Conveners
Actinides in Environmental and Life Sciences
- David Shuh (LBNL)
Actinides in Environmental and Life Sciences
- Daniel Grolimund (Paul Scherrer Institute, Swiss Light Source)
Actinides in Environmental and Life Sciences
- Daniel Grolimund (Paul Scherrer Institute, Swiss Light Source)
Actinides in Environmental and Life Sciences
- Rainer Dähn (Paul Scherrer Institut)
Dr
Tsuyoshi Yaita
(Japan Atomic Energy Agency)
21/05/2014, 10:20
Actinides in Environmental and Life Sciences
Oral
Three years have passed since Fukushima Dai-ichi Nuclear Power Plant (FDNP) Accident; a serious contamination problem still remains. Therefore, Japanese and local governments promotes the decontamination projects in which contaminated surface soil is removed and then, is moved it to interim storage area. Since soil waste is extremely large and space of an interim storage is limited, a...
Dr
Maxim Boyanov
(Argonne National Laboratory)
21/05/2014, 10:55
Actinides in Environmental and Life Sciences
Oral
In situ groundwater remediation or waste storage strategies often have the goal of limiting the mobility of a contaminant by decreasing its solubility in the passing aqueous phase. The chemical or enzymatic reduction of U(VI) to U(IV) presents an approach to achieve this goal by exploiting the lower solubility of uraninite (UO2) relative to that of U(VI) species. This property of U has led to...
Prof.
Rizlan Bernier-Latmani
(Ecole Polytechnique Federale de Lausanne (EPFL))
21/05/2014, 11:20
Actinides in Environmental and Life Sciences
Oral
U contamination as a result of U mining and processing is ubiquitous. In the environment, uranium is typically present in either its oxidized, soluble hexavalent state [U(VI)] or its reduced, insoluble tetravalent state [U(IV)]. The concentration of U was observed to increase as stream flowed through a wetland contaminated with U. This was unexpected as U is usually found in its sparingly...
Dr
Andreas Scheinost
(HZDR Institute of Resource Ecology)
21/05/2014, 11:55
Actinides in Environmental and Life Sciences
Oral
For the redox-reactive fission products and actinides Se, Tc, U, and Np, it is assumed that the strongly reducing conditions in deep underground, anoxic nuclear waste repositories will reduce their mobility, since their lower-oxidation states commonly form solids of very low solubility. This is not necessarily the case for Pu, where the hexa- and pentavalent aquo-complexes prevalent at higher...
Dr
Moritz Schmidt
(HZDR)
21/05/2014, 13:20
Actinides in Environmental and Life Sciences
Oral
The geochemistry of the actinides is of utmost importance in understanding and predicting their behavior in contaminated legacy sites as well as nuclear waste storage facilities. The unique chemistry of this group of elements including strong hydrolysis, complex redox chemistry, and the potential for polymerization reactions in combination with the actinides’ inherent radioactivity and...
Prof.
Stepan Kalmykov
(Lomonosov Moscow State University)
21/05/2014, 13:55
Actinides in Environmental and Life Sciences
Oral
Design of the nuclear waste repositories in geological conditions, development of effective remedial actions at radionuclide contaminated sites and evaluation of radioecological impact on the environment requires the molecular-level speciation of radionuclides. In this content the long-lived actinides are of the primary importance since their high radiotoxicity. Recently it have been...
Dr
Janos Osan
(Hungarian Academy of Sciences Centre for Energy Research)
21/05/2014, 14:30
Actinides in Environmental and Life Sciences
Oral
Argillaceous rock formations, due to their high clay content and low permeability, have significant radionuclide retention/retardation capacities, and are therefore in the focus for high level and long lived nuclear waste (HLW) repositories in several countries. In Hungary two geological sites (Gorica Block and W-Mecsek Anticline Block in the perianticlinal structure of W-Mecsek Mountains) of...
Prof.
Tobias Reich
(Johannes Gutenberg-Universität Mainz)
21/05/2014, 14:55
Actinides in Environmental and Life Sciences
Oral
In several European countries, e.g., France, Germany and Switzerland, argillaceous rocks are considered as a potential host rock for the construction of nuclear waste repositories. Detailed information on the interaction between the clay and the actinides, which are major contributors to the radiotoxicity of spent nuclear fuel after storage times of more than 1,000 years, is required for the...
Dr
Marika Vespa
(KIT-INE)
21/05/2014, 16:00
Actinides in Environmental and Life Sciences
Oral
Cement is an important constituent of the engineered barrier systems in underground repositories for low and intermediate level radioactive waste. Cement is used to solidify and stabilize the waste materials and, furthermore, it is used in huge amounts for the construction and backfilling of the cavern. The release of radionuclides from the cementitious near field into the underground is...
Dr
Sam Shaw
(University of Manchester)
21/05/2014, 16:25
Actinides in Environmental and Life Sciences
Oral
Many countries have a legacy of radioactively contaminated land and nuclear wastes. Current policy is to dispose of waste in a geological disposal facility, and decommission legacy nuclear sites over the next decades. These processes could lead to the release of radionuclides (e.g. 137Cs and Tc). Radionuclide mobility in the environment is often controlled by adsorption onto, and incorporation...
Dr
M. Janeth Lozano-Rodriguez
(1) HZDR, Institute of Resource Ecology, 01314 Dresden, Germany; (2) The Rossendorf Beamline at ESRF, CS 40220, 38043, Grenoble, CEDEX 9, France)
21/05/2014, 16:50
Actinides in Environmental and Life Sciences
Oral
Minor actinides such as Np, Am, and Cm contribute a major part of the heat load and radiotoxicity of spent nuclear fuel. Their separation and incorporation into stable ceramic phases may provide a route for their safe storage in deep-geological repositories or for their transmutation to short-lived nuclides. Natural monazites, early-lanthanide phosphate minerals of old age, contain up to 27 wt...
Ms
Melody Maloubier
(Institut de Chimie de Nice)
21/05/2014, 17:15
Actinides in Environmental and Life Sciences
Oral
The fate of radionuclides in the marine environment remains a major concern in our modern societies[1], specially after the recent event of Fukushima in 2011. Among the environmental compartments, the hydrosphere is ubiquitous and can transport compounds or elements over long distances. Among the radionuclides of concern, actinides are the heaviest elements involved in nuclear activities....
Prof.
Christophe DEN AUWER
(University Nice Sophia Antipolis, Nice Chemistry Institute)
22/05/2014, 08:40
Actinides in Environmental and Life Sciences
Oral
In case of accidental exposure to radioelements, internal actinide toxicity is related to both emitted radiation and to the in-vivo circulation scheme. Blocking the biological pathways of the actinides in the human (or more generally mammalian) systems and/or increasing their elimination rate would considerably decrease the toxicity of these elements. Overall the need for a better...
Prof.
Katherine Morris
(The University of Manchester)
22/05/2014, 09:15
Actinides in Environmental and Life Sciences
Oral
Understanding the behaviour of radionuclides in natural and engineered environments is key to the management and control of radioactively contaminated materials. Recent work has demonstrated that biogeochemical cycling of radionuclides is critical in controlling radionuclide behaviour in the shallow sub-surface. More recently, we have been exploring the role of microbial processes in...
