Borehole DGR-3 and DGR-4 Porewater Investigations
Notice bibliographique
Résumé
Intera Engineering has been contracted by the Nuclear Waste Management Organization on behalf of Ontario Power Generation (OPG) to implement the Geoscientific Site Characterization Plan (GSCP) for the Bruce site located on Lake Huron, Ontario. The GSCP is described by Intera Engineering Ltd. (Intera, 2006; 2008a). The purpose of the site characterization work is to assess the suitability of the Bruce site to construct a Deep Geologic Repository (DGR) to store low-level and intermediate-level radioactive waste. This Technical Report (TR) presents the results of porewaters investigations conducted on formations sampled in boreholes DGR-3 and DGR-4. These results are integrated with porewater characterization work conducted on DGR-2 samples (Koroleva et al., 2009), building on the understanding obtained from this earlier research. The work described in this report was completed by the Rock-Water Interaction Group, University of Bern, Switzerland, under contract to Intera Engineering Ltd. In low porosity and permeability formations in the Palaeozoic sedimentary sequence at the Bruce site, direct sampling of porewaters is not feasible. Investigating the chemical composition of porewaters requires application of a suite of indirect techniques, each of which provides partial information. The understanding of porewater composition gained from the application of these techniques can be augmented with geochemical modelling. To determine the isotopic composition of the porewaters, the diffusive exchange technique originally developed and applied by Rubel et al. (2002) has been adapted by RWI over the course of DGR site characterization activities for application to formations containing highly saline porewaters. This method was initially developed for rocks containing pore water with salinities up to seawater. Significant developments were required to adapt the method to high salinity pore waters (e.g. Waber et al., 2007; de Haller et al., 2008; Koroleva et al., 2009). The most recent and complete adaptation of this method was applied to samples from DGR-4. To obtain information on the chemical compositions of the porewaters, results of aqueous extractions were evaluated together with mineralogical and petrophysical data to assess whether the extracted ions are predominantly from porewater or significantly influenced by water-rock reactions during the extractions. Where applicable, apparent porewater compositions were derived. As part of research on samples from DGR-3, ethanol-water extractions were also investigated as a potential technique for extracting porewater while minimizing mineral-water interactions during the extraction. The results of initial testing including extractions on pure mineral phases and on DGR-3 samples are presented in this report. Out-diffusion experiments have been performed on select formations, providing information on the pore diffusion coefficients for Cl-. Estimates of apparent Cl- porewater concentrations from these experiments are compared to those determined for aliquots of the same samples using aqueous extraction. The advective displacement technique (e.g. Mäder et al., 2004; Mäder, 2005) was also tested as a direct method for the extraction of porewater from a sample of the Cobourg Formation; the results to date are summarized in this report. In the final section of the report, the status of our understanding of the chemical and isotopic composition of porewaters is evaluated and an approach for reconstructing porewater compositions using geochemical equilibrium modelling is presented.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».