Chemical characterisation and modelling of the interstitial fluid in the Boom clay formation

2021 ◽  
pp. 779-782
Author(s):  
C. Beaucaire ◽  
P. Toulhoat ◽  
H. Pitsch
Keyword(s):  
Interstitial Fluid ◽  
Boom Clay ◽  
Clay Formation

Twenty-five years' geotechnical observation and testing in the Tertiary Boom Clay formation

Géotechnique ◽  
2007 ◽  
Vol 57 (2) ◽  
pp. 229-237 ◽  
Author(s):  
F. Bernier ◽  
X. L. Li ◽  
W. Bastiaens
Keyword(s):  
Boom Clay ◽  
Clay Formation

Modelling Transport of 14 C-Labelled Natural Organic Matter (NOM) in Boom Clay

2008 ◽  
Vol 1107 ◽  
Author(s):  
Alice Ionescu ◽  
Norbert Maes ◽  
Dirk Mallants
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Water Movement ◽  
Numerical Code ◽  
Migration Behavior ◽  
Colloidal Transport ◽  
Boom Clay ◽  
Kinetically Controlled ◽  
Clay Formation ◽  
Hydrus 1D

AbstractIn Belgium, the Boom Clay formation is considered to be the reference formation for HLW disposal R&D. Assessments to date have shown that the host clay layer is a very efficient barrier for the containment of the disposed radionuclides. Due to absence of significant water movement), diffusion - the dominant transport mechanism, combined with generally high retardation of radionuclides, leads to extremely slow radionuclide migration. However, trivalent lanthanides and actinides form easily complexes with the fulvic and humic acids which occur in Boom Clay and in its interstitial water. Colloidal transport may possibly result in enhanced radionuclide mobility, therefore the mechanisms of colloidal transport must be better understood. Numerical modeling of colloidal facilitated radionuclide transport is regarded an important means for evaluating its importance for long-term safety.The paper presents results from modeling experimental data obtained in the framework of the EC TRANCOM-II project, and addresses the migration behavior of relevant radionuclides in a reducing clay environment, with special emphasis on the role of the Natural Organic Matter (NOM) [1]. Percolation type experiments, using stable 14C-labelled NOM, have been interpreted by means of the numerical code HYDRUS-1D [2]. Tracer solution collected at regular intervals was used for inverse modeling with the HYDRUS-1D numerical code to identify the most likely migration processes and the associated parameters. Typical colloid transport submodels tested included kinetically controlled attachment/detachment and kinetically controlled straining and liberation.

scholarly journals A partial braincase and other skeletal remains of Oligocene angel sharks (Chondrichthyes, Squatiniformes) from northwest Belgium, with comments on squatinoid taxonomy

2016 ◽  
Vol 85 (2) ◽  
pp. 147-171 ◽  
Author(s):  
Frederik H. Mollen ◽  
Barry W.M. van Bakel ◽  
John W.M. Jagt
Keyword(s):  
Comparative Anatomy ◽  
Interspecific Variation ◽  
Molecular Study ◽  
Shark Species ◽  
Southwest Atlantic ◽  
Boom Clay ◽  
Shark Teeth ◽  
Modern Species ◽  
Differential Characters ◽  
Clay Formation

A detailed redescription of a chondrocranium from the basal Boom Clay Formation (Rupelian, Upper Oligocene) at the SVK clay pit, Sint-Niklaas (province of Oost-Vlaanderen, Belgium), previously assigned to the sawshark Pristiophorus rupeliensis, is presented. The chondrocranium is re-identified as that of an angel shark (Squatinidae), based on comparative anatomy of extant Squatina, inclusive of CT scans of Squatina africana, S. australis, S. dumeril, S. guggenheimand S. squatina, with different geographic distributions and representing all four angel shark clades as defined in a previous molecular study. Differential characters for chondrocrania listed in earlier accounts to discriminate angel shark species from the southwest Atlantic proved to be even more revealing when comparing angel sharks from different regions/clades. Despite this wide interspecific variation, the fossil chondrocranium compares well with modern Squatina, but differs in having a UUU-shaped ventral margin of the occipital region and rounded margins of the upper postorbital processes. The distal expansion of the upper postorbital processes present in modern species has not yet been observed in extinct squatinoids and might constitute a derived character for modern representatives only. Angel shark teeth and vertebrae are well known from the same basal deposit at the SVK clay pit, but Cenozoic squatinid taxonomy remains problematic. It is here discussed in detail for the Oligocene taxa S. angeloides, S. rupeliensisand S. beyrichi. For the time being, all SVK material is left in open nomenclature and referred to as Squatinasp.

scholarly journals Magnetostratigraphy and rock magnetism of the Boom Clay (Rupelian stratotype) in Belgium

2004 ◽  
Vol 83 (3) ◽  
pp. 209-225 ◽  
Author(s):  
D. Lagrou ◽  
N. Vandenberghe ◽  
S. Van Simaeys ◽  
J. Hus
Keyword(s):  
Rock Magnetism ◽  
Magnetic Polarity ◽  
Magnetic Minerals ◽  
Boom Clay ◽  
Physical Relation ◽  
Magnetic Remanence ◽  
Natural Remanent Magnetisation ◽  
Iron Sulphides ◽  
Magnetic Techniques ◽  
Clay Formation

AbstractThis paper presents the results of a detailed rock magnetic and magnetostratigraphic study of the Lower Oligocene Rupelian unit-stratotype. Notwithstanding the relatively low intensity of the natural remanent magnetisation and the diverse and often unstable behaviour during demagnetisation, close-spaced sampling and accurate polarity determinations allowed us to determine the magnetic polarity zonation. The recognition of the characteristic magnetic polarity and the correlation with the standard magnetobiochronologic time scale yields an accurate chronostratigraphic dating of the Boom Clay Formation. The boundary between the geomagnetic chrons C12n and C12r nearly coincides with the lithostratigraphic boundary between theTerhagen and Putte Members. Rock magnetic techniques point to magnetite and probably also iron sulphides as the main magnetic remanence carriers. These magnetic minerals could, however, not be identified with classical mineralogical techniques performed on magnetic extractions. The failure to detect them may be due to the low concentration of these minerals, the small grain size, and the close physical relation with pyrite.

scholarly journals Hollow Cylinder Simulation Experiments of Galleries in Boom Clay Formation

2013 ◽  
Vol 47 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Vincent Labiouse ◽  
Claire Sauthier ◽  
Shuang You
Keyword(s):  
Hollow Cylinder ◽  
Simulation Experiments ◽  
Boom Clay ◽  
Clay Formation

PROCESSING OF SEISMIC DIFFRACTIONS FROM CARBONATE NODULES IN CLAY FORMATIONS

Geophysics ◽  
2021 ◽  
pp. 1-64
Author(s):  
Cinzia Bellezza ◽  
Flavio Poletto ◽  
Biancamaria Farina ◽  
Giorgia Pinna ◽  
Laurent Wouters ◽  
...  
Keyword(s):  
High Resolution ◽  
Seismic Reflection ◽  
Synthetic Data ◽  
Seismic Profile ◽  
Radioactive Waste Disposal ◽  
Small Scale ◽  
Boom Clay ◽  
Seismic Image ◽  
Imaging Results ◽  
Clay Formation

The problem of localizing small (relative to wavelength) scatterers by diffractions to enhance their use in identifying small-scale details in a seismic image is extremely important in shallow exploration, to identify interesting features such as fractures, caves and faults. The conventional approach based on seismic reflection is limited in resolution by the Rayleigh criterion. In certain acquisition geometries, such as crosswell surveys aimed at obtaining high resolution signals, the availability of suitable datasets for effective migration depends on the spatial extent of the available source and receiver data intervals. With the aim of overcoming the resolution limits of seismic reflection, we studied the detectability, response, and location of meter- and possibly sub-meter-dimension carbonate concretions (septaria) in the Boom Clay Formation (potential host rocks for radioactive waste disposal) by diffraction analysis of high-frequency signals. We investigated diffraction wavefields by signal separation, focusing, and high-resolution coherency analysis using the MUltiple Signal Classification (MUSIC) method and semblance. The investigation was performed for two different surveys in Belgium, a shallow and high resolution Reverse Vertical Seismic Profile (RVSP) and a near-offset crosswell application at Kruibeke and ON-MOL-2 sites, respectively. The data analysis is supported by synthetic wavefield modeling. The multi-offset RVSP provides the appropriate geometry to observe and investigate the septaria diffractions both from depth and the surface. The crosswell approach, calibrated using synthetic data in the analysis of wavefield patterns in 2D, shows promising imaging results with field data of a selected diffraction zone in the interwell area.

Static dissolution tests of α-doped UO2 under repository relevant conditions: Influence of Boom Clay and α-activity on fuel dissolution rates

2006 ◽  
Vol 932 ◽  
Author(s):  
Sonia Salah ◽  
Christelle Cachoir ◽  
Karel Lemmens ◽  
Norbert Maes
Keyword(s):  
Clay Fraction ◽  
Dissolution Kinetics ◽  
Spent Fuel ◽  
Dissolution Rates ◽  
Retention Capacity ◽  
Boom Clay ◽  
Dissolution Tests ◽  
Clay Formation ◽  
Α Activity

ABSTRACTSince reprocessing is no longer the reference policy in Belgium, studies on the direct disposal of spent fuel in a clay formation have gained increased interest in the last years. In order to determine to what extent the clay properties and the α-activity influence the dissolution kinetics of spent fuel for the long term disposal, static dissolution tests have been performed on 5 different types of α-doped UO2, representing a PWR fuel with a burn-up of 45 or 55 GWd · tHM−1 and fuel ages ranging between 150 and 90,000 years, in different Boom Clay (BC) media at room temperature and in an anoxic atmosphere for 90 to 720 days. The uranium activity in the clay fraction over time was found to be much higher than the U-activity in the leachates, which has been mainly ascribed to the high retention capacity of the BC. The average dissolution rate between 0 and 90 days obtained for the 5 types of α-doped UO2 were all found to be high and quite similar at ~263 µg · m−2 · d−1and a “longer-term” rate (181 to 720 days) ranging between zero and 15 µg · m−2· d−1. These results suggest that the activity of the fuels does not seem to have an effect on the UO2 dissolution rates under the considered test conditions. In order to study the partition/redistribution of U during UO2dissolution, sequential extraction experiments were performed. Results of the latter have provided a better mechanistic understanding of BC/spent fuel interaction processes as well as information on the role of the different minerals controlling the U-retention/immobilization.

Corrosion Behavior of High Burnup Spent Fuel in Highly Alkaline Solutions

2009 ◽  
Vol 1193 ◽  
Author(s):  
A. Loida ◽  
R. Gens ◽  
V. Metz ◽  
K. Lemmens ◽  
C. Cachoir ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Waste Product ◽  
Alkaline Solutions ◽  
Spent Fuel ◽  
Boom Clay ◽  
Matrix Bound ◽  
Engineered Barriers ◽  
Clay Formation ◽  
Fractional Release

AbstractThis study is focused on the alteration behavior of spent nuclear fuel when exposed to highly alkaline groundwater. Contact of highly alkaline solution with the waste product is considered in the Belgian concept for disposal in the Boom Clay formation. According to the “supercontainer design” the fuel will be encapsulated in carbon steel canisters, surrounded by a concrete over-pack. After saturation of the engineered barriers by porewater, interactions with the concrete will result in solutions rich in NaOH, KOH and Ca(OH)2. Using this type of solution at pH 12.5, spent nuclear fuel corrosion experiments were conducted over 378 days. Under anoxic conditions, parallel experiments were performed (a) in the absence of Fe phases and (b) in the presence of solid Fe phases representing container (corrosion) products. Both types of experiments resulted in relatively low matrix dissolution rates, around 10-7 per day, according to the fractional release of Sr. Solution concentrations of actinides are close to or below the detection limit, indicating an effective retention of these radioelements in the system. The observed precipitation of a Ca rich phase onto the surfaces of the corroded fuel samples may be related to the inhibited re-lease of actinides, Sr and other matrix bound radioelements.

Safety Assessment of Geological Disposal of High-Level Radioactive Waste in Boom Clay: Relation With the Radionuclide Inventory

2009 ◽  
Author(s):  
Pierre Van Iseghem ◽  
Jan Marivoet
Keyword(s):  
Radioactive Waste ◽  
Safety Assessment ◽  
High Level Waste ◽  
Spent Fuel ◽  
Geological Disposal ◽  
High Level Radioactive Waste ◽  
Boom Clay ◽  
High Level ◽  
Clay Formation ◽  
Parameter Values

This paper discusses the impact of the parameter values used for the transport of radionuclides from high-level radioactive waste to the far-field on the long-term safety of a proposed geological disposal in the Boom Clay formation in Belgium. The methodology of the Safety Assessment is explained, and the results of the Safety Assessment for vitrified high-level waste and spent fuel are presented. The radionuclides having the strongest impact on the dose-to-man for both HLW glass and spent fuel are 79Se, 129I, 126Sn, 36Cl, and 99Tc. Some of them are volatile during the vitrification process, other radionuclides are activation products, and for many of them there is no accurate information on their inventory in the waste form. The hypotheses in the selection of the main parameter values are further discussed, together with the status of the R&D on one of the main dose contributing radionuclides (79Se).

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