Factors controlling rock–clay buffer interaction in a radioactive waste repository
نویسندگان
چکیده
The paper examines the interaction between host rock and a clay-based engineered barrier in the context of deep underground disposal of high-level radioactive waste. A large scale ‘‘in situ’’ heating test currently under way in the underground Grimsel Rock Laboratory (GRL; Switzerland) is adopted as a representative case for study. The main features of the behaviour of the rock/barrier system have been examined using a comprehensive programme of coupled thermo–hydro– mechanical analyses. A parametric study has been performed to assess the effects of individual phenomena and parameters. The characterisation activities carried out in relation with the in situ test provide the information on material properties and test conditions required. Results highlighting the influence of vapour diffusion, permeability, and retention curve of rock and bentonite are presented. The interaction between clay barrier and host medium exhibits a high degree of complexity. D 2002 Elsevier Science B.V. All rights reserved.
منابع مشابه
Transient boundary conditions in the frame of THM-processes at nuclear waste repositories
In nuclear waste repositories, initially unsaturated buffer is subjected to constant heat emitted by waste canister in conjunction with peripheral hydration through water from host rock. The transient hydration process can be potraied as transformation of initial heterogeneity towards homogeneity as final stage. In this context, this paper addresses the key issue of hydro mechanical behaviour o...
متن کاملInverse Modeling of Gas, Water, and Heat Flow in Bentonite/crushed Rock Backfill
Swelling clays play a major role in current concepts for the underground disposal of high-level nuclear waste in deep geological formations. In one of the multi-barrier concepts for preventing the escape of radioactive substances from a high-level nuclear waste repository, the barrier consists of a copper container, compacted bentonite as buffer and backfill (the engineered barrier), and the re...
متن کاملCharacterization of Swelling Clays as Buffer/ Backfill Material for Geological Repositories of Immobilized Radioactive Liquid Waste
After gaining considerable expertise in establishing and exercising waste management strategy by immobilization of high-level radioactive liquid waste (HLW) in borosilicate glass matrix followed by its interim storage, it is envisaged to focus on geologic disposal of radioactive waste packages. The multi barrier disposal system is considered one of the options for isolation of radioactive waste...
متن کاملA minimalistic microbial food web in an excavated deep subsurface clay rock.
Clay rocks are being considered for radioactive waste disposal, but relatively little is known about the impact of microbes on the long-term safety of geological repositories. Thus, a more complete understanding of microbial community structure and function in these environments would provide further detail for the evaluation of the safety of geological disposal of radioactive waste in clay roc...
متن کاملSpeciation of neptunium during sorption and diffusion in natural clay
In argillaceous rocks, which are considered as a potential host rock for nuclear waste repositories, sorption and diffusion processes govern the migration behaviour of actinides like neptunium. For the safety analysis of such a repository, a molecular-level understanding of the transport and retardation phenomena of radioactive contaminants in the host rock is mandatory. The speciation of Np du...
متن کامل