BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Porosity distribution in a heterogeneous clay-rich fault core DTSTART;VALUE=DATE-TIME:20171102T031500Z DTEND;VALUE=DATE-TIME:20171102T033000Z DTSTAMP;VALUE=DATE-TIME:20260718T063601Z UID:indico-contribution-345-1203@events01.synchrotron.org.au DESCRIPTION:Speakers: Ville Nenonen (University of Helsinki)\nFault zones influence the mechanical properties and seismological behaviour of the Ear th’s crust and also the migration and trapping of sub-surface fluids. In addition to natural processes\, their behaviour has broad implications to issues such as oil and gas production\, the sequestration of carbon dioxi de and the geological disposal of radioactive wastes. \nRecent investigati ons carried out at the Tournemire Underground Laboratory (URL)\, run by th e French Institute for Radiological Protection and Nuclear Safety (IRSN) h ave highlighted heterogeneous fault gouge strengthening processes within a small-scale vertical strike slip fault affecting a low-permeability shale . \nThe aim of this project is to determine precisely\, in an apparently h eterogeneous and poorly consolidated brecciated rock\, the porosity variat ions in and around the different fault gouges and define their relationshi p to chemical and/or mechano-chemical processes.\n\nhttps://events01.synch rotron.org.au/event/51/contributions/1203/ LOCATION: URL:https://events01.synchrotron.org.au/event/51/contributions/1203/ END:VEVENT BEGIN:VEVENT SUMMARY:Effect of thiosulfate on the SCC behavior of carbon steel welds ex posed to concrete pore water under anoxic conditions DTSTART;VALUE=DATE-TIME:20171102T023000Z DTEND;VALUE=DATE-TIME:20171102T030000Z DTSTAMP;VALUE=DATE-TIME:20260718T063601Z UID:indico-contribution-345-1200@events01.synchrotron.org.au DESCRIPTION:Speakers: Sebastien CAES (SCK-CEN)\nThe Supercontainer (SC) is the reference concept for the post-conditioning of vitrified high-level n uclear waste and spent fuel in Belgium. It comprises a prefabricated concr ete buffer that completely surrounds a carbon steel overpack. Welding is b eing considered as a final closure technique of the carbon steel overpack in order to ensure its water tightness. Welding is known to induce residua l stresses near the weld zone\, which may lead to an increased susceptibil ity to stress corrosion cracking (SCC). In this study\, slow strain rate t ests were conducted to study the SCC behavior of plain and welded P355 QL2 grade carbon steel exposed to an artificial concrete pore water solution that is representative for the SC concrete buffer environment. The tests w ere performed at 140°C\, a constant strain rate of 5 × 10-7 s-1 and at o pen circuit potential under anoxic conditions. The effect of thiosulfate o n the SCC behavior was investigated up to levels of 5.35 mM S2O32- (600 mg L-1).\n\nhttps://events01.synchrotron.org.au/event/51/contributions/1200/ LOCATION: URL:https://events01.synchrotron.org.au/event/51/contributions/1200/ END:VEVENT BEGIN:VEVENT SUMMARY:Effect of Carbonate on Lanthanides Migration Behavior in Compacted Bentonite DTSTART;VALUE=DATE-TIME:20171102T041500Z DTEND;VALUE=DATE-TIME:20171102T043000Z DTSTAMP;VALUE=DATE-TIME:20260718T063601Z UID:indico-contribution-345-1199@events01.synchrotron.org.au DESCRIPTION:Speakers: Kazuya Idemitsu (Kyushu university)\nThe apparent di ffusion coefficients of La\, Nd\, Eu\, Dy\, Er and Lu in compacted bentoni tes were investigated in various bicarbonate concentration. The apparent d iffusion coefficients of lanthanides tended to decrease with increase of d ry density. In the lower bicarbonate conditions than 0.25 M lanthanum had the largest diffusion coefficient of ca. 10-13 m2/s at 1.0 Mg/m3 and diffu sion coefficient was small as atomic number becomes big. On the other hand in the higher bicarbonate conditions than 0.25 M Lutetium had the largest diffusion coefficient and diffusion coefficient was small as atomic numbe r becomes small. Especially Lanthanum and Neodymium had smaller diffusion coefficient than 10-14 m2/s even at 1.0 Mg/m3. Diffusion coefficient of Eu ropium was around 10-13 m2/s at 1.0 Mg/m3 and less influence of bicarbonat e concentration. Diffusion coefficient of Lutetium increased from 2 x 10- 14 to 10-12 m2/s with bicarbonate concentration up to 1.0 M.\n\nhttps://ev ents01.synchrotron.org.au/event/51/contributions/1199/ LOCATION: URL:https://events01.synchrotron.org.au/event/51/contributions/1199/ END:VEVENT BEGIN:VEVENT SUMMARY:Behaviour of sand-bentonite buffer material of deep geological rep ository under high confining pressure DTSTART;VALUE=DATE-TIME:20171102T033000Z DTEND;VALUE=DATE-TIME:20171102T034500Z DTSTAMP;VALUE=DATE-TIME:20260718T063601Z UID:indico-contribution-345-1184@events01.synchrotron.org.au DESCRIPTION:Speakers: Janaka J. Kumara (Department of Civil Engineering\, Meijo University\, Japan)\nDeep geological repositories have been proposed as a safe waste management system for high-level radioactive wastes. Sand -bentonite buffer materials are used in engineered barrier system of deep geological facilities thank to their excellent swelling properties. In thi s research\, volumetric and strength behaviour of sand-bentonite buffer ma terial under high confining pressures of 1-3MPa were studied using a newly developed double-cell triaxial testing apparatus. The specimens were prep ared with 30% of sand as proposed for geological repositories in Japan. Th e suction behaviour of sand-bentonite specimens were also studied.\n Th e results indicate that the degree of saturation influences the strength a nd volumetric behaviour significantly\, which suggests that local groundwa ter flow affects the performance of buffer material upon decommissioning o f a deep geological repository. It also indicates that suction behavior is significantly affected by the degree of saturation\, although it was less affected by confining pressure.\n\nhttps://events01.synchrotron.org.au/ev ent/51/contributions/1184/ LOCATION: URL:https://events01.synchrotron.org.au/event/51/contributions/1184/ END:VEVENT BEGIN:VEVENT SUMMARY:Best Practice in the Management of Site Investigations for Geologi cal Disposal Facilities DTSTART;VALUE=DATE-TIME:20171102T044500Z DTEND;VALUE=DATE-TIME:20171102T050000Z DTSTAMP;VALUE=DATE-TIME:20260718T063601Z UID:indico-contribution-345-1164@events01.synchrotron.org.au DESCRIPTION:Speakers: Paul Degnan (Catalystra)\nThe disposal of intermedia te- and high-level radioactive waste requires emplacement in suitably engi neered underground facilities in order to ensure an adequate level of isol ation and containment for safety and security. We now have several example s of radioactive waste management organisations who have designed and unde rtaken extensive multi-disciplinary site investigation projects to charact erise environments for waste disposal in geological formations. However\, many countries requiring such facilities are still to initiate their own i nvestigations. It is therefore timely to compile lessons learnt on the man agement of site investigations for geological disposal facilities in order to support the sharing of knowledge and provide a platform for well-plann ed investigations to be undertaken in the future. Consequently\, this pres entation identifies important considerations associated with the planning and implementation of requirements-driven site investigation projects for geological radioactive waste disposal facilities.\n\nhttps://events01.sync hrotron.org.au/event/51/contributions/1164/ LOCATION: URL:https://events01.synchrotron.org.au/event/51/contributions/1164/ END:VEVENT BEGIN:VEVENT SUMMARY:Characterisation of the UK cement backfill material pre- and post- groundwater leaching experiments DTSTART;VALUE=DATE-TIME:20171102T030000Z DTEND;VALUE=DATE-TIME:20171102T031500Z DTSTAMP;VALUE=DATE-TIME:20260718T063601Z UID:indico-contribution-345-1158@events01.synchrotron.org.au DESCRIPTION:Speakers: Rita Vasconcelos (University of Sheffield)\nIn the U K\, the volume of intermediate level waste (ILW) requiring final disposal in a geological disposal facility\, is almost 450\,000 m3. In one of the U K conceptual scenarios for the geological disposal facility in a high-stre ngth crystalline rock\, the vaults will be backfilled with a cement-based material\, known as Nirex Reference Vault Backfill (NRVB). This material w ill provide a physical and chemical barrier to radionuclide release to the environment. Over the expected long lifetime performance of a cementitiou s backfill material\, NRVB will age and alter\, specifically due to intera ctions with groundwater. Understanding how these interactions will affect the properties of this material is of crucial importance for the developme nt of a robust safety case for the geological disposal facility. We here p resent the results of a detailed characterisation of NRVB pre- and post- g roundwater leaching experiments\, using three different types of groundwat er (granitic\, clay and saline groundwater)\, as analysed using convention al and advanced (e.g. tomography\, synchrotron XRD) techniques.\n\nhttps:/ /events01.synchrotron.org.au/event/51/contributions/1158/ LOCATION: URL:https://events01.synchrotron.org.au/event/51/contributions/1158/ END:VEVENT BEGIN:VEVENT SUMMARY:Identification of chemical form of stable carbon released from typ e 304 and 316 stainless-steel powders in alkaline solution and in acidic s olution under low-oxygen condition DTSTART;VALUE=DATE-TIME:20171102T043000Z DTEND;VALUE=DATE-TIME:20171102T044500Z DTSTAMP;VALUE=DATE-TIME:20260718T063601Z UID:indico-contribution-345-1128@events01.synchrotron.org.au DESCRIPTION:Speakers: Ryo Nakabayashi (Central Research Institute of Elect ric Power Industry)\nThe chemical form of carbon-14 released from irradiat ed stainless steel is a key parameter in the safety assessment of the sub- surface disposal system in Japan. In this study\, unirradiated 304 and 316 stainless-steel powders were immersed in HCl solution and in NaOH solutio n under a low-oxygen condition to identify the chemical form of the releas ed carbon. The main chemical forms of the carbon were formic and acetic ac ids in the HCl solution and colloidal carbon in the NaOH solution. Point a nalysis of the colloidal particles by transmission electron microscopy equ ipped with energy dispersive spectroscopy showed that C was accompanied wi th Fe and Cr. Fe and Cr tended to precipitate thermodynamically as hydroxi des in an alkaline environment\, suggesting that carbon sorbed onto the hy droxide. Meanwhile\, in the HCl solution\, the hydroxides did not precipit ate thermodynamically\, so carbon appeared to be released as an ionic form without the formation of metallic hydroxides.\n\nhttps://events01.synchro tron.org.au/event/51/contributions/1128/ LOCATION: URL:https://events01.synchrotron.org.au/event/51/contributions/1128/ END:VEVENT END:VCALENDAR