Objective
Clays are proposed as engineered barriers for radioactive waste in many European countries and safety analyses based on assessment of their performance are under way. Such analyses indicate that dense smectite clay provides a practically impermeable embedment of waste canisters which means that radionuclides will only move by diffusion. The mechanisms involved in such transport and the diffusive transport capacity are poorly known, however, and the value of smectite clay as barrier can therefore not be fully assessed until there is better understanding of their performance, which the project is expected to give.
The key factors are the physico/chemical properties of the smectite minerals and their spatial organisation with special respect to the physical state and composition of the porewater. These factors combine to yield the microstructural constitution of the clay which is known to be a function of the bulk density, dominant cation and temperature and which controls the retention and penetration of radionuclides. This means that the groundwater chemistry of the surroundings, i.e. the host rock or clay strata as well as the radionuclides and various species released from the smectite minerals, have an effect on the tightness of the clay barrier. This will be described in terms of the microstructure with special respect to radionuclide transport. Special attention will be paid to organophilic bentonites, i.e. smectite clays that are pretreated with certain organic substances. They have been found to sorb cations and high amounts of anions (iodine) as well. Preparation of organo-bentonites will be optimized towards retention of cations and anions according to the chemical spectrum of the relevant radionuclides contained in the waste material. Key data of the properties will be processed for incorporation into the nuclide diffusion model.
The work will comprise both theoretical and experimental studies, the common basic components being the microstructure and the chemical characterization of the bentonites used, which will be modeled such that the influence of density, organic pretreatment, porewater chemistry and temperature on the retention and penetration of radionuclides can be quantified. With help of the model, necessary data for the evaluation of the performance of clay barriers and guidelines for their practical realization will be obtained. The models developed for predicting radionuclide retention and transport in the cationic and anionic forms will serve as necessary instruments in the design of repositories as well as for safety assessment. They will hence be of significant assistance in the European work to deal with the issue of effective and safe isolation of radioactive waste.
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
LUND
Sweden
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.