Flow and Tracer Experiments in Crystalline Rocks: Results from Several Swedish in Situ Experiments

1985 ◽  
Vol 50 ◽  
Author(s):  
H. Abelin ◽  
L. Birgersson ◽  
J. Gidlund ◽  
L. Moreno ◽  
I. Neretnieks ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Crystalline Rock ◽  
Crystalline Rocks ◽  
Flow And Transport ◽  
In Situ Experiments ◽  
Tracer Experiments

In a final repository for radioactive waste in crystalline rock, water flowing in the fractures may transport the radionuclides eventually leached from the waste. To be able to predict the migration of the radionuclides the processes involved must be understood. To quantify the processes, data from flow and transport in real fractures under realistic conditions are needed. Models used for prediction must include descriptions of the important processes and mechanisms.

Aqueous Phase Diffusion in Crystalline Rock

1981 ◽  
Vol 11 ◽  
Author(s):  
M.H. Bradbury ◽  
D. Lever ◽  
D. Kinsey
Keyword(s):  
Radioactive Waste ◽  
Aqueous Phase ◽  
Water Movement ◽  
Degradation Products ◽  
Crystalline Rock ◽  
Crystalline Rocks ◽  
Radionuclide Transport ◽  
Fracture Networks ◽  
Phase Diffusion ◽  
Main Factors

One of the options being considered for the disposal of radioactive waste is deep burial in crystalline rocks such as granite. It is generally recognised that in such rocks groundwater flows mainly through the fracture networks so that these will be the “highways” for the return of radionuclides to the biosphere. The main factors retarding the radionuclide transport have been considered to be the slow water movement in the fissures over the long distances involved together with sorption both in man-made barriers surrounding the waste, and onto rock surfaces and degradation products in the fissures.

ÚJV Řež, a.s. Research Programme Supporting Development of Deep Geological Repository in the Czech Republic

2014 ◽  
Author(s):  
Václava Havlová
Keyword(s):  
Czech Republic ◽  
Radioactive Waste ◽  
Research Programme ◽  
Deep Geological Repository ◽  
The Czech Republic ◽  
Reducing Conditions ◽  
In Situ Experiments ◽  
Geological Repository

ÚJV Řež, a.s. as a company with a long term experience in radioactive waste management (RWM) has been running a comprehensive research programme, supporting development of deep geological repository (DGR) in the Czech Republic. Recently ÚJV Řež, a.s. research has focused on the different aspects of safety functions that DGR barriers should provide. Moreover, the research has also recently paid strong attention to real conditions that can be present in DGR (anaerobic reducing conditions, increased T due to heat generation by radioactive waste, contact of different materials within repository, real scale of the rock massive etc.). Both types of experiments, laboratory and in-situ experiments in underground laboratories, were included in the research programme. The presentation gives a brief overview of experimental trends, being conducted for materials and conditions, concerned in Czech repository concept.

Altered Crystalline Rock Distributed Along Groundwater Conductive Fractures and the Retardation Capacity in the Orogenic Field of Japan

2009 ◽  
Author(s):  
Hidekazu Yoshida ◽  
Shoji Nishimoto ◽  
Richard Metcalfe
Keyword(s):  
Radioactive Waste ◽  
Barrier Function ◽  
Chemical Characterization ◽  
Crystalline Rock ◽  
Crystalline Rocks ◽  
Rock Interaction ◽  
Physico Chemical ◽  
High Level ◽  
A Site ◽  
Accessible Porosity

In the orogenic field Japanese islands, there are wide areas of crystalline rocks that inevitably contain groundwater conductive fractures associated with alteration zones. However, little attention has been given to the formation process and possible influence on the radionuclides migration from radioactive waste repository that might be sited within crystalline rock. In particular, the influences of alteration minerals and microfractures, due to chemical sorption and/or physical retardation are required to assess the realistic barrier function. In order to understand the alteration process and the retardation capacity, detailed mineralogical and physico-chemical characterization of altered crystalline rocks have been carried out. Mineralogical analysis reveals that the altered crystalline rocks have been formed through basically two stages of water-rock interaction during and after uplift. Physico-chemical characteristics including laboratory sorption experiments show that altered crystalline rock has a certain volume of accessible porosity, particularly in plagioclase grains, which would influence on nuclide retardation more than the accessible porosity in other minerals present, such as biotite. These results provide confidence that even altered and fractured parts of any crystalline rock that might be encountered in a site for the disposal of high-level radioactive waste may still play a role of barrier function.

Mechanical and SCC Behavior of an API5L Steel Casing Within the Context of Deep Geological Repositories for Radioactive Waste

2015 ◽  
Author(s):  
F. Bumbieler ◽  
S. Necib ◽  
J. Morel ◽  
D. Crusset ◽  
G. Armand
Keyword(s):  
Radioactive Waste ◽  
Host Rock ◽  
Mechanical Load ◽  
Early Stage ◽  
High Yield ◽  
General Corrosion ◽  
Short Term ◽  
In Situ Experiments ◽  
Deep Geological Repositories

Andra, the French national radioactive waste management agency, is in charge of studying the possibility of disposal of High Level activity Wastes (HLW) in deep geological repositories. The concept of HLW cells consists of horizontal micro-tunnels of about 0.7 m in diameter, equipped with a steel casing. In order to ensure the reliability of the casing, particularly with respect to Stress Corrosion Cracking (SCC), several in-situ experiments dedicated to the analysis of its short term mechanical and corrosion behavior have been performed at Andra’s Underground Research Laboratory (URL) as well as in surface laboratory. Reduced and full scale in-situ experiments consisting of equipping boreholes parallel to the major horizontal stress (σH) with instrumented steel tubing, have been performed to analyze the mechanisms involved in the casing/rock interface. The main characteristics of the short term mechanical load applied by the rock have been determined from local strain and convergence measurements. Although in-situ stress is isotropic in the section of boreholes parallel to σH, measurements exhibit a strongly anisotropic load. SCC experiments conducted on different steel grades, in contact with the clay host rock containing CO2/H2 revealed that general corrosion is the main type of corrosion expected for steel casings. However, the selected steel casing must have a sufficiently high yield strength (above 400 MPa) to reduce the risk of early stage plasticity due to host rock anisotropic convergence and thus to overcome SCC. API5LX65 steel seems to meet both mechanical and corrosion requirements, therefore being likely the appropriate material for the manufacture of the casing.

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