Engineered barrier 200C

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F23%3A00366524" target="_blank" >RIV/68407700:21110/23:00366524 - isvavai.cz</a>

Result on the web

<a href="https://guarant.eu/ucprague/proceedings/2023/data/en/fullpapers/uc-2023-session-5-poster-11-svoboda.pdf" target="_blank" >https://guarant.eu/ucprague/proceedings/2023/data/en/fullpapers/uc-2023-session-5-poster-11-svoboda.pdf</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Engineered barrier 200C

Original language description

All countries that operate nuclear reactors are faced with the issue of the disposal of nuclear waste. To date, the only safe and technically possible approach to this issue is the construction of deep geological repositories (DGR). The DGR disposal system is based on the multi-barrier principle, which, in the Czech case, will involve the disposal of the waste in double-walled waste disposal packages (WDP), which will then be surrounded in the disposal well by a bentonite sealing layer - the so-called engineered barrier. The final barrier of the system comprises the host rock environment. The Czech repository concept, as with other concepts worldwide, and the related research has, until recently, focused on temperatures of up to 100°C (the temperature on the surface of the WDP). However, if it were possible to consider higher temperatures on the surface of the WDP, it would lead to significant financial savings due to the potential to achieve a higher WDP disposal density. The Engineered barrier 200C project is, therefore, concerned with the research of the behaviour of the engineered barrier at elevated temperatures (150°C–200°C). The objective is to use the results of a long-term in-situ experiment and the accompanying research to critically evaluate the resistance of the bentonite barrier at higher temperatures. In addition to potential significant financial savings due to the higher disposal density, safety would be enhanced via the availability of more accurate input for the safety analysis since important insight would be obtained into the behaviour of the engineered barrier materials and the disposal system as a whole. Such insight would be relevant to both the current and the high-temperature concepts. The project is being conducted via the multidisciplinary approach (geotechnics, geochemistry, mineralogy, microbiology) and includes comprehensive research on the behaviour of the bentonite barrier both in-situ and under laboratory conditions. Czech BCV bentonite is being used in both the in-situ experiments and the laboratory research. With concern to the laboratory research, the bentonite is being subjected to long-term loading at a temperature of 200°C, and its properties (mineralogical changes, permeability, swelling pressure, etc.) are verified at regular time intervals. Thus, data is being obtained for the creation of a database of the material characteristics, which will subsequently be used for the creation of a THM mathematical model. The in-situ physical model simulates a vertical disposal site in a DGR; it is located in a borehole of D=0.75 m (h=°~2 m). A heater, which simulates the heat produced by the disposed of nuclear fuel, has been positioned inside the model and is subjecting the surrounding engineered barrier (made of pelletised bentonite) to a temperature of 200°C. The experiment is being monitored and sampling is performed at regular intervals.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20101 - Civil engineering

Project

<a href="/en/project/TK01030031" target="_blank" >TK01030031: Engineered barrier 200C</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2023

Confidentiality

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

Article name in the collection

Proceedings of the 15th International Conference “Underground Construction Prague 2023”

ISBN

978-80-906452-5-7

ISSN

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e-ISSN

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Number of pages

14

Pages from-to

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Publisher name

Česká tunelářská asociace ITA-AITES

Place of publication

Praha

Event location

Praha

Event date

May 29, 2023

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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