Amphos 21 (Spain)

Radioactive waste geological disposal is considered as a feasible and safe solution, but requires detailed understanding of the interactions between the radionuclides and the components of the disposal system. A key process limiting the mobility of radionuclides is sorption, which determines how these elements interact with solid phases such as clay and cement within geological and engineered barriers. Effective management of sorption data is required to improve traceability and confidence in safety analyses and to demonstrate the long-term safety of the repository. Sorption is classically determined by means of sorption experiments (e.g. isotherms, edges) and related thermodynamic sorption modelling. Extensive knowledge is already available in the scientific literature for the sorption of many radionuclides and toxic contaminants onto relevant solid phases. Sorption is known to be system specific and strongly dependent on the chemical conditions (e.g. ligand concentrations, redox conditions, pH). Sorption databases provide a sound framework for recording all relevant information and are expected to provide a robust basis for making good use of the knowledge in the safety case. This paper presents the development and current status of a sorption database system tailored to the specific needs of the Belgian programme, in particular disposal in poorly indurated clays (i.e. Boom Clay and Ypresian clays).

Peer reviewed

A sealed container for the geological disposal of spent nuclear fuel and vitrified high-level waste is the only component of a deep geological repository that provides complete containment of radionuclides. As such, attention is focused on its lifetime. The lifetime of the container is influenced by material degradation processes during disposal and is typically of the order of several millennia and, for some container materials, up to one million years. Designing, manufacturing, and predicting the performance of containers over such long periods requires an in-depth understanding of their material properties, fabrication processes, and degradation mechanisms. Scientific and technological progress can improve both the performance of containers and the robustness of lifetime predictions. Optimization of these aspects is of primary importance for many national radioactive waste disposal programs. In this article, the state of the art of complex coupled degradation processes, as well as the optimization potential of novel container materials, is presented. Furthermore, the existing tools allowing the prediction of long-term barrier integrity are discussed.

In Hydrogeology, numerical models are presented as essential tools for integrating, understanding, and predicting groundwater processes. However, these models face significant challenges: on the one hand, boundary conditions and hydraulic parameters are often subject to a large degree of uncertainty, and, on the other hand, numerical models usually require advanced solving and calibration techniques that generally imply long runtimes. Recently, innovative machine learning models have emerged as a promising alternative to address these issues and thus, the application of artificial intelligence in hydrology has increased significantly. In this study we present a hybrid model designed to predict groundwater heads in response to pumping. This model generates an initial analytical approximation of groundwater heads which is later enhanced by a machine learning framework based on recurrent neural networks. A real application of a pumping field for urban supply in Spain is presented as an illustration of the practical application of the presented methodology. Following model training and validation, we have also integrated a genetic algorithm to optimise flow rates, aiming to minimise energy consumption and/or head drawdowns. The results reveal that our hybrid approach achieves highly accurate head predictions with normalised absolute mean error lower than 4% which implies that the model reproduces properly the head measurements. Additionally, the optimisation algorithm successfully reduces energy consumption by 25%. This methodology represents a groundbreaking approach to quantify the effects of intense pumping and to facilitate long-term management of groundwater resources.

Abstract Climate change is generating range shifts in many organisms, notably along the altitudinal gradient. However, moving up in altitude exposes organisms to lower oxygen availability, which may negatively affect development and fitness, especially at high temperatures. To test this possibility in a potentially upward-colonizing species, we artificially incubated developing embryos of the viperine snake Natrix maura Linnaeus 1758, using a split-clutch design, in conditions of extreme high elevation or low elevation at two ecologically-relevant incubation temperatures (24 and 32 °C). Embryos at low and extreme high elevations incubated at cool temperatures did not differ in development time, hatchling phenotype or locomotor performance. However, at the warmer incubation temperature and at extreme high elevation, hatching success was reduced. Further, embryonic heart rates were lower, incubation duration longer and juveniles born smaller. Nonetheless, snakes in this treatment were faster swimmers than siblings in other treatment groups, suggesting a developmental trade-off between size and performance. Constraints on development may be offset by the maintenance of important performance metrics, thus suggesting that early life-history stages will not prevent the successful colonization of high-elevation habitat even under the dual limitations of reduced oxygen and increased temperature.

Earth and Space Science Open Archive posterOpen AccessYou are viewing the latest version by default [v1]SKB Task Force GWFTS: Task 9 - Increasing the realism of solute transport modelling in fractured mediaAuthorsBjörnGyllingiDPaoloTrincheroiDJosepSoleriDJamesCrawfordKerstiNilssoniDBillLanyonJan-OlofSelroosiDAnttiPoteriSee all authors Björn GyllingiDCorresponding Author• Submitting AuthorGylling GeoSolutionsiDhttps://orcid.org/0000-0002-2464-6725view email addressThe email was not providedcopy email addressPaolo TrincheroiDAmphos21iDhttps://orcid.org/0000-0003-1351-2788view email addressThe email was not providedcopy email addressJosep SoleriDIDAEA-CSICiDhttps://orcid.org/0000-0003-0741-249Xview email addressThe email was not providedcopy email addressJames CrawfordKemakta Konsult ABview email addressThe email was not providedcopy email addressKersti NilssoniDGeosigma ABiDhttps://orcid.org/0000-0001-7140-5863view email addressThe email was not providedcopy email addressBill LanyonFracture Systems Ltd.view email addressThe email was not providedcopy email addressJan-Olof SelroosiDSKB (Svensk Kärnbränslehantering AB)iDhttps://orcid.org/0000-0001-9251-5367view email addressThe email was not providedcopy email addressAntti PoteriPosiva Oyview email addressThe email was not providedcopy email address