engleski

Numerical models of the deep geological repository for the spent nuclear fuel

Numerical analysis of the deep geological repository (DGR) for the spent nuclear fuel (SNF) and/or high-level radioactive waste (HLW) is crucial part of safety case for every SNF/HLW disposal program. Before any activity concerning the disposal starts it is necessary to prove functionality of the future disposal concept applied to the specific host rock. Apart from laboratory work, including underground research laboratories (URLs), which should also prove applicability of the disposal concept and appropriateness of the host rock and buffer material, numerical model of the future DGR should be designed and tested in order to check the adequacy of the solution, to identify possible errors and problems, and to adjust future works, the dimensions of individual elements of the repository and the choice of materials. Numerical models presented in this paper are developed for the KBS-3V concept for the disposal of the SNF and/or HLW, in Plaxis and GeoStudio software. Granodiorite was selected as a host rock, and sodium bentonite as buffer material. Comparison of respected models created in these two software packages, as well as their verification according to required safety parameters for the repository, are discussed and compared to state-of-the-art research of running programs (i.e., Finnish and Swedish SNF disposal program). Outcomes of the research show that both software give alike results, comparable and with an equal stress distribution with respect to the shape of the underground spaces. Both numerical models show that the excavated spaces will remain stable even without the support system, and that maximal displacement will not affect the disposal tunnel and borehole. It is evident that the presented numerical models correspond to the results of other similar research and that they may possibly be used for the development of safety case and testing the design of future repository of SNF or HLW.

: numerical model ; deep geological repository ; spent nuclear fuel ; bentonite ; granodiorite

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