Abstract Radon ( 222 Rn) is a natural radioactive gas that occurs in rocks and soils and can only be detected with special equipment. Radon is a major cause of lung cancer. Therefore, early detection is essential. The British Geological Survey and Public Health England have produced a series of maps showing radon affected areas based on underlying geology and indoor radon measurements, which help to identify radon-affected buildings. Many factors influence how much radon accumulates in buildings. Remedial work can be undertaken to reduce its passage into homes and workplaces and new buildings can be built with radon preventative measures.

Abstract This paper identifies potential sources, and the key chemical properties, of methane. Guidance is provided on deriving a conceptual site model for methane, utilizing various lines of evidence to inform a robust, scientific, reasoned and logical assessment of associated gas risk. Discussion is provided regarding the legislative context of permanent gas risk assessment for methane, including via qualitative, semi-quantitative and detailed quantitative (including finite element modelling) techniques. Strategies for mitigating risks associated with methane are also outlined, together with the legal context for consideration of methane both in relation to the planning regime and under Part 2A of the Environmental Protection Act 1990.

Abstract In a deep geological repository (DGR) for the long-term containment of radioactive waste, gases could be generated through a number of processes. If gas production exceeds the containment capacity of the engineered barriers or host rock, these gases could migrate through these barriers and potentially expose people and the environment to radioactivity. Expansive soils, such as bentonite-based materials, are currently the preferred choice of seal materials. Understanding the long-term performance of these seals as barriers against gas migration is an important component in the design and long-term safety assessment of a DGR. This study proposes a hydro-mechanical linear poro-elastic visco-capillary mathematical model for advective-diffusive controlled two-phase flow through a low-permeability expansive soil. It is based on the theoretical framework of poromechanics, incorporates Darcy’s Law for both the porewater and poregas, and a modified Bishop’s effective stress principle. Using the finite element method (FEM), the model was used to numerically simulate 1D flow through a low-permeability expansive soil. The results were verified against experimental results found in the current literature. Parametric studies were performed to determine the influence on the flow behaviour. Based on the results, the mathematical model looks promising and will be improved to model flow through preferential pathways.

Abstract In 2014, the Geological Survey of Austria (GBA) published – in cooperation with further national institutions – an overview map on radionuclides in groundwater, rocks and stream sediments at a scale of 1:500 000 with explanatory notes. In the frame of this activity, the uranium, 228 Ra, 226 Ra, 222 Rn, 210 Pb and 210 Po analyses in groundwater studies made by the Austrian Agency for Health and Food Safety (AGES) and Environment Agency of Austria (Umweltbundesamt), as well as the uranium and thorium analyses of stream sediments of the GBA and whole-rock analyses from different sources, were evaluated statistically. Furthermore, the GBA’s comprehensive airborne radiometric data were exploited. The aim of this study was to work out typical spectra of the radionuclide content in the groundwater and aquifers of different geological settings. It appeared that the concentration of 222 Rn in groundwater depends significantly on the uranium content of the aquifer. In contrast to this, the other radionuclides in groundwater did not show a clear correlation with uranium and thorium in the subsurface geology. Concerning 228 Ra, 226 Ra, 210 Pb and 210 Po, the lack of relationship to the subsurface composition seems to be a result of the low concentrations in groundwater. With respect to uranium in groundwater, there is a mixed situation: on the one hand, high uranium concentrations in groundwater can be observed in the Alps in regions with uranium bearing orthogneisses. On the other hand, in sediment basins of NE Austria where the underlying geology contains little uranium. Whether this is caused by special geological features combined with the given low precipitation or by the extensive agriculture (uranium from phosphate fertilizer) is under examination. Concerning the threshold values of the radionuclides in groundwater (radiation), no exceedance could be observed. In spite of this, the concentration of the heavy metal uranium sometimes exceeded the threshold value of 15 µg l −1 : this is especially true for the regions mentioned above. In addition, an attempt was made to compare the Austrian values with data from neighbouring countries. It became clear that only a few published datasets exist that are comparable. Radon analyses of soil gas in the Czech Republic and Bavaria show the same geological patterns as the Austrian radon analyses of the groundwater. In addition, to enable the reader to compare the Austrian data with datasets from other countries, additional tables are included here for all types of data. They show the statistic distributions of different geological classes in a coordinated way. Supplementary material: An Austrian map and explanation notes showing the uranium content of the underground and radionuclides in ground water are available at https://doi.org/10.6084/m9.figshare.c.3780170