INNOVATION IN CONCRETE DESIGN FOR HAZARDOUS WASTE MANAGEMENT APPLICATIONS
Introduction
Promoting circular economy by using oil shale ash, an industrial waste product created in energy production in Estonia, as a supplementary cementitious material in concrete production.
Improving the mechanical properties of concrete by adding dispersed fibers.
Increasing the material's ability to shield neutrons by using basalt fibers infused with boron-oxide.
Four partners:
Latvia - Riga Technical University
Lithuania - Lithuanian Energy Institute
Estonia - University of Tartu
Norway - Arctic University of Norway
Timeframe: 2021 - 2024
Oil shale and oil shale ash
Oil shale has been used for energy production in Estonia over half a century.
High content of mineral matter
Burning 1 tonne → more than 0.5 tonnes of ash.
Oil shale ash has found very little use.
Between 2014 and 2020, ca. 55 million tonnes of oil shale processing residues was created in Estonia. And only 1-2% were utilized.
Chemical composition
Usability in concrete production
ISO standard EN 197-1: 2011 allows up to 55% of clincer replacement by puzzolans (siliceous and aluminous materials).
OSA is a promising material to be used as a barrier material to immobilize hazardous material (radioactive waste).
Fiber-reinforced concrete
Increase of flexural tensile strength for mechanical purposes.
Enhancement of fire resistance.
Replacement of traditionally used steel rebars by structurally dispersed fibers.
Reduction of early age shringage that causes crack formation during the hardenin process.
Basalt microfibers
uniform distribution due to similar specific gravity as the basic components of concrete
Cementation is a standard technique in radioactive waste management.
+ Suitable for a variety of waste + Simple, flexible, reliable and cost effective + Usually accepted for storage + Radiation resistance + Compatibility with many types of environmental conditions + Good actinide retention
- Increases the volume of final product.
Funding
Project promoter: Riga Technical University
The ICONDE project is one of the Baltic Research Program's projects, which is financially supported by the EEA Grants of Iceland, Liechtenstein and Norway. The implementation of the three year project started on May 1, 2021, and will continue until April 30, 2024.
Total eligible costs: 895 661.25 €
Grant financing: € 761,312.06
National co-financing: € 129,848.19
Conclusion
The development of new concrete mixtures as part of the ICONDE project aims to offer new solutions for radioactive waste management. The long-term lack of hazardous waste storage solutions and technologies is a problem for the entire Baltic region. An example of a source of large-scale radioactive waste of all stages is the decommissioning of the Ignalina Nuclear Power Plant (NPP). It will propose a new pathway for the utilization of existing industrial waste - the oil shale ash. This supports the UN's sustainable development goals for circular material flow. Advancement of the mechanical properties is expected to be achieved by the addition of fibers. Specific interest from the viewpoint of spent nuclear fuel storage solutions is the use of basalt-boron fibers in the concrete mixture to improve shielding against neutrons.
