Experimental assessment of the gas permeability of engineered barriers in a deep geological repository – Final Report

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F19%3A00350702" target="_blank" >RIV/68407700:21110/19:00350702 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Experimental assessment of the gas permeability of engineered barriers in a deep geological repository – Final Report

Original language description

The aim of the “Experimental assessment of the gas permeability of engineered barriers in a deep geological repository” subproject was to launch, based on a detailed literature review, an experimental programme for the assessment of the gas permeability of the EBS considered for the future Czech DGR. An initial experimental analysis was performed of the behaviour of gases in the engineered barrier material involving the experimental investigation of bentonite and its self-healing ability. The study was divided into two main areas: a. The gas permeability of bentonite with natural water content b. Gas breakthrough in saturated bentonite The results of both areas of the study clearly revealed that the main determinant of the behaviour of BaM material in terms of gas permeability consists of its dry density. The results obtained from the gas breakthrough tests did not indicate that cyclical gas breakthrough events degrade the material. Whereas in some cases a deterioration in properties was evident, the changes eventually stabilised and were not significant. Conversely, the hydraulic conductivity and swelling pressure values were, in most cases, systematically better than the reference values. The results revealed the significant influence of time. This was particularly evident for the samples with discontinuities. Although the permeability and swelling pressure values did not vary significantly over time, the process of the stabilisation of the breakthrough values lasted significantly longer and, moreover, the behaviour of the material under test conditions differed. The gas permeability tests conducted as part of this project were of a pilot character. The breakthrough tests revealed the non-deterministic behaviour of the material and the significant need for the conducting of long-term tests. The gradual upscaling of the issue is required. Moreover, the experimental analysis did not address materials that are inhomogeneous due to their form (i.e. pellets).

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20101 - Civil engineering

Project

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Continuities

N - Vyzkumna aktivita podporovana z neverejnych zdroju

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů