Modeling of a radionuclide transport experiment in granitic rock matrix at the Grimsel Test Site (Switzerland). The role of advection

Within the framework of the GTS-LTD project (Grimsel Test Site – Long-Term Diffusion), a radionuclide transport experiment in unfractured granitic rock matrix was performed. Grimsel groundwater containing several radionuclide tracers (3H as HTO, 36Cl−, 22Na+, 134Cs+, 133Ba2+) was continuously circulated through a packed-off borehole interval. The decrease in tracer concentrations in the solution was monitored for a period of 1266 days (March 05, 2014–August 22, 2017). Additionally, tracer breakthrough was monitored in an observation borehole at a distance of 18.6 cm. Initial modeling of the experiment (1D radial), considering transport only by diffusion, showed that the evolution of tracer concentrations departed from the expected trend after some time, with concentrations in the injection borehole decreasing faster than expected. Additional 2D calculations (section normal to the boreholes) were performed to check the possible effect of advection through the rock matrix. Advection could explain the evolution of concentrations in the injection borehole, but concentrations in the observation borehole were overestimated. Core samples from new boreholes were collected immediately after the end of the experiment, allowing the measurement of tracer distributions in the rock. The observed patterns for the non-sorbing tracers (HTO, 36Cl−) showed clear preferential transport directions, consistent with advective flow towards the gallery from which the boreholes were drilled. Final 3D modeling of the experiment can explain the measured concentrations in the boreholes and in the rock. Tracer transport for the conservative tracers (HTO, 36Cl−) is affected by both diffusion and advection through the granitic rock matrix. Also, in situ accessible porosities deduced from the modeling (0.0014) are smaller than those measured in rock samples (about 0.009), pointing to unloading and destressing of the rock samples after drilling. At the spatial and temporal scales of the experiment, the effect of advection for the weakly sorbing 22Na+ is only minor, and it is practically negligible for the strongly sorbing tracers (134Cs+, 133Ba2+).The GTS-LTD project is financed by its partner institutions: JAEA (Japan), NUMO (Japan), UJV (Czech Rep.), SURAO (Czech Rep.), NAGRA (Switzerland) and BASE (Germany). IDAEA-CSIC is a Severo Ochoa Center of Research Excellence (Spanish Ministry of Science and Innovation, Project CEX 2018-000794-S). JMS acknowledges support from the Catalan Government through project 2021SGR00308. JJH acknowledges support from Grant RYC-2017-22300 funded by MCIN/AEI (10.13039/501100011033) and the European Social Fund “Investing in your future”. Finally, the constructive comments from two anonymous reviewers are gratefully acknowledged.Peer reviewe

Corporate assets and investment business activities

The main objective of this thesis was to assess the property structure in the selected company, focusing on amenities, the level and effectiveness of the tangible assets as a basis for evaluating investment activity and its impact on the overall management of the company

Design of a constructed wetlands for wastewater treatment at Lhota u Nahořan

The thesis deals with the constructed wetlands (an aquatic plant root filter). It characterizes a principle of effluent treatment, types of wetlands and treatment process. A part of the thesis is focused on wastewater sampling sites in Lhota u Nahořan (situated nearby Náchod in Hradec Králové region) and on process of their evaluation. It also describes the location and method of wastewater flow measurement. The collected indicators of pollution and flow rates of the brook in Lhota were used for hydro-technical calculations required for their own constructed wetland project in Lhota u Nahořan. There are two design options suggested for this given location with a population of 73 residents and where the average wastewater flow, as measured, is 113.18 m3/d. The target rates of the ammonia nitrogen and the total phosphorus in the effluent were determined to be 0.5 mg/l. The first version of the solution was according to the horizontal and the other to the vertical filters. The main advantages of this this solution using aquatic plant root filters include a naturally replicated process of wastewater treatment and low operating costs. Also for these reasons, this green zone method is increasingly used for homes, holiday residences and communities

Some Slavic terms concerning the coppice

Etymology of the words lětina, lěs7 and g7lm7 in connection with the old practice of frequently cutting the underwood

Explanations of some Czech names of plants

The article gives semantic and etymologic explanation of following names of plants in Czech dialects: maselnice ´Orobanche alba´, smetaník ´Lathraea´, randlíček, rendličky ´Aquilegia´ and sníček ´Asplenium´

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