young Ryu, Seung-Kon Kim, Joon-Hyung eng Research Support, Non-U.S. Gov't 2007/06/28 Environ Sci Technol. 2007 Feb 15; 41(4):1345-51. doi: 10.1021/es0615472" |