Helium behaviour in waste conditioning matrices during thermal annealing
| Autor: | R. Fromknecht, P.M.G. Damen, J.-P. Hiernaut, William J. Weber, S. Lutique, Thierry Wiss |
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| Rok vydání: | 2006 |
| Předmět: |
Nuclear and High Energy Physics
Nuclear fission product Fission products Zirconolite Materials science Metallurgy Radiochemistry chemistry.chemical_element Radioactive waste respiratory system Spent nuclear fuel High-level waste Nuclear Energy and Engineering chemistry General Materials Science Energy source Helium |
| Zdroj: | Journal of Nuclear Materials. 352:202-208 |
| ISSN: | 0022-3115 |
| Popis: | Reprocessing of spent fuel produces high level waste including minor actinides and long living fission products that might be disposed in waste conditioning matrices. Several natural mineral phases were proven to be able to incorporate fission products or actinides in their crystalline structure for long periods of time. In this study, synthetic compounds of zirconolite (CaZrTi2O7) and pyrochlores (Gd2Ti2O7 and Nd2Zr2O7) were fabricated and doped with the short-lived alpha-emitter 244Cm to increase the total amount of helium and damage generated in a laboratory time scale. Helium implantations were also used to simulate the damage caused by the alpha-decay and the build-up of helium in the matrix. The samples were annealed in a Knudsen cell, and the helium release profile interpreted in conjunction with radiation damage studies and previous analysis of annealing behaviour. Several processes like diffusion, trapping or phase changes could then be attributed to the helium behaviour depending on the material considered. Despite high damage and large amount of helium accumulated, the integrity of the studied materials was preserved during storage. |
| Databáze: | OpenAIRE |
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