Nuclear fuel waste immobilization

At the final stage, where disposal must proceed, there are two basic approaches. Firstly to contain the waste or pollutant, immobilized in a controlled manner. The pollutant is then localized and release is subject to the lifetime of the containment barriers, under the storage conditions used. This is relatively straightforward where the lifetime of the hazard is short but a major consideration in the longer term, where containment must perform adequately for many hundred and thousands of years. The management of radioactive waste from the nuclear fuel cycle is perhaps the most appropriate example here of the latter. ... 

The disposal of actinides requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., Pu and Np) are long lived, they have a major impact on risk assessments of geologic repositories [46, 47]. Current research concerns new specific matrices designed for the immobilization of these long-lived radio nuclides. 

Law, J.D., T.G. Cam, R.S. Herbst, D.H. Meikrantz, D.R. Peterman, C.L. Riddle, T.A. Todd, and J.L. Tripp. 2006. Development of cesium and strontium separation and immobilization technologies in support of an advanced nuclear fuel cycle. WM 06 Proceedings of the Waste Management... 

AHWR = Advanced Heavy Water Reactor Dep. U = Depleted Uranium Fuel Reproc. = Fuel Reprocessing HWB = Heavy Water Board IRE = Indian Rare Earth NFC = Nuclear Fuels Complex SSSF = Solid Storage and Survellance Facility UCIL = Uranium Corporation of India Limited WIP = Waste Immobilization Plant. 

The recovery of U and Pu in the closed nuclear fuel cycle usually produces an high level waste (HLW) stream containing high concentration of fission/activation products (e.g., U, Pu, Am, Eu, Sr) and process/structural materials (Fe, Ni, Cr, etc.). This concentrated HLW is typically submitted to immobilization in glass/ceramic matrices, followed by their disposal in geological repositories. Considering the half-lives of the fission products (in the range of hundred-millions years) this solution result is unsustainable. The treatment of HLW by SLM represents a possible alternative. 

VITRIFICATION. A method for the disposal of waste by immobilizing it in a type of leach-resistant glass. This method is sometimes used to dispose of waste radioactive materiais, such as spent nuclear fuel. It can also be used to dispose of soil that has been contaminated with... 

While public understanding of nuclear issues may lack sophistication and is often based on inadequate or even misleading information, the public s assessments are not irrational. Having been told over many years that spent fuel is nuclear waste, it is only natural that the public should insist on its disposal. If and when effectively informed ofthe fact that spent fuel is not a waste but an energy resource, there is every reason to believe that the public will reject its deliberate burial and favor its storage under secure conditions, just as it now favors consuming, rather than immobilizing, surplus weapons plutonium. 

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