scholarly journals Thermal properties of engineered barriers for a Canadian deep geological repository

2018 ◽  
Vol 55 (6) ◽  
pp. 759-776 ◽  
Author(s):  
Pedram Abootalebi ◽  
Greg Siemens
Keyword(s):  
Thermal Properties ◽  
Thermal Property ◽  
Nuclear Fuel ◽  
Nuclear Power ◽  
Spent Nuclear Fuel ◽  
Numerical Models ◽  
Deep Geological Repository ◽  
Barrier Materials ◽  
Physical Measurements ◽  
Geological Repository

Global energy needs continue to rise along with society’s desire for carbon-reduced energy sources to limit climate change effects. One viable carbon-reduced energy source is nuclear power, which provides more than half the electricity requirements of the province of Ontario. Within Canada there are more than 2.5 million bundles of spent nuclear fuel, which will be stored in a deep geological repository. Efficiency of the repository system depends on dissipation of thermal energy. A comprehensive experimental study is presented on thermal properties of barrier materials. The influence of bentonite type, variability, moisture, and temperature on thermal properties is examined. Results show strong influence of moisture on thermal properties, some influence of temperature on low-density bentonite, minor influence of bentonite type, as well as low variability in the experimental measurements. The extensive database of physical measurements is compared with values from the literature and then used to statistically evaluate thermal property models selected from the literature. Using the base parameters from the literature, thermal property models performed adequately; however, soil-specific calibration of the model inputs improved the fit significantly. These results are now available to perform the numerical models for the proposed Canadian deep geological repository for used nuclear fuel.

scholarly journals Seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 486-493
Author(s):  
Zdeněk Kaláb ◽  
Jan Šílený ◽  
Markéta Lednická
Keyword(s):  
Czech Republic ◽  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Probabilistic Method ◽  
Seismic Stability ◽  
Historical Period ◽  
Deep Geological Repository ◽  
The Czech Republic ◽  
Geological Repository ◽  
The Impact

AbstractThis paper deals with the seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel in the Czech Republic. The basic source of data for historical earthquakes up to 1990 was the seismic website [10]. The most intense earthquake described occurred on September 15, 1590 in the Niederroesterreich region (Austria) in the historical period; its reported intensity is Io = 8-9. The source of the contemporary seismic data for the period since 1991 to the end of 2014 was the website [11]. It may be stated based on the databases and literature review that in the period from 1900, no earthquake exceeding magnitude 5.1 originated in the territory of the Czech Republic.In order to evaluate seismicity and to assess the impact of seismic effects at depths of hypothetical deep geological repository for the next time period, the neo-deterministic method was selected as an extension of the probabilistic method. Each one out of the seven survey areas were assessed by the neo-deterministic evaluation of the seismic wave-field excited by selected individual events and determining the maximum loading.Results of seismological databases studies and neo-deterministic analysis of Čihadlo locality are presented.

scholarly journals Radiation Effects on Materials Used in Geological Repositories for Spent Nuclear Fuel

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Mats Jonsson
Keyword(s):  
Ionizing Radiation ◽  
Nuclear Fuel ◽  
Nuclear Power ◽  
Power Plants ◽  
Spent Nuclear Fuel ◽  
Safety Analysis ◽  
Nuclear Industry ◽  
Barrier Materials ◽  
Materials Used

Safe long-term storage of radioactive waste from nuclear power plants is one of the main concerns for the nuclear industry as well as for governments in countries relying on electricity produced by nuclear power. A repository for spent nuclear fuel must be safe for extremely long time periods (at least 100 000 years). In order to ascertain the long-term safety of a repository, extensive safety analysis must be performed. One of the critical issues in a safety analysis is the long-term integrity of the barrier materials used in the repository. Ionizing radiation from the spent nuclear constitutes one of the many parameters that need to be accounted for. In this paper, the effects of ionizing radiation on the integrity of different materials used in a granitic deep geological repository for spent nuclear fuel designed according to the Swedish KBS-3 model are discussed. The discussion is primarily focused on radiation-induced processes at the interface between groundwater and solid materials. The materials that are discussed are the spent nuclear fuel (based on UO2), the copper-covered iron canister, and bentonite clay. The latter two constitute the engineered barriers of the repository.

New Perspectives for the Spent Nuclear Fuel Radionuclides Release Model in a Deep Geological Repository

2006 ◽  
Vol 985 ◽  
Author(s):  
Christophe Poinssot ◽  
Cécile FERRY ◽  
Arnaud POULESQUEN
Keyword(s):  
Nuclear Fuel ◽  
Source Term ◽  
Spent Nuclear Fuel ◽  
Deep Geological Repository ◽  
Term Evolution ◽  
Geological Repository ◽  
Definition Of ◽  
Release Model ◽  
The Impact

AbstractSpent Nuclear Fuel (SNF) source terms are used to define the release rate of radionuclides (RN) in a direct disposal and to assess the performance of this waste form. They classically distinguish between two contributions: (i) the Instant Release Fraction (IRF) of RN which are directly leached when water contacts the fuel, (ii) the slow and long term release of RN which are embedded within the fuel matrix. Recent experimental results bring significant input in our understanding and assessment of both contributions. However, they have not yet been integrated in the definition of the SNF source term. This paper will present the impact on the RN source term of the latest results on the SNF long term evolution and the key remaining scientific issues.

scholarly journals Oxidation of UO2(s) in aqueous solution

2008 ◽  
Vol 6 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Olivia Roth ◽  
Mats Jonsson
Keyword(s):  
Steady State ◽  
Nuclear Fuel ◽  
Kinetic Data ◽  
Safety Assessment ◽  
Spent Nuclear Fuel ◽  
Deep Geological Repository ◽  
Elementary Processes ◽  
Oxidant Concentration ◽  
Geological Repository ◽  
Experimental Values

AbstractIn this review the kinetics and mechanism of oxidative dissolution of UO2(s), mainly under conditions of relevance for the safety assessment of a deep geological repository for spent nuclear fuel, are discussed. Rate constants for the elementary processes involved (oxidation of UO2 and dissolution of oxidized UO2) are used to calculate the rates of oxidative UO2(s) dissolution under various conditions (type of oxidant, oxidant concentration and HCO3−/CO32− concentration) for which experimental data are also available. The calculated rates are compared to the corresponding experimental values under the assumption that the experimental numbers reflect the steady-state conditions of the system. The agreement between the calculated rates and the corresponding experimental ones is very good, in particular for the higher rates. In general, the calculated rates are somewhat higher than the experimental numbers. This can be due partly to the use of initial concentrations rather than steady-state concentrations in the calculations. The kinetic data are also used to quantitatively discuss the dynamics of spent nuclear fuel dissolution under deep geological repository conditions.

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